ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Kinetics  (294)
  • American Association for the Advancement of Science (AAAS)  (294)
  • American Geophysical Union (AGU)
  • Annual Reviews
  • 1985-1989  (158)
  • 1980-1984  (136)
  • 1960-1964
  • 1940-1944
  • 1935-1939
Collection
Publisher
  • American Association for the Advancement of Science (AAAS)  (294)
  • American Geophysical Union (AGU)
  • Annual Reviews
  • Springer  (56)
  • Wiley-Blackwell  (5)
Years
Year
  • 1
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1988-11-25
    Description: The human immunodeficiency virus type 1 (HIV-1) shows extensive genetic variation and undergoes rapid evolution. The fidelity of purified HIV-1 reverse transcriptase was measured during DNA polymerization in vitro by means of three different assays. Reverse transcriptase from HIV-1 introduced base-substitution errors in DNA from the bacteriophage phi X174 amber3 at estimated frequencies of 1/2000 to 1/4000. Analyses of misincorporation rates opposite a single template adenine residue showed that HIV-1 reverse transcriptase catalyzed nucleotide mismatches with a specificity of A:C much greater than A:G greater than A:A. The high error rate of HIV-1 reverse transcriptase in vitro translates to approximately five to ten errors per HIV-1 genome per round of replication in vivo. This high error rate suggests that misincorporation by HIV-1 reverse transcriptase is, at least in part, responsible for the hypermutability of the AIDS virus. The specificity of misincorporation may provide a basis for the systematic construction of antiviral nucleosides.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Preston, B D -- Poiesz, B J -- Loeb, L A -- CA-07263-03/CA/NCI NIH HHS/ -- N01AI72654/AI/NIAID NIH HHS/ -- R35-CA-39903/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1988 Nov 25;242(4882):1168-71.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pathology, University of Washington, Seattle 98195.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2460924" target="_blank"〉PubMed〈/a〉
    Keywords: Avian Myeloblastosis Virus/enzymology ; Bacteriophage phi X 174/genetics ; DNA/*biosynthesis ; DNA Polymerase II/metabolism ; DNA, Viral/biosynthesis ; Electrophoresis, Polyacrylamide Gel ; HIV/*enzymology/genetics ; Kinetics ; Moloney murine leukemia virus/enzymology ; Mutation ; Nucleotides/metabolism ; RNA-Directed DNA Polymerase/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 1988-04-22
    Description: BC3H1 myocytes release membrane-bound alkaline phosphatase to the incubation medium upon stimulation with insulin, following a time course that is consistent with the generation of dimyristoylglycerol and the appearance of a putative insulin mediator in the extracellular medium. The use of specific blocking agents shows, however, that alkaline phosphatase release and dimyristoylglycerol production are independent processes and that the blockade of either event inhibits the production of insulin mediator. These experiments suggest a new model of insulin action.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Romero, G -- Luttrell, L -- Rogol, A -- Zeller, K -- Hewlett, E -- Larner, J -- AI 18000/AI/NIAID NIH HHS/ -- AM 14334/AM/NIADDK NIH HHS/ -- AM 22125/AM/NIADDK NIH HHS/ -- New York, N.Y. -- Science. 1988 Apr 22;240(4851):509-11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, University of Virginia School of Medicine, Charlottesville 22908.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3282305" target="_blank"〉PubMed〈/a〉
    Keywords: Alkaline Phosphatase/metabolism/secretion ; Animals ; Diglycerides/metabolism ; Enzyme Activation/drug effects ; Extracellular Space/enzymology ; Glycolipids/*physiology ; In Vitro Techniques ; Insulin/*pharmacology ; Kinetics ; Membrane Glycoproteins/*physiology ; Phosphatidylinositols/*physiology ; Pyruvate Dehydrogenase Complex/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1988-11-04
    Description: The anticodon has previously been shown to play a role in recognition of certain transfer RNAs by aminoacyl-tRNA synthetases; however, the extent to which this sequence dictates tRNA identity is generally unknown. To investigate the contribution of the anticodon to the identity of Escherichia coli methionine and valine tRNAs, in vitro transcripts of these tRNAs were prepared that contained normal and interchanged anticodon sequences. Transcripts containing wild-type tRNA sequences were excellent substrates for their respective cognate aminoacyl-tRNA synthetases and were effectively discriminated against by a variety of noncognate enzymes. The mutant tRNAs produced by switching the anticodon sequences lost their original tRNA identity and assumed an identity corresponding to the acquired anticodon sequence. These results indicate that the anticodon contains sufficient information to distinguish methionine and valine tRNAs with high fidelity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schulman, L H -- Pelka, H -- New York, N.Y. -- Science. 1988 Nov 4;242(4879):765-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Developmental Biology and Cancer, Albert Einstein College of Medicine, Bronx, New York 10461.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3055296" target="_blank"〉PubMed〈/a〉
    Keywords: *Anticodon ; Escherichia coli ; Kinetics ; Methionine-tRNA Ligase/metabolism ; *RNA, Transfer ; RNA, Transfer, Amino Acid-Specific/*physiology ; RNA, Transfer, Met/*physiology ; RNA, Transfer, Val/*physiology ; Substrate Specificity ; *Transfer RNA Aminoacylation ; Valine-tRNA Ligase/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 1988-11-25
    Description: A cell-free translation system has been constructed that uses a continuous flow of the feeding buffer [including amino acids, adenosine triphosphate (ATP), and guanosine triphosphate (GTP)] through the reaction mixture and a continuous removal of a polypeptide product. Both prokaryotic (Escherichia coli) and eukaryotic (wheat embryos, Triticum sp.) versions of the system have been tested. In both cases the system has proven active for long times, synthesizing polypeptides at a high constant rate for tens of hours. With the use of MS2 phage RNA or brome mosaic virus RNA 4 as templates, 100 copies of viral coat proteins per RNA were synthesized for 20 hours in the prokaryotic or eukaryotic system, respectively. With synthetic calcitonin messenger RNA, 150 to 300 copies of calcitonin polypeptide were produced per messenger RNA in both types of continuous translation systems for 40 hours.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Spirin, A S -- Baranov, V I -- Ryabova, L A -- Ovodov, S Y -- Alakhov, Y B -- New York, N.Y. -- Science. 1988 Nov 25;242(4882):1162-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Protein Research, Academy of Sciences, Moscow Region, USSR.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3055301" target="_blank"〉PubMed〈/a〉
    Keywords: Bacteriophages/genetics ; Calcitonin/biosynthesis/genetics ; Capsid/biosynthesis/genetics ; Electrophoresis ; Escherichia coli/*metabolism ; Kinetics ; Mosaic Viruses/genetics ; *Peptide Biosynthesis ; Plants/*metabolism ; *Protein Biosynthesis ; RNA, Messenger/metabolism ; RNA, Viral/genetics ; Ribosomes/metabolism ; Templates, Genetic ; Triticum
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1988-01-08
    Description: The Bacillus subtilis ribonuclease P consists of a protein and an RNA. At high ionic strength the reaction is protein-independent; the RNA alone is capable of cleaving precursor transfer RNA, but the turnover is slow. Kinetic analyses show that high salt concentrations facilitate substrate binding in the absence of the protein, probably by decreasing the repulsion between the polyanionic enzyme and substrate RNAs, and also slow product release and enzyme turnover. It is proposed that the ribonuclease P protein, which is small and basic, provides a local pool of counter-ions that facilitates substrate binding without interfering with rapid product release.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Reich, C -- Olsen, G J -- Pace, B -- Pace, N R -- GM34527/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1988 Jan 8;239(4836):178-81.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, Indiana University, Bloomington 47405.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3122322" target="_blank"〉PubMed〈/a〉
    Keywords: Bacillus subtilis/*enzymology ; Endoribonucleases/*physiology ; Kinetics ; Nucleic Acid Precursors/metabolism ; RNA, Transfer/metabolism ; Ribonuclease P ; Ribonucleoproteins/*physiology ; Structure-Activity Relationship
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 1988-12-16
    Description: The fidelity of protein biosynthesis in any cell rests on the accuracy of aminoacylation of tRNA. The exquisite specificity of this reaction is critically dependent on the correct recognition of tRNA by aminoacyl-tRNA synthetases. It is shown here that the relative concentrations of a tRNA and its cognate aminoacyl-tRNA synthetase are normally well balanced and crucial for maintenance of accurate aminoacylation. When Escherichia coli Gln-tRNA synthetase is overproduced in vivo, it incorrectly acylates the supF amber suppressor tRNA(Tyr) with Gln. This effect is abolished when the intracellular concentration of the cognate tRNA(Gln2) is also elevate. These data indicate that the presence of aminoacyl-tRNA synthetase and the cognate tRNAs in complexed form, which requires the proper balance of the two macromolecules, is critical in maintaining the fidelity of protein biosynthesis. Thus, limits exist on the relative levels of tRNAs and aminoacyl-tRNA synthetases within a cell.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Swanson, R -- Hoben, P -- Sumner-Smith, M -- Uemura, H -- Watson, L -- Soll, D -- New York, N.Y. -- Science. 1988 Dec 16;242(4885):1548-51.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3144042" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acyl-tRNA Synthetases/genetics/*metabolism ; Escherichia coli/enzymology/*genetics ; Kinetics ; Plasmids ; RNA, Transfer, Amino Acid-Specific/*metabolism ; RNA, Transfer, Gln/*metabolism ; beta-Galactosidase/genetics/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 1988-12-09
    Description: Potassium channels in neurons are linked by guanine nucleotide binding (G) proteins to numerous neurotransmitter receptors. The ability of Go, the predominant G protein in the brain, to stimulate potassium channels was tested in cell-free membrane patches of hippocampal pyramidal neurons. Four distinct types of potassium channels, which were otherwise quiescent, were activated by both isolated brain G0 and recombinant Go alpha. Hence brain Go can couple diverse brain potassium channels to neurotransmitter receptors.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉VanDongen, A M -- Codina, J -- Olate, J -- Mattera, R -- Joho, R -- Birnbaumer, L -- Brown, A M -- DK-19318/DK/NIDDK NIH HHS/ -- HL-31154/HL/NHLBI NIH HHS/ -- HL-37044/HL/NHLBI NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1988 Dec 9;242(4884):1433-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology and Molecular Biophysics, Baylor College of Medicine, Houston, TX 77030.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3144040" target="_blank"〉PubMed〈/a〉
    Keywords: Adenylyl Imidodiphosphate/pharmacology ; Animals ; Cattle ; Electric Conductivity ; GTP-Binding Proteins/*pharmacology ; Hippocampus/*physiology ; In Vitro Techniques ; Kinetics ; Macromolecular Substances ; Membrane Potentials/drug effects ; Potassium Channels/drug effects/*physiology ; Pyramidal Tracts/physiology ; Rats ; Recombinant Proteins/*pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 1988-06-10
    Description: Proteins undergo a series of nonenzymatic reactions with glucose over time to form advanced glycosylation end products (AGEs). Macrophages have a receptor that recognizes the AGE moiety and mediates the uptake and degradation of AGE proteins. This removal process is associated with the production and secretion of cachectin (tumor necrosis factor) and interleukin-1, two cytokines with diverse and seemingly paradoxical biological activities. The localized release and action of these cytokines could account for the coordinated removal and replacement of senescent extracellular matrix components in normal tissue homeostasis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Vlassara, H -- Brownlee, M -- Manogue, K R -- Dinarello, C A -- Pasagian, A -- R01-AI15674/AI/NIAID NIH HHS/ -- R01-AM19655/AM/NIADDK NIH HHS/ -- R01-AM33861/AM/NIADDK NIH HHS/ -- New York, N.Y. -- Science. 1988 Jun 10;240(4858):1546-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Medical Biochemistry, Rockefeller University, New York, NY 10021.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3259727" target="_blank"〉PubMed〈/a〉
    Keywords: Glycosylation ; Humans ; Interleukin-1/*biosynthesis/genetics ; Kinetics ; Membrane Glycoproteins/*physiology ; Monocytes/*metabolism ; Protein Biosynthesis ; RNA, Messenger/genetics ; Tumor Necrosis Factor-alpha/*biosynthesis/genetics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1988-06-17
    Description: Biochemical and electrophysiological studies suggest that adenosine 3',5'-monophosphate (cAMP)-dependent phosphorylation of the nicotinic acetylcholine receptor channel is functionally significant because it modifies the receptor's rate of desensitization to acetylcholine. In studies that support this conclusion researchers have used forskolin to stimulate cAMP-dependent phosphorylation in intact muscle. It is now shown that although forskolin facilitated desensitization in voltage-clamped rat muscle, this effect was not correlated with the abilities of forskolin and forskolin analogs to activate adenylate cyclase or phosphorylate the receptor. Furthermore, elevation of intracellular cAMP or addition of the catalytic subunit of A-kinase failed to alter desensitization. Therefore, in intact skeletal muscle, cAMP-dependent phosphorylation does not modulate desensitization.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wagoner, P K -- Pallotta, B S -- GM32211/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1988 Jun 17;240(4859):1655-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Pharmacology, Glaxo Research Laboratories, Chapel Hill, NC 27599.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2454507" target="_blank"〉PubMed〈/a〉
    Keywords: 1-Methyl-3-isobutylxanthine/pharmacology ; Acetylcholine/pharmacology ; Adenylyl Cyclases/metabolism ; Animals ; Bucladesine/pharmacology ; Colforsin/*pharmacology ; Cyclic AMP/analogs & derivatives/*pharmacology ; Electric Conductivity ; Enzyme Activation/drug effects ; Kinetics ; Muscles/*metabolism ; Phosphorylation ; Rats ; Receptors, Cholinergic/drug effects/*physiology ; Torpedo/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1988-10-07
    Description: The enzymes adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase (protein kinase A) and protein kinase C regulate the activity of a diverse group of cellular proteins including membrane ion channel proteins. When protein kinase A was stimulated in cardiac ventricular myocytes with the membrane-soluble cAMP analog 8-chlorphenylthio cAMP (8-CPT cAMP), the amplitude of the delayed-rectifier potassium current (IK) doubled when recorded at 32 degrees C but was not affected at 22 degrees C. In contrast, modulation of the calcium current (ICa) by 8-CPT cAMP was independent of temperature with similar increases in ICa occurring at both temperatures. Stimulation of protein kinase C by phorbol 12,13-dibutyrate also enhanced IK in a temperature-dependent manner but failed to increase ICa at either temperature. Thus, cardiac delayed-rectifier potassium but not calcium channels are regulated by two distinct protein kinases in a similar temperature-dependent fashion.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Walsh, K B -- Kass, R S -- New York, N.Y. -- Science. 1988 Oct 7;242(4875):67-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology, University of Rochester, School of Medicine and Dentistry, NY 14642.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2845575" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cyclic AMP/*analogs & derivatives/pharmacology ; Guinea Pigs ; Heart/*physiology ; Homeostasis ; In Vitro Techniques ; Kinetics ; Membrane Potentials ; Potassium Channels/*physiology ; Protein Kinase C/*metabolism ; Protein Kinases/*metabolism ; Thermodynamics ; Thionucleotides/*pharmacology ; Ventricular Function
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-05-05
    Description: Tumor promoters may bring about events that lead to neoplastic transformation by inducing specific promotion-relevant effector genes. Functional activation of the transacting transcription factor AP-1 by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) may play an essential role in this process. Clonal genetic variants of mouse epidermal JB6 cells that are genetically susceptible (P+) or resistant (P-) to promotion of transformation by TPA were transfected with 3XTRE-CAT, a construct that has AP-1 cis-enhancer sequences attached to a reporter gene encoding chloramphenicol acetyltransferase (CAT). Transfected JB6 P+, but not P- variants, showed TPA-inducible CAT synthesis. Epidermal growth factor, another transformation promoter in JB6 cells, also caused P+ specific induction of CAT gene expression. These results demonstrate an association between induced AP-1 function and sensitivity to promotion of neoplastic transformation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bernstein, L R -- Colburn, N H -- New York, N.Y. -- Science. 1989 May 5;244(4904):566-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Johns Hopkins University, Department of Biology, Baltimore, MD 21218.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2541502" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cell Line ; *Cell Transformation, Neoplastic ; Chloramphenicol O-Acetyltransferase/genetics ; Cloning, Molecular ; DNA-Binding Proteins/genetics/*physiology ; Epidermal Growth Factor/pharmacology ; Epidermis ; Gene Expression Regulation ; Genetic Variation ; Kinetics ; Mice ; Nucleic Acid Hybridization ; Plasmids ; Promoter Regions, Genetic ; Proto-Oncogene Proteins ; Proto-Oncogene Proteins c-jun ; Simplexvirus/genetics ; Tetradecanoylphorbol Acetate/*pharmacology ; Transcription Factors/genetics/*physiology ; Transfection
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-04-28
    Description: The specific hydrolysis of unactivated esters bearing an R or S enantiomeric alcohol has been achieved by two separate classes of catalytic antibodies induced to bind either the R or S substrates. The antibodies exhibit rate accelerations (10(3) to 10(5] above background hydrolysis that, coupled with their antipodal specificity, provide a novel set of reagents for use in synthesis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Janda, K D -- Benkovic, S J -- Lerner, R A -- New York, N.Y. -- Science. 1989 Apr 28;244(4903):437-40.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, Research Institute of Scripps Clinic, La Jolla, CA 92037.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2717936" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Antibodies, Monoclonal/immunology ; Antibody Specificity ; Antigens/immunology ; Benzyl Alcohols/metabolism ; *Catalysis ; Esters/metabolism ; Haptens ; Hemocyanin/immunology ; Hydrolysis ; Immunization ; Kinetics ; Lipase/*metabolism ; Mice ; Mice, Inbred A ; Molecular Structure ; Organophosphonates/immunology ; Stereoisomerism ; Substrate Specificity
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Publication Date: 1989-03-10
    Description: Antisense RNA-mediated inhibition of gene expression was used to investigate the biological function of the c-raf-1 gene in a radiation-resistant human squamous carcinoma cell line, SQ-20B. S1 nuclease protection assays revealed that transfection of full-length raf complementary DNA in the antisense orientation (AS) leads to a specific reduction (greater than tenfold) of steady-state levels of the endogenous c-raf-1 sense (S) transcript in SQ-20B cells. In nude mice, the malignant potential of SQ-20B cells transfected with raf (S) was significantly increased relative to that of SQ-20B cells transfected with raf (AS). SQ-20B cells containing transfected raf (S) maintained a radiation-resistant phenotype as compared to those cells harboring the AS version, which appeared to have enhanced radiation sensitivity. These data indicate that the reduced expression of endogenous c-raf-1 is sufficient to modulate the tumorigenicity and the radiation-resistant phenotype of SQ-20B cells, thus implicating c-raf-1 in a pathway important to the genesis of this type of cancer.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kasid, U -- Pfeifer, A -- Brennan, T -- Beckett, M -- Weichselbaum, R R -- Dritschilo, A -- Mark, G E -- New York, N.Y. -- Science. 1989 Mar 10;243(4896):1354-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Radiation Medicine, Vincent T. Lombardi Comprehensive Cancer Research Center, Georgetown University Medical Center, Washington 20007.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2466340" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Blotting, Southern ; Carcinoma, Squamous Cell/*genetics ; Cell Line ; Cell Survival/*radiation effects ; Clone Cells ; Dose-Response Relationship, Radiation ; *Gene Expression Regulation ; Humans ; Kinetics ; Mice ; Mice, Nude ; Neoplasm Transplantation ; Nucleic Acid Hybridization ; *Proto-Oncogenes ; RNA/*genetics ; RNA, Antisense ; RNA, Messenger/*antagonists & inhibitors ; Transcription, Genetic ; Transfection ; Transplantation, Heterologous ; Tumor Cells, Cultured/*radiation effects
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-06-09
    Description: Two types of potassium-selective channels activated by intracellular arachidonic acid or phosphatidylcholine have been found in neonatal rat atrial cells. In inside-out patches, arachidonic acid and phosphatidylcholine each opened outwardly rectifying potassium-selective channels with conductances of 160 picosiemens (IK.AA) and 68 picosiemens (IK.PC), respectively. These potassium channels were not sensitive to internally applied adenosine triphosphate (ATP), magnesium, or calcium. Lowering the intracellular pH from 7.2 to 6.8 or 6.4 reversibly increased IK.AA channel activity three- or tenfold, respectively. A number of fatty acid derivatives were tested for their ability to activate IK.AA. These potassium-selective channels may help explain the increase in potassium conductance observed in ischemic cells and raise the possibility that fatty acid derivatives act as second messengers.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kim, D -- Clapham, D E -- HL 34873/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1989 Jun 9;244(4909):1174-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, Mayo Foundation, Rochester, MN 55905.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2727703" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Animals, Newborn ; Arachidonic Acids/*pharmacology ; Atrial Function ; Heart/*physiology ; Hydrogen-Ion Concentration ; In Vitro Techniques ; Kinetics ; Membrane Potentials ; Phosphatidylcholines/*pharmacology ; Potassium Channels/drug effects/*physiology ; Rats
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Publication Date: 1989-09-15
    Description: The neutrophil Mac-1 and gp100MEL-14 adhesion proteins are involved in neutrophil extravasation during inflammation. Both the expression and activity of Mac-1 are greatly increased after neutrophil activation. In contrast, neutrophils shed gp100MEL-14 from the cell surface within 4 minutes after activation with chemotactic factors or phorbol esters, releasing a 96-kilodalton fragment of the antigen into the supernatant. Immunohistology showed that gp100MEL-14 was downregulated on neutrophils that had extravasated into inflamed tissue. The gp100MEL-14 adhesion protein may participate in the binding of unactivated neutrophils to the endothelium; rapid shedding of gp100MEL-14 may prevent extravasation into and damage of normal tissues by activated neutrophils.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kishimoto, T K -- Jutila, M A -- Berg, E L -- Butcher, E C -- AI 19957/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 1989 Sep 15;245(4923):1238-41.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pathology, Stanford University, CA 94305.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2551036" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Antigens, Differentiation/*immunology ; Antigens, Surface/*immunology ; Bone Marrow Cells ; Cell Adhesion ; Cell Adhesion Molecules ; Chemotactic Factors/*physiology ; Complement C5/physiology ; Complement C5a ; Fluorescent Antibody Technique ; Interleukin-1/physiology ; Interleukin-8 ; Kinetics ; Leukotriene B4/physiology ; Lipopolysaccharides/physiology ; Lymphocyte Activation ; Macrophage Activation ; Macrophage-1 Antigen ; Mice ; Mice, Inbred BALB C ; Neutrophils/cytology/*immunology ; Tetradecanoylphorbol Acetate ; Tumor Necrosis Factor-alpha/physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Publication Date: 1989-04-07
    Description: Protein engineering and x-ray crystallography have been used to study the role of a surface loop that is present in pancreatic phospholipases but is absent in snake venom phospholipases. Removal of residues 62 to 66 from porcine pancreatic phospholipase A2 does not change the binding constant for micelles significantly, but it improves catalytic activity up to 16 times on micellar (zwitterionic) lecithin substrates. In contrast, the decrease in activity on negatively charged substrates is greater than fourfold. A crystallographic study of the mutant enzyme shows that the region of the deletion has a well-defined structure that differs from the structure of the wild-type enzyme. No structural changes in the active site of the enzyme were detected.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kuipers, O P -- Thunnissen, M M -- de Geus, P -- Dijkstra, B W -- Drenth, J -- Verheij, H M -- de Haas, G H -- New York, N.Y. -- Science. 1989 Apr 7;244(4900):82-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Utrecht, The Netherlands.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2704992" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Animals ; Crystallography ; Enzyme Activation ; Kinetics ; Molecular Sequence Data ; Mutation ; Pancreas/enzymology ; Phospholipases/*metabolism ; Phospholipases A/genetics/*metabolism/physiology ; Phospholipases A2 ; *Protein Conformation ; Snake Venoms/analysis ; Structure-Activity Relationship ; Swine
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-08-04
    Description: The origin of allostery is an unanswered question in the evolution of complex regulatory proteins. Anabolic ornithine transcarbamoylase, a trimer of identical subunits, is not an allosteric enzyme per se. However, when the active-site residue arginine-106 of the Escherichia coli enzyme is replaced with a glycine through site-directed mutagenesis, the resultant mutant enzyme manifests substrate cooperativity that is absent in the wild-type enzyme. Both homotropic and heterotropic interactions occur in the mutant enzyme. The initial velocity saturation curves of the substrates, carbamoyl phosphate and L-ornithine, conform to the Hill equation. The observed cooperativity depends on substrate but not enzyme concentration. The finding underscores the possibility that a single mutation of the enzyme in the cell could turn transcarbamoylation into a regulatory junction in the biosynthesis of L-arginine and urea.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kuo, L C -- Zambidis, I -- Caron, C -- DK01721/DK/NIDDK NIH HHS/ -- DK38089/DK/NIDDK NIH HHS/ -- New York, N.Y. -- Science. 1989 Aug 4;245(4917):522-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Metcalf Center for Science and Engineering, Boston University, MA 02215.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2667139" target="_blank"〉PubMed〈/a〉
    Keywords: Allosteric Regulation ; Binding Sites ; Carbamyl Phosphate/metabolism ; Escherichia coli/*enzymology ; Glycine ; Kinetics ; Macromolecular Substances ; *Mutation ; Ornithine/metabolism ; Ornithine Carbamoyltransferase/*genetics/metabolism ; Structure-Activity Relationship ; Zinc/pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Publication Date: 1989-07-07
    Description: Basic fibroblast growth factor (bFGF) participates in many processes including early developmental events, angiogenesis, wound healing, and maintenance of neuronal cell viability. A 130-kilodalton protein was isolated on the basis of its ability to specifically bind to bFGF. A complementary DNA clone was isolated with an oligonucleotide probe corresponding to determined amino acid sequences of tryptic peptide fragments of the purified protein. The putative bFGF receptor encoded by this complementary DNA is a transmembrane protein that contains three extracellular immunoglobulin-like domains, an unusual acidic region, and an intracellular tyrosine kinase domain. These domains are arranged in a pattern that is different from that of any growth factor receptor described.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lee, P L -- Johnson, D E -- Cousens, L S -- Fried, V A -- Williams, L T -- CA 21765/CA/NCI NIH HHS/ -- R01 HL32898/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1989 Jul 7;245(4913):57-60.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, Department of Medicine, University of California, San Francisco 94143.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2544996" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Animals ; Base Sequence ; Cells, Cultured ; Chick Embryo ; *Cloning, Molecular ; DNA/*genetics ; Fibroblast Growth Factors/*genetics ; Kinetics ; Mice ; Molecular Sequence Data ; Peptide Fragments/analysis ; Receptors, Cell Surface/*genetics/metabolism ; Receptors, Fibroblast Growth Factor ; Recombinant Proteins/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-11-17
    Description: Rana esculenta tropomyosin assembles in vivo into a coiled-coil alpha helix from two different subunits, alpha and beta, which are present in about equal concentrations. Although the native composition is alpha beta, a mixture of equal amounts of alpha alpha and beta beta is produced by refolding dissociated alpha and beta at low temperature in vitro. Refolding kinetics showed that alpha alpha formed first and was relatively stable with regard to chain exchange below approximately 20 degrees C. Equilibration of the homodimer mixture at 30 degrees and 34 degrees C for long times, however, resulted in the formation of the native alpha beta molecule by chain exchange. Biosynthesis of alpha beta from separate alpha and beta genes is, therefore, favored thermodynamically over the formation of homodimers, and biological factors need not be invoked to explain the preferred native alpha beta composition.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lehrer, S S -- Qian, Y D -- Hvidt, S -- HL22461/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1989 Nov 17;246(4932):926-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Muscle Research, Boston Biomedical Research Institute, MA 02114.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2814515" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Kinetics ; Macromolecular Substances ; Muscle, Smooth/metabolism ; Muscles/metabolism ; Myocardium/metabolism ; Protein Conformation ; Protein Denaturation ; Protein Processing, Post-Translational ; Rana esculenta ; Thermodynamics ; Tropomyosin/genetics/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Publication Date: 1989-01-13
    Description: An important question in protein folding is whether the natural amino and carboxyl termini and the given order of secondary structure segments are critical to the stability and to the folding pathway of proteins. Here it is shown that two circularly permuted versions of the gene of a single-domain beta alpha barrel enzyme can be expressed in Escherichia coli. The variants are enzymically active and are practically indistinguishable from the original enzyme by several structural and spectroscopic criteria, despite the creation of new termini and the cleavage of a surface loop. This novel genetic approach should be useful for protein folding studies both in vitro and in vivo.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Luger, K -- Hommel, U -- Herold, M -- Hofsteenge, J -- Kirschner, K -- New York, N.Y. -- Science. 1989 Jan 13;243(4888):206-10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Abteilung Biophysikalische Chemie, Universitat Basel, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2643160" target="_blank"〉PubMed〈/a〉
    Keywords: *Aldose-Ketose Isomerases ; Amino Acid Sequence ; Base Sequence ; Carbohydrate Epimerases/*genetics/metabolism ; Circular Dichroism ; *Cloning, Molecular ; Enzyme Stability ; Escherichia coli/*enzymology/genetics ; *Genes ; Genetic Variation ; Kinetics ; Molecular Sequence Data ; *Protein Conformation ; Spectrometry, Fluorescence ; Spectrophotometry, Ultraviolet
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-11-03
    Description: An important control point in gene expression is at the level of messenger RNA (mRNA) stability. The mRNAs of certain regulatory cellular proteins such as oncogenes, cytokines, lymphokines, and transcriptional activators are extremely labile. These messages share a common AUUUA pentamer in their 3' untranslated region, which confers cytoplasmic instability. A cytosolic protein was identified that binds specifically to RNA molecules containing four reiterations of the AUUUA structural element. This protein consists of three subunits and binds rapidly to AUUUA-containing RNA. Such protein-RNA complexes are resistant to the actions of denaturing and reducing agents, demonstrating very stable binding. The time course, stability, and specificity of the protein-AUUUA interaction suggests the possibility that the formation of this complex may target susceptible mRNA for rapid cytoplasmic degradation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Malter, J S -- CA01427-01/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1989 Nov 3;246(4930):664-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pathology, Tulane University School of Medicine, New Orleans, LA 70112.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2814487" target="_blank"〉PubMed〈/a〉
    Keywords: Base Sequence ; Binding, Competitive ; Carrier Proteins/isolation & purification/*metabolism ; Cell Line ; Humans ; Kinetics ; Macromolecular Substances ; Molecular Weight ; *Nucleocytoplasmic Transport Proteins ; RNA, Messenger/*metabolism ; *RNA-Binding Proteins ; Ribonuclease, Pancreatic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Publication Date: 1989-06-09
    Description: Arachidonic acid, as well as fatty acids that are not substrates for cyclooxygenase and lipoxygenase enzymes, activated a specific type of potassium channel in freshly dissociated smooth muscle cells. Activation occurred in excised membrane patches in the absence of calcium and all nucleotides. Therefore signal transduction pathways that require such soluble factors, including the NADPH-dependent cytochrome P450 pathway, do not mediate the response. Thus, fatty acids directly activate potassium channels and so may constitute a class of signal molecules that regulate ion channels.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ordway, R W -- Walsh, J V Jr -- Singer, J J -- DK-31620/DK/NIDDK NIH HHS/ -- New York, N.Y. -- Science. 1989 Jun 9;244(4909):1176-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology, University of Massachusetts Medical School, Worcester 01655.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2471269" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Arachidonic Acid ; Arachidonic Acids/*pharmacology ; Bufo marinus ; Fatty Acids, Nonesterified/*pharmacology ; In Vitro Techniques ; Ion Channels/drug effects/*physiology ; Kinetics ; Membrane Potentials/drug effects ; Muscle, Smooth/*physiology ; Stomach/physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-12-22
    Description: The contribution of the anticodon to the discrimination between cognate and noncognate tRNAs by Escherichia coli Arg-tRNA synthetase has been investigated by in vitro synthesis and aminoacylation of elongator methionine tRNA (tRNA(mMet) mutants. Substitution of the Arg anticodon CCG for the Met anticodon CAU leads to a dramatic increase in Arg acceptance by tRNA(mMet). A nucleotide (A20) previously identified by others in the dihydrouridine loop of tRNA(Arg)s makes a smaller contribution to the conversion of tRNA(mMet) identity from Met to Arg. The combined anticodon and dihydrouridine loop mutations yield a tRNA(mMet) derivative that is aminoacylated with near-normal kinetics by the Arg-tRNA synthetase.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schulman, L H -- Pelka, H -- New York, N.Y. -- Science. 1989 Dec 22;246(4937):1595-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Developmental Biology and Cancer, Albert Einstein College of Medicine, Bronx, NY 10461.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2688091" target="_blank"〉PubMed〈/a〉
    Keywords: Anticodon/*genetics ; Arginine-tRNA Ligase/metabolism ; Base Sequence ; Escherichia coli/enzymology/genetics ; Kinetics ; Methionine-tRNA Ligase/metabolism ; Molecular Sequence Data ; Nucleic Acid Conformation ; RNA, Transfer/*genetics ; RNA, Transfer, Amino Acid-Specific/*genetics ; RNA, Transfer, Arg/*genetics ; Substrate Specificity ; T-Phages/genetics ; Transcription, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Publication Date: 1989-06-09
    Description: Vasoactive intestinal peptide (VIP) labeled with 125I, [Tyr10-125I]VIP, can be hydrolyzed by immunoglobulin G (IgG) purified from a human subject, as judged by trichloroacetic acid precipitation and reversed-phase high-performance liquid chromatography (HPLC). The hydrolytic activity was precipitated by antibody to human IgG, it was bound by immobilized protein G and showed a molecular mass close to 150 kilodaltons by gel filtration chromatography, properties similar to those of authentic IgG. The Fab fragment, prepared from IgG by papain treatment, retained the VIP hydrolytic activity of the IgG. Peptide fragments produced by treatment of VIP with the antibody fraction were purified by reversed-phase HPLC and identified by fast atom bombardment-mass spectrometry and peptide sequencing. The scissile bond in VIP deduced from these experiments was Gln16-Met17. The antibody concentration (73.4 fmol per milligram of IgG) and the Kd (0.4 nM) were computed from analysis of VIP binding under conditions that did not result in peptide hydrolysis. Analysis of the antibody-mediated VIP hydrolysis at varying concentrations of substrate suggested conformity with Michaelis-Menton kinetics (Km). The values for Km (37.9 X 10(-9) M) and the turnover number kcat (15.6 min-1) suggested relatively tight VIP binding and a moderate catalytic efficiency of the antibody.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Paul, S -- Volle, D J -- Beach, C M -- Johnson, D R -- Powell, M J -- Massey, R J -- HL 35506/HL/NHLBI NIH HHS/ -- HL 40348/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1989 Jun 9;244(4909):1158-62.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, University of Nebraska Medical Center, Omaha 68105.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2727702" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; *Autoantibodies ; Catalysis ; Chromatography, High Pressure Liquid ; Humans ; Hydrolysis ; Immunoglobulin Fab Fragments ; *Immunoglobulin G ; Kinetics ; Molecular Sequence Data ; Peptide Fragments/isolation & purification ; Vasoactive Intestinal Peptide/*immunology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-11-17
    Description: A phosphonate monoester, m-carboxyphenyl phenylacetamidomethylphosphonate, has been found to be a specific inhibitor of the class C beta-lactamase of Enterobacter cloacae P99. Inactivation is rapid (10(3) per second per molar concentration) and reactivation very slow (2.2 X 10(-6) per second). Apparently concerted with the inactivation, one equivalent (with respect to the enzyme) of m-hydroxybenzoate is released. Reactivation is accelerated by hydroxylamine and benzohydroxamate. This suggests that the loss of enzyme activity is due to phosphonylation of an active site functional group. This discovery holds the promise of a new general class of beta-lactamase inhibitors and, perhaps, antibiotics.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pratt, R F -- New York, N.Y. -- Science. 1989 Nov 17;246(4932):917-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Chemistry Department, Wesleyan University, Middletown, CT 06457.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2814513" target="_blank"〉PubMed〈/a〉
    Keywords: Enterobacter/*enzymology ; Enterobacteriaceae/*enzymology ; Hydroxamic Acids/pharmacology ; Hydroxylamine ; Hydroxylamines/pharmacology ; Kinetics ; Organophosphorus Compounds/*pharmacology ; Protein Binding ; *beta-Lactamase Inhibitors
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Publication Date: 1989-04-28
    Description: The rapid transductional sequences initiated by interferon-gamma (IFN-gamma) on binding to its receptor regulate functional and genomic responses in many cells but are not well defined. Induction of macrophage activation is an example of such functional and genomic changes in response to IFN-gamma. Addition of IFN-gamma to murine macrophages, at activating concentrations, produced rapid (within 60 seconds) alkalinization of the cytosol and a concomitant, rapid influx of 22Na+. Amiloride inhibited the ion fluxes and the accumulation of specific messenger RNA for two genes induced by IFN-gamma (the early gene JE and the beta chain of the class II major histocompatibility complex gene I-A). The data indicate that IFN-gamma initiates rapid exchange of Na+ and H+ by means of the Na+/H+ antiporter and that these amiloride-sensitive ion fluxes are important to some of the genomic effects of IFN-gamma.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Prpic, V -- Yu, S F -- Figueiredo, F -- Hollenbach, P W -- Gawdi, G -- Herman, B -- Uhing, R J -- Adams, D O -- New York, N.Y. -- Science. 1989 Apr 28;244(4903):469-71.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pathology, Duke University Medical Center, Durham, NC 27710.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2541500" target="_blank"〉PubMed〈/a〉
    Keywords: Amiloride/pharmacology ; Animals ; Carrier Proteins/antagonists & inhibitors/metabolism ; Cells, Cultured ; Cytosol/metabolism ; *Gene Expression Regulation ; Histocompatibility Antigens Class II/*genetics ; Hydrogen-Ion Concentration ; Interferon-gamma/*physiology ; Kinetics ; Macrophage Activation ; Macrophages/drug effects/metabolism ; Mice ; *Protons ; RNA, Messenger/biosynthesis ; Sodium/*metabolism ; Sodium-Hydrogen Antiporter
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Publication Date: 1989-08-11
    Description: The endogenous c-mos product, pp39mos, is required for progesterone-induced meiotic maturation in Xenopus oocytes. Treatment of oocytes with progesterone induced a rapid increase in pp39mos that preceded both the activation of maturation promoting factor (MPF) and germinal vesicle breakdown (GVBD). Microinjection of synthetic mos RNA into oocytes activated MPF and induced GVBD in the absence of progesterone. Thus, the mos proto-oncogene product may qualify as a candidate "initiator" protein of MPF and is at least one of the "triggers" for G2 to M transition.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sagata, N -- Daar, I -- Oskarsson, M -- Showalter, S D -- Vande Woude, G F -- N01-CO-74101/CO/NCI NIH HHS/ -- New York, N.Y. -- Science. 1989 Aug 11;245(4918):643-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉BRI-Basic Research Program, National Cancer Institute, Frederick Cancer Research Facility, MD 21701.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2474853" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Base Sequence ; Cycloheximide/pharmacology ; Female ; Growth Substances/physiology ; Kinetics ; Maturation-Promoting Factor ; Meiosis/drug effects ; Microinjections ; Oocytes/*physiology ; Progesterone/pharmacology ; Protein Biosynthesis ; Proto-Oncogene Proteins/genetics/*physiology ; Proto-Oncogene Proteins c-mos ; RNA/genetics ; Transcription, Genetic ; Transfection ; Xenopus
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Publication Date: 1989-02-17
    Description: Salmonella bacteria are capable of entering (invading) and multiplying within eukaryotic cells. Stable adherence to and invasion of epithelial cells by S. choleraesuis and S. typhimurium were found to require de novo synthesis of several new bacterial proteins. This inducible event appears to be a coordinately regulated system dependent on trypsin- and neuraminidase-sensitive structures present on the epithelial cell surface. Mutants of S. choleraesuis and S. typhimurium were unable to synthesize these proteins and did not stably adhere to nor invade eukaryotic cells. Two such S. typhimurium mutants were avirulent in mice, an indication that these proteins are required for Salmonella virulence.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Finlay, B B -- Heffron, F -- Falkow, S -- AI26195/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 1989 Feb 17;243(4893):940-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medical Microbiology, Stanford University School of Medicine, CA 94305.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2919285" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Bacterial Adhesion ; Bacterial Proteins/*biosynthesis ; Cell Line ; Epithelium/physiology ; Kinetics ; Methionine/metabolism ; Salmonella/pathogenicity/*physiology ; Sulfur Radioisotopes
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-12-22
    Description: Analysis of crosslinked complexes of M1 RNA, the catalytic RNA subunit of ribonuclease P from Escherichia coli, and transfer RNA precursor substrates has led to the identification of regions in the enzyme and in the substrate that are in close physical proximity to each other. The nucleotide in M1 RNA, residue C92, which participates in a crosslink with the substrate was deleted and the resulting mutant M1 RNA was shown to cleave substrates lacking the 3' terminal CCAUCA sequence at sites several nucleotides away from the normal site of cleavage. The presence or absence of the 3' terminal CCAUCA sequence in transfer RNA precursor substrates markedly affects the way in which these substrates interact with the catalytic RNA in the enzyme-substrate complex. The contacts between wild-type M1 RNA and its substrate are in a region that resembles part of the transfer RNA "E" (exit) site in 23S ribosomal RNA. These data demonstrate that in RNA's with very different cellular functions, there are domains with similar structural and functional properties and that there is a nucleotide in M1 RNA that affects the site of cleavage by the enzyme.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Guerrier-Takada, C -- Lumelsky, N -- Altman, S -- New York, N.Y. -- Science. 1989 Dec 22;246(4937):1578-84.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, Yale University, New Haven, CT 06520.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2480641" target="_blank"〉PubMed〈/a〉
    Keywords: Base Sequence ; Endoribonucleases/genetics/*metabolism ; Escherichia coli/enzymology/*genetics ; *Escherichia coli Proteins ; Kinetics ; Molecular Sequence Data ; Nucleic Acid Conformation ; RNA Precursors/genetics ; RNA, Bacterial/*genetics/metabolism ; RNA, Transfer/genetics ; Ribonuclease P ; Substrate Specificity
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Publication Date: 1989-05-12
    Description: The intervening sequence of the ribosomal RNA precursor of Tetrahymena is a catalytic RNA molecule, or ribozyme. Acting as a sequence-specific endoribonuclease, it cleaves single-stranded RNA substrates with concomitant addition of guanosine. The chemistry of the reaction has now been studied by introduction of a single phosphorothioate in the substrate RNA at the cleavage site. Kinetic studies show no significant effect of this substitution on kcat (rate constant) or Km (Michaelis constant), providing evidence that some step other than the chemical step is rate-limiting. Product analysis reveals that the reaction proceeds with inversion of configuration at phosphorus, consistent with an in-line, SN2 (P) mechanism. Thus, the ribozyme reaction is in the same mechanistic category as the individual displacement reactions catalyzed by protein nucleotidyltransferases, phosphotransferases, and nucleases.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McSwiggen, J A -- Cech, T R -- GM28039/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1989 May 12;244(4905):679-83.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309-0215.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2470150" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Base Sequence ; Guanosine/metabolism ; Hydrolysis ; Kinetics ; Molecular Conformation ; Phosphates/metabolism ; Phosphorus ; RNA/*metabolism ; RNA Precursors/*metabolism ; RNA Splicing ; RNA, Catalytic ; RNA, Ribosomal/*metabolism ; Tetrahymena/*genetics ; Thionucleotides/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-06-02
    Description: Double-stranded (ds) RNA and many viruses are inducers of interferon (IFN), the latter presumably because they contain, or can form, dsRNA. Concomitant with the induction of IFN in chicken embryo cells was the induction of a novel double-stranded ribonuclease (dsRNase), which was released into the medium and continued to accumulate long after IFN production ceased. Only avian cells (chicken, quail, turkey, or duck) expressed high levels of this dsRNase; mammalian, turtle, or fish cells did not. Production of the nuclease was inducer dose-dependent. Optimum pH and cation requirements distinguished it from other dsRNase activities. Degradation of dsRNA was endonucleolytic. Activity resided in a molecule of an Mr of approximately 34,500. Low levels of a single-stranded (ss) RNase activity were inseparable from the dsRNase. The role for a dsRNA-inducible dsRNase released from cells is unknown.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Meegan, J M -- Marcus, P I -- AI18381/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 1989 Jun 2;244(4908):1089-91.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cell Biology, The University of Connecticut, Storrs 06269.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2471268" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Birds/embryology/*metabolism ; Cations ; Chick Embryo ; Ducks/embryology ; Endoribonucleases/*biosynthesis ; Enzyme Induction ; Hydrogen-Ion Concentration ; Interferon Inducers/pharmacology ; Interferons/*metabolism ; Kinetics ; Newcastle disease virus/physiology/radiation effects ; Poly I-C/pharmacology ; Quail/embryology ; RNA, Double-Stranded/metabolism ; Species Specificity ; Substrate Specificity ; Turkeys/embryology ; Ultraviolet Rays
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Publication Date: 1989-05-12
    Description: Methotrexate coupled to maleylated bovine serum albumin was taken up efficiently through the "scavenger" receptors present on macrophages and led to selective killing of intracellular Leishmania mexicana amazonensis amastigotes in cultured hamster peritoneal macrophages. The drug conjugate was nearly 100 times as effective as free methotrexate in eliminating the intracellular parasites. Furthermore, in a model of experimental cutaneous leishmaniasis in hamsters, the drug conjugate brought about more than 90% reduction in the size of footpad lesions within 11 days. In contrast, the free drug at a similar concentration did not significantly affect lesion size. These studies demonstrate the potential of receptor-mediated drug delivery in the therapy of macrophage-associated diseases.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mukhopadhyay, A -- Chaudhuri, G -- Arora, S K -- Sehgal, S -- Basu, S K -- New York, N.Y. -- Science. 1989 May 12;244(4905):705-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Microbial Technology, Chandigarh, India.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2717947" target="_blank"〉PubMed〈/a〉
    Keywords: Albumins/*administration & dosage/metabolism ; Animals ; Cells, Cultured ; Cricetinae ; Female ; Kinetics ; Leishmania mexicana/*drug effects ; Leishmaniasis/*drug therapy ; Macrophages/metabolism/*parasitology ; Male ; *Membrane Proteins ; Mesocricetus ; Methotrexate/*administration & dosage/pharmacology/therapeutic use ; *Receptors, Immunologic/metabolism ; *Receptors, Lipoprotein ; Receptors, Scavenger ; Scavenger Receptors, Class B ; Serum Albumin, Bovine
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-12-22
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schwarz, S -- Pohl, P -- Zhou, G Z -- New York, N.Y. -- Science. 1989 Dec 22;246(4937):1635-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2556797" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Binding, Competitive ; Brain/metabolism ; Kinetics ; Ligands ; Lymphocytes/metabolism ; Progesterone/blood/cerebrospinal fluid/metabolism ; Receptors, Opioid/*metabolism ; Receptors, sigma ; Steroids/*metabolism/pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-10-06
    Description: A microscopic method for simulating quantum mechanical, nuclear tunneling effects in biological electron transfer reactions is presented and applied to several electron transfer steps in photosynthetic bacterial reaction centers. In this "dispersed polaron" method the fluctuations of the protein and the electron carriers are projected as effective normal modes onto an appropriate reaction coordinate and used to evaluate the quantum mechanical rate constant. The simulations, based on the crystallographic structure of the reaction center from Rhodopseudomonas viridis, focus on electron transfer from a bacteriopheophytin to a quinone and the subsequent back-reaction. The rates of both of these reactions are almost independent of temperature or even increase with decreasing temperature. The simulations reproduce this unusual temperature dependence in a qualitative way, without the use of adjustable parameters for the protein's Franck-Condon factors. The observed dependence of the back-reaction on the free energy of the reaction also is reproduced, including the special behavior in the "inverted region."〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Warshel, A -- Chu, Z T -- Parson, W W -- GM-40283/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1989 Oct 6;246(4926):112-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, University of Southern California, Los Angeles 90007.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2675313" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/*metabolism ; *Electron Transport ; Kinetics ; Models, Chemical ; *Photosynthesis ; Photosynthetic Reaction Center Complex Proteins ; Rhodopseudomonas/metabolism ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-03-17
    Description: A true Bronsted analysis of proton transfer in an enzyme mechanism is made possible by the chemical rescue of an inactive mutant of aspartate aminotransferase, where the endogenous general base, Lys258, is replaced with Ala by site-directed mutagenesis. Catalytic activity is restored to this inactive mutant by exogenous amines. The eleven amines studied generate a Bronsted correlation with beta of 0.4 for the transamination of cysteine sulfinate, when steric effects are included in the regression analysis. Localized mutagenesis thus allows the classical Bronsted analysis of transition-state structure to be applied to enzyme-catalyzed reactions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Toney, M D -- Kirsch, J F -- GM07232/GM/NIGMS NIH HHS/ -- GM35393/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1989 Mar 17;243(4897):1485-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of California, Berkeley 94720.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2538921" target="_blank"〉PubMed〈/a〉
    Keywords: Amines ; Aspartate Aminotransferases/*metabolism ; Binding Sites ; Catalysis ; Escherichia coli/enzymology ; Kinetics ; Lysine ; Mutation ; Protons
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-02-24
    Description: Gadolinium ions produce three distinct kinds of block of the stretch-activated (SA) ion channels in Xenopus oocytes: a concentration-dependent reduction in channel open time, a concentration-dependent reduction in open channel current, and a unique, steeply concentration-dependent, reversible inhibition of channel opening. This last effect reduces the probability of a channel being open from about 10(-1) at 5 microM to less than 10(-5) at 10 microM gadolinium. Calcium has effects on open time and current similar to that of gadolinium, but this channel is permeable to calcium and calcium does not completely inhibit channel activity. The availability of a blocker for SA ion channels may help to define their physiological function, and will simplify the use of oocytes as an expression system for ion channels.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yang, X C -- Sachs, F -- DK-37792/DK/NIDDK NIH HHS/ -- New York, N.Y. -- Science. 1989 Feb 24;243(4894 Pt 1):1068-71.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉State University of New York, Buffalo 14214.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2466333" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Binding, Competitive ; Calcium/*pharmacology ; Cations ; Electric Conductivity ; Female ; Gadolinium/*pharmacology ; Ion Channels/drug effects/*physiology ; Kinetics ; Oocytes/*physiology ; Xenopus
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-07-07
    Description: beta-Adrenergic agonists activate the G protein, Gs, which stimulates cardiac calcium currents by both cytoplasmic, indirect and membrane-delimited, direct pathways. To test whether beta-adrenergic agonists might use both pathways in the heart, isoproterenol was rapidly applied to cardiac myocytes, resulting in a biphasic increase in cardiac calcium channel currents that had time constants of 150 milliseconds and 36 seconds. beta-Adrenergic antagonists of a G protein inhibitor blocked both the fast and slow responses, whereas the adenylyl cyclase activator forskolin produced only the slow response. The presence of a fast pathway in the heart can explain what the slow pathway cannot account for: the ability of cardiac sympathetic nerves to change heart rate within a single beat.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yatani, A -- Brown, A M -- HL36930/HL/NHLBI NIH HHS/ -- HL37044/HL/NHLBI NIH HHS/ -- NS23877/NS/NINDS NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1989 Jul 7;245(4913):71-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2544999" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Atrial Function ; Calcium Channels/drug effects/*physiology ; Carbachol/pharmacology ; Cells, Cultured ; Colforsin/pharmacology ; GTP-Binding Proteins/*physiology ; Guinea Pigs ; Heart/*physiology ; Isoproterenol/*pharmacology ; Kinetics ; Membrane Potentials/drug effects ; *Signal Transduction
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Publication Date: 1989-11-03
    Description: Many Gram-negative bacteria export proteins to the exterior. Some of these proteins are first secreted into the periplasm and then cross the outer membrane in a separate step. The source of energy required for the translocation is unknown. Export of the extracellular protein proaerolysin from the periplasm through the outer membrane of Aeromonas salmonicida is inhibited by a proton ionophore and by low extracellular pH. One possible explanation of these results is that a proton gradient across the outer membrane is required for export.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wong, K R -- Buckley, J T -- New York, N.Y. -- Science. 1989 Nov 3;246(4930):654-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Microbiology, University of Victoria, BC, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2814486" target="_blank"〉PubMed〈/a〉
    Keywords: Aeromonas/drug effects/*metabolism ; Bacterial Toxins/*metabolism ; Carbonyl Cyanide m-Chlorophenyl Hydrazone/pharmacology ; Cell Membrane/metabolism ; Culture Media ; Hemolysin Proteins/*metabolism ; Hydrogen-Ion Concentration ; Kinetics ; Pore Forming Cytotoxic Proteins
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1988-12-16
    Description: The expression of a laboratory strain of HIV-1 (HTLV-IIIB) has been studied in mitogen-stimulated peripheral blood lymphocytes (PBLs) and in two lymphoid cell lines (CEM cells and C8166 cells). HIV-expressing cells contained from 300,000 to 2,500,000 copies of viral RNA per cell. Near-synchronous expression of an active infection could be achieved in C8166 cells. In these cells, the high copy numbers of viral RNA used as much as 40% of total protein synthesis for the production of viral gag protein, with high levels of viral RNA and protein synthesis preceding cell death by 2 to 4 days.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Somasundaran, M -- Robinson, H L -- AI 24474/AI/NIAID NIH HHS/ -- N01-HB-6-7022/HB/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1988 Dec 16;242(4885):1554-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pathology, University of Massachusetts Medical Center, Worcester 01655.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3201245" target="_blank"〉PubMed〈/a〉
    Keywords: Cell Line ; *Cell Transformation, Viral ; HIV-1/*genetics/growth & development/metabolism ; Humans ; Kinetics ; Lymphocytes/*microbiology ; RNA, Viral/*biosynthesis ; Viral Proteins/*biosynthesis
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Publication Date: 1988-03-18
    Description: The effects of lithium on inositol phosphate metabolism may account for the therapeutic actions of lithium in affective disorder. Muscarinic stimulation of the phosphoinositide system blocks synaptic inhibitory actions of adenosine in the hippocampal slice. At therapeutic concentrations, lithium diminished this muscarinic response, whereas rubidium, which does not affect phosphoinositide metabolism, had no effect. A dampening of phosphoinositide-mediated neurotransmission may explain the normalizing effects of lithium in treating both mania and depression.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Worley, P F -- Heller, W A -- Snyder, S H -- Baraban, J M -- DA-00266/DA/NIDA NIH HHS/ -- MH-18501/MH/NIMH NIH HHS/ -- MH-42323/MH/NIMH NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1988 Mar 18;239(4846):1428-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2831626" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine/pharmacology ; Carbachol/pharmacology ; Enzyme Activation/drug effects ; Hippocampus/drug effects/*physiology ; Inositol Phosphates/metabolism ; Kinetics ; Lithium/*pharmacology ; Oxotremorine/analogs & derivatives/pharmacology ; Phorbol Esters/pharmacology ; Phosphatidylinositols/*metabolism ; Protein Kinase C/metabolism ; Receptors, Muscarinic/drug effects/*physiology ; Synapses/physiology ; Synaptic Transmission/drug effects
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1988-06-24
    Description: A specific, reversible binding site for a free amino acid is detectable on the intron of the Tetrahymena self-splicing ribosomal precursor RNA. The site selects arginine among the natural amino acids, and prefers the L- to the D-amino acid. The dissociation constant is in the millimolar range, and amino acid binding is at or in the catalytic rG splicing substrate site. Occupation of the G site by L-arginine therefore inhibits splicing by inhibiting the binding of rG, without inhibition of later reactions in the splicing reaction sequence. Arginine binding specificity seems to be directed at the side chain and the guanidino radical, and the alpha-amino and carboxyl groups are dispensable for binding. The arginine site can be placed within the G site by structural homology, with consequent implications for RNA-amino acid interaction, for the origin of the genetic code, for control of RNA activities, and for further catalytic capabilities for RNA.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yarus, M -- R37 GM30881/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1988 Jun 24;240(4860):1751-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder 80309.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3381099" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Arginine/*metabolism ; Binding Sites ; Catalysis ; Genetic Code ; Guanosine Triphosphate/metabolism ; Kinetics ; Magnesium/metabolism ; Models, Molecular ; *RNA Splicing ; RNA, Ribosomal/*physiology ; Structure-Activity Relationship ; Tetrahymena
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1988-02-12
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zeeberg, B R -- Gibson, R E -- Reba, R C -- MH42821-01/MH/NIMH NIH HHS/ -- NS-15080/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1988 Feb 12;239(4841 Pt 1):789-91.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2963379" target="_blank"〉PubMed〈/a〉
    Keywords: Brain/*metabolism ; Haloperidol/therapeutic use ; Humans ; Kinetics ; Receptors, Dopamine/drug effects/*metabolism ; Receptors, Dopamine D2 ; Schizophrenia/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Publication Date: 1989-05-26
    Description: The eye needs to biosynthesize 11-cis-retinoids because the chromophore of rhodopsin is 11-cis-retinal. The critical metabolic step is the endergonic isomerization of free all-trans-retinol (vitamin A) into 11-cis-retinol. This isomerization process can take place in isolated membranes from the retinal pigment epithelium in the absence of added energy sources. Specific binding proteins probably do not serve as an energy source, and since all of the reactions in the visual cycle are shown here to be reversible, trapping reactions also do not participate in the isomerization reaction. One previously unexplored possibility is that the chemical energy in the bonds of the membrane itself may drive the isomerization reaction. A group transfer reaction is proposed that forms a retinyl ester from a lipid acyl donor and vitamin A. This transfer can drive the isomerization reaction because the all-trans-retinyl ester is isomerized directly to 11-cis-retinol. Thus, the free energy of hydrolysis of the ester is coupled to the thermodynamically uphill trans to cis isomerization. The prediction of an obligate C-O bond cleavage in the vitamin A moiety during isomerization is borne out. Although the natural substrate for isomerization is not known, all-trans-retinyl palmitate is processed in vitro to 11-cis-retinol by pigment epithelial membranes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Deigner, P S -- Law, W C -- Canada, F J -- Rando, R R -- EY04096/EY/NEI NIH HHS/ -- New York, N.Y. -- Science. 1989 May 26;244(4907):968-71.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2727688" target="_blank"〉PubMed〈/a〉
    Keywords: Amphibians ; Animals ; Cattle ; Cell Membrane/*metabolism ; *Energy Metabolism ; Isomerases/metabolism ; Isomerism ; Kinetics ; Molecular Structure ; Pigment Epithelium of Eye/*metabolism/radiation effects ; Ultraviolet Rays ; Vitamin A/analogs & derivatives/*metabolism ; *cis-trans-Isomerases
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-01-13
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Catterall, W A -- New York, N.Y. -- Science. 1989 Jan 13;243(4888):236-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2536189" target="_blank"〉PubMed〈/a〉
    Keywords: Kinetics ; Ligands ; Receptors, Adrenergic, alpha/*metabolism ; Receptors, Adrenergic, beta/*metabolism ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-03-10
    Description: Primary and secondary protium-to-tritium (H/T) and deuterium-to-tritium (D/T) kinetic isotope effects for the catalytic oxidation of benzyl alcohol to benzaldehyde by yeast alcohol dehydrogenase (YADH) at 25 degrees Celsius have been determined. Previous studies showed that this reaction is nearly or fully rate limited by the hydrogen-transfer step. Semiclassical mass considerations that do not include tunneling effects would predict that kH/kT = (kD/kT)3.26, where kH, kD, and kT are the rate constants for the reaction of protium, deuterium, and tritium derivatives, respectively. Significant deviations from this relation have now been observed for both primary and especially secondary effects, such that experimental H/T ratios are much greater than those calculated from the above expression. These deviations also hold in the temperature range from 0 to 40 degrees Celsius. Such deviations were previously predicted to result from a reaction coordinate containing a significant contribution from hydrogen tunneling.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cha, Y -- Murray, C J -- Klinman, J P -- New York, N.Y. -- Science. 1989 Mar 10;243(4896):1325-30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, University of California, Berkeley 94720.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2646716" target="_blank"〉PubMed〈/a〉
    Keywords: Alcohol Dehydrogenase/*metabolism ; Benzyl Alcohols ; *Hydrogen ; Kinetics ; Mathematics ; Models, Theoretical ; Oxidation-Reduction ; Saccharomyces cerevisiae/enzymology ; Thermodynamics ; Tritium
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Publication Date: 1988-02-05
    Description: The turnover of phosphatidylinositol 4,5-bisphosphate (PIP2) is believed to constitute a crucial step in the signaling pathways for stimulation of cells by a variety of bioactive substances, including mitogens, but decisive evidence for the idea has not been obtained. In the present study, a monoclonal antibody to PIP2 was microinjected into the cytoplasm of NIH 3T3 cells before or after exposure to mitogens. The antibody completely abolished nuclear labeling with [3H]thymidine induced by platelet-derived growth factor and bombesin, but not by fibroblast growth factor, epidermal growth factor, insulin, or serum. The findings strongly suggest that PIP2 breakdown is crucial in the elicitation and sustaining of cell proliferation induced by some types of mitogens such as platelet-derived growth factor and bombesin.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Matuoka, K -- Fukami, K -- Nakanishi, O -- Kawai, S -- Takenawa, T -- New York, N.Y. -- Science. 1988 Feb 5;239(4840):640-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, Tokyo Metropolitan Institute of Gerontology, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2829356" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Antibodies, Monoclonal ; Antigen-Antibody Complex ; Bombesin/*pharmacology ; Cell Division/*drug effects ; Cells, Cultured ; Insulin/pharmacology ; Kinetics ; Mice ; Mice, Inbred Strains ; Phosphatidylinositol 4,5-Diphosphate ; Phosphatidylinositols/immunology/*physiology ; Platelet-Derived Growth Factor/*pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Publication Date: 1988-02-26
    Description: Leader peptides that function to direct export of proteins through membranes have some common features but exhibit a remarkable sequence diversity. Thus there is some question whether leader peptides exert their function through conventional stereospecific protein-protein interaction. Here it is shown that the leader peptides retarded the folding of precursor maltose-binding protein and ribose-binding protein from Escherichia coli. This kinetic effect may be crucial in allowing precursors to enter the export pathway.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Park, S -- Liu, G -- Topping, T B -- Cover, W H -- Randall, L L -- GM29798/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1988 Feb 26;239(4843):1033-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Biochemistry/Biophysics Program, Washington State University, Pullman 99164.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3278378" target="_blank"〉PubMed〈/a〉
    Keywords: *ATP-Binding Cassette Transporters ; Bacterial Proteins/*metabolism ; Biological Transport ; Carrier Proteins/metabolism ; Endopeptidase K ; Escherichia coli/*metabolism ; *Escherichia coli Proteins ; Guanidine ; Guanidines/pharmacology ; Kinetics ; Maltose-Binding Proteins ; *Monosaccharide Transport Proteins ; Peptide Hydrolases ; *Periplasmic Binding Proteins ; *Protein Conformation/drug effects ; Protein Denaturation ; Protein Precursors/*metabolism ; Protein Sorting Signals/pharmacology/*physiology ; Serine Endopeptidases/pharmacology ; Spectrometry, Fluorescence
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Publication Date: 1988-10-14
    Description: Suspensions of thymocytes from young rats were incubated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which resulted in a sustained increase in cytosolic free Ca2+ concentration followed by DNA fragmentation and loss of cell viability. Both the Ca2+ increase and DNA fragmentation were prevented in cells treated with the inhibitor of protein synthesis, cycloheximide, and DNA fragmentation and cell killing were not detected when cells were incubated in a "Ca2+-free" medium or pretreated with high concentrations of the calcium probe, quin-2 tetraacetoxymethyl ester. These results indicate that TCDD can kill immature thymocytes by initiating a suicide process similar to that previously described for glucocorticoid hormones.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McConkey, D J -- Hartzell, P -- Duddy, S K -- Hakansson, H -- Orrenius, S -- New York, N.Y. -- Science. 1988 Oct 14;242(4876):256-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Toxicology, Karolinska Institutet, Stockholm, Sweden.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3262923" target="_blank"〉PubMed〈/a〉
    Keywords: Aminoquinolines ; Animals ; Calcium/metabolism/*pharmacology ; Cell Survival/drug effects ; Cycloheximide/pharmacology ; Cytosol/metabolism ; DNA/metabolism ; Deoxyribonuclease I/*metabolism ; Dioxins/*pharmacology ; Enzyme Activation/drug effects ; Fluorescent Dyes ; Glucocorticoids/pharmacology ; Kinetics ; Rats ; T-Lymphocytes/drug effects ; Tetrachlorodibenzodioxin/*pharmacology ; Thymus Gland/*drug effects/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1988-04-29
    Description: The kinetics of calcium release by inositol 1,4,5-trisphosphate (IP3) in permeabilized rat basophilic leukemia cells were studied to obtain insight into the molecular mechanism of action of this intracellular messenger of the phosphoinositide cascade. Calcium release from intracellular storage sites was monitored with fura-2, a fluorescent indicator. The dependence of the rate of calcium release on the concentration of added IP3 in the 4 to 40 nM range showed that channel opening requires the binding of at least three molecules of IP3. Channel opening occurred in the absence of added adenosine triphosphate, indicating that IP3 acts directly on the channel or on a protein that gates it. The channels were opened by IP3 in less than 4 seconds. The highly cooperative opening of calcium channels by nanomolar concentrations of IP3 enables cells to detect and amplify very small changes in the concentration of this messenger in response to hormonal, sensory, and growth control stimuli.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Meyer, T -- Holowka, D -- Stryer, L -- AI22449/AI/NIAID NIH HHS/ -- GM24032/GM/NIGMS NIH HHS/ -- GM30387/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1988 Apr 29;240(4852):653-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell Biology, Sherman Fairchild Center, Stanford University School of Medicine, CA 94305.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2452482" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Basophils ; Benzofurans ; Calcimycin/pharmacology ; Calcium/*metabolism ; Cell Membrane Permeability ; Cytoplasm/metabolism ; Fluorescent Dyes ; Fura-2 ; Inositol 1,4,5-Trisphosphate ; Inositol Phosphates/metabolism/*pharmacology ; Ion Channels/drug effects/*metabolism ; Kinetics ; Leukemia, Experimental/metabolism ; Rats ; Spectrometry, Fluorescence ; Sugar Phosphates/*pharmacology ; Tumor Cells, Cultured
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Publication Date: 1988-10-21
    Description: Studies of the biology and pathogenesis of Kaposi's sarcoma (KS) have been hampered by the inability to maintain long-term cultures of KS cells in vitro. In this study AIDS-KS-derived cells with characteristic spindle-like morphology were cultured with a growth factor (or factors) released by CD4+ T lymphocytes infected with human T-lymphotropic virus type I or II (HTLV-I or HTLV-II) or with human immunodeficiency virus type 1 or 2 (HIV-1 or HIV-2). Medium conditioned by HTLV-II-infected, transformed lines of T cells (HTLV-II CM) contained large amounts of this growth activity and also supported the temporary growth of normal vascular endothelial cells, but not fibroblasts. Interleukin-1 and tumor necrosis factor-alpha stimulated the growth of the KS-derived cells, but the growth was only transient and these could be distinguished from that in HTLV-II CM. Other known endothelial cell growth promoting factors, such as acidic and basic fibroblast growth factors and epidermal growth factor, did not support the long-term growth of the AIDS-KS cells. The factor released by CD4+ T cells infected with human retroviruses should prove useful in studies of the pathogenesis of KS.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nakamura, S -- Salahuddin, S Z -- Biberfeld, P -- Ensoli, B -- Markham, P D -- Wong-Staal, F -- Gallo, R C -- New York, N.Y. -- Science. 1988 Oct 21;242(4877):426-30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Tumor Cell Biology, National Cancer Institute, Bethesda, MD 20892.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3262925" target="_blank"〉PubMed〈/a〉
    Keywords: Acquired Immunodeficiency Syndrome/immunology/*pathology ; Antigens, Differentiation, T-Lymphocyte/analysis ; Cell Division ; *Cell Transformation, Viral ; Growth Substances/*isolation & purification/physiology ; Human T-lymphotropic virus 1/*genetics ; Human T-lymphotropic virus 2/*genetics ; Humans ; Kinetics ; Sarcoma, Kaposi/*pathology ; T-Lymphocytes/*immunology ; Tumor Cells, Cultured
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Publication Date: 1988-11-11
    Description: Despite its potential toxicity, H2O2 is used as an extracellular oxidant by Stronglylocentrotus purpuratus eggs to cross-link their fertilization envelopes. These eggs contain 5 mM 1-methyl-N alpha,N alpha-dimethyl-4-mercaptohistidine (ovothiol C), which reacts with H2O2. In consuming H2O2 and being reduced by glutathione, ovothiol acts as a glutathione peroxidase and replaces the function of the enzyme in eggs. The ovothiol system is more effective than egg catalase in destroying H2O2 at concentrations produced during fertilization and constitutes a principal mechanism for preventing oxidative damage at fertilization.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Turner, E -- Hager, L J -- Shapiro, B M -- GM23910/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1988 Nov 11;242(4880):939-41.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Washington, Seattle 98195.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3187533" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acids, Sulfur/*metabolism ; Animals ; Catalase/metabolism ; Disulfides/metabolism ; Female ; Fertilization ; Glutathione/metabolism ; Glutathione Peroxidase/*metabolism ; Kinetics ; *Methylhistidines ; NADP/metabolism ; Ovum/*metabolism ; Oxidation-Reduction ; Sea Urchins
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Publication Date: 1988-12-16
    Description: Three variations to the structure of the nicotinamide adenine dinucleotide (NAD)-dependent L-lactate dehydrogenase from Bacillus stearothermophilus were made to try to change the substrate specificity from lactate to malate: Asp197----Asn, Thr246----Gly, and Gln102----Arg). Each modification shifts the specificity from lactate to malate, although only the last (Gln102----Arg) provides an effective and highly specific catalyst for the new substrate. This synthetic enzyme has a ratio of catalytic rate (kcat) to Michaelis constant (Km) for oxaloacetate of 4.2 x 10(6)M-1 s-1, equal to that of native lactate dehydrogenase for its natural substrate, pyruvate, and a maximum velocity (250 s-1), which is double that reported for a natural malate dehydrogenase from B. stearothermophilus.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wilks, H M -- Hart, K W -- Feeney, R -- Dunn, C R -- Muirhead, H -- Chia, W N -- Barstow, D A -- Atkinson, T -- Clarke, A R -- Holbrook, J J -- New York, N.Y. -- Science. 1988 Dec 16;242(4885):1541-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Bristol, United Kingdom.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3201242" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Geobacillus stearothermophilus/*enzymology/genetics ; Kinetics ; L-Lactate Dehydrogenase/*genetics/metabolism ; Malate Dehydrogenase/*metabolism ; Models, Molecular ; Protein Conformation ; Substrate Specificity
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1988-10-07
    Description: In vitro autoradiography with 125I-labeled melatonin was used to examine melatonin binding sites in human hypothalamus. Specific 125I-labeled melatonin binding was localized to the suprachiasmatic nuclei, the site of a putative biological clock, and was not apparent in other hypothalamic regions. Specific 125I-labeled melatonin binding was consistently found in the suprachiasmatic nuclei of hypothalami from adults and fetuses. Densitometric analysis of competition experiments with varying concentrations of melatonin showed monophasic competition curves, with comparable half-maximal inhibition values for the suprachiasmatic nuclei of adults (150 picomolar) and fetuses (110 picomolar). Micromolar concentrations of the melatonin agonist 6-chloromelatonin completely inhibited specific 125I-labeled melatonin binding, whereas the same concentrations of serotonin and norepinephrine caused only a partial reduction in specific binding. The results suggest that putative melatonin receptors are located in a human biological clock.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Reppert, S M -- Weaver, D R -- Rivkees, S A -- Stopa, E G -- HD06976/HD/NICHD NIH HHS/ -- HD14427/HD/NICHD NIH HHS/ -- U10-HD22297/HD/NICHD NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1988 Oct 7;242(4875):78-81.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Developmental Chronobiology, Boston.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2845576" target="_blank"〉PubMed〈/a〉
    Keywords: Autoradiography ; Binding, Competitive ; *Biological Clocks ; Humans ; Hypothalamus/*metabolism ; Iodine Radioisotopes ; Kinetics ; Melatonin/*metabolism ; Optic Chiasm/metabolism ; Receptors, Melatonin ; Receptors, Neurotransmitter/*physiology ; Suprachiasmatic Nucleus/metabolism ; Supraoptic Nucleus/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Publication Date: 1988-08-12
    Description: Calcium channels are inactivated by voltage and intracellular calcium. To study the kinetics and the mechanism of calcium-induced inactivation of calcium channels, a "caged" calcium compound, dimethoxy-nitrophen was used to photo-release about 50 microM calcium ion within 0.2 millisecond in dorsal root ganglion neurons. When divalent cations were the charge carriers, intracellular photo-release of calcium inactivated the calcium channel with an invariant rate [time constant (tau) approximately equal to 7 milliseconds]. When the monovalent cation sodium was the charge carrier, photorelease of calcium inside or outside of the cell blocked the channel rapidly (tau approximately equal to 0.4 millisecond), but the block was greater from the external side. Thus the kinetics of calcium-induced calcium channel inactivation depends on the valency of the permeant cation. The data imply that calcium channels exist in either of two conformational states, the calcium- and sodium-permeant forms, or, alternatively, calcium-induced inactivation occurs at a site closely associated with the internal permeating site.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Morad, M -- Davies, N W -- Kaplan, J H -- Lux, H D -- R01 HL-16152/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1988 Aug 12;241(4867):842-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉University of Pennsylvania, Department of Physiology, Philadelphia 19104-6085.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2457253" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Calcium/*physiology/radiation effects ; Cells, Cultured ; Chickens ; Ganglia, Spinal/*physiology/radiation effects ; Ion Channels/*physiology ; Kinetics ; Neurons/*physiology/radiation effects ; Photolysis ; Sodium/metabolism ; *Ultraviolet Rays
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Publication Date: 1989-09-01
    Description: Human alpha- and beta-globin genes were separately fused downstream of two erythroid-specific deoxyribonuclease (DNase) I super-hypersensitive sites that are normally located 50 kilobases upstream of the human beta-globin gene. These two constructs were coinjected into fertilized mouse eggs, and expression was analyzed in transgenic animals that developed. Mice that had intact copies of the transgenes expressed high levels of correctly initiated human alpha- and beta-globin messenger RNA specifically in erythroid tissue. An authentic human hemoglobin was formed in adult erythrocytes that when purified had an oxygen equilibrium curve identical to the curve of native human hemoglobin A (Hb A). Thus, functional human hemoglobin can be synthesized in transgenic mice. This provides a foundation for production of mouse models of human hemoglobinopathies such as sickle cell disease.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Behringer, R R -- Ryan, T M -- Reilly, M P -- Asakura, T -- Palmiter, R D -- Brinster, R L -- Townes, T M -- HD-09172/HD/NICHD NIH HHS/ -- HL-35559/HL/NHLBI NIH HHS/ -- HL-38632/HL/NHLBI NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1989 Sep 1;245(4921):971-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Reproductive Physiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2772649" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Deoxyribonuclease I ; Female ; *Genes ; Globins/biosynthesis/*genetics ; Hemoglobins/biosynthesis/*genetics ; Humans ; Kinetics ; Mice ; Mice, Transgenic ; Oxyhemoglobins/metabolism ; RNA, Messenger/genetics ; Transcription, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Publication Date: 1988-11-11
    Description: Manganous superoxide dismutase (MnSOD) scavenges potentially toxic superoxide radicals produced in the mitochondria. Tumor necrosis factor-alpha (TNF-alpha) was found to induce the messenger RNA for MnSOD, but not the mRNAs for other antioxidant or mitochondrial enzymes tested. The increase in MnSOD mRNA occurred rapidly and was blocked by actinomycin D, but not by cycloheximide. Induction of MnSOD mRNA was also observed with TNF-beta, interleukin-1 alpha (IL-1 alpha), and IL-1 beta but not with other cytokines or agents tested. TNF-alpha induced MnSOD mRNA in all cell lines and normal cells examined in vitro and in various organs of mice in vivo. These effects of TNF-alpha and IL-1 on target cells may contribute to their reported protective activity against radiation as well as their ability to induce resistance to cell killing induced by the combination of TNF-alpha and cycloheximide.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wong, G H -- Goeddel, D V -- New York, N.Y. -- Science. 1988 Nov 11;242(4880):941-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, Genentech, San Francisco, CA 94080.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3263703" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Catalase/metabolism ; Cell Line ; Cycloheximide/pharmacology ; Dactinomycin/pharmacology ; Enzyme Induction/drug effects ; Humans ; Interleukin-1/pharmacology ; Kinetics ; Mice ; Mitochondria/enzymology ; RNA, Messenger/biosynthesis ; Rats ; Superoxide Dismutase/*biosynthesis/genetics/metabolism ; Tissue Distribution ; Tumor Necrosis Factor-alpha/*pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1989-06-30
    Description: High-resolution differential interference contrast microscopy and digital imaging of the fluorescent calcium indicator dye fura-2 were performed simultaneously in single rat salivary gland acinar cells to examine the effects of muscarinic stimulation on cell volume and cytoplasmic calcium concentration ([Ca2+]i). Agonist stimulation of fluid secretion is initially associated with a rapid tenfold increase in [Ca2+]i as well as a substantial cell shrinkage. Subsequent changes of cell volume in the continued presence of agonist are tightly coupled to dynamic levels of [Ca2+]i, even during [Ca2+]i oscillations. Experiments with Ca2+ chelators and ionophores showed that physiological elevations of [Ca2+]i are necessary and sufficient to cause changes in cell volume. The relation between [Ca2+]i and cell volume suggests that the latter reflects the secretory state of the acinar cell. Agonist-induced changes in [Ca2+]i, by modulating specific ion permeabilities, result in solute movement into or out of the cell. The resultant cell volume changes may be important in modulating salivary secretion.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Foskett, J K -- Melvin, J E -- New York, N.Y. -- Science. 1989 Jun 30;244(4912):1582-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Physiology Department, Armed Forces Radiobiology Research Institute, Bethesda, MD 20814.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2500708" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Benzofurans ; Calcium/*metabolism ; Carbachol/pharmacology ; Cell Membrane/physiology ; Chelating Agents ; Chlorides/metabolism ; Cytoplasm/metabolism ; Egtazic Acid/analogs & derivatives ; Ethers/pharmacology ; Fluorescent Dyes ; Fura-2 ; Ionomycin ; Ionophores ; Kinetics ; Potassium/metabolism ; Rats ; Saliva/*secretion ; Salivary Glands/*cytology/drug effects/physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Publication Date: 1980-03-28
    Description: When microbial strains compete for the same limiting nutrient in continuous culture, resource-based competition theory predicts that only one strain will survive and all others will die out. The surviving strain expected from theory will be the one with the smallest subsistence or "break-even" concentration of the limiting resource, a concentration defined by the J parameter. This prediction has been confirmed in the case of auxotrophic bacterial strains competing for limiting tryptophan. Because the value of J can be measured on the strains grown alone, the theory can predict the qualitative outcomes of mixed-growth competition in advance of actual competition.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hansen, S R -- Hubbell, S P -- New York, N.Y. -- Science. 1980 Mar 28;207(4438):1491-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6767274" target="_blank"〉PubMed〈/a〉
    Keywords: Bacteria/*growth & development ; Culture Media ; Drug Resistance, Microbial ; Escherichia coli/growth & development ; Kinetics ; Models, Theoretical ; Nalidixic Acid/pharmacology ; Nutritional Physiological Phenomena ; Pseudomonas aeruginosa/growth & development ; Tryptophan/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1980-02-15
    Description: Autoradiographic and biochemical analyses of the hearts of female rhesus monkeys and baboons indicate that atrial and ventricular myocardial cells contain androgen receptors. Although the specific effects of nuclear uptake and retention of androgen on the function of heart muscle cells are not known, the presence of this receptor suggests that sex steroid hormones may affect myocardial function directly and may explain some of the peculiar differences in heart disease between men and women.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McGill, H C Jr -- Anselmo, V C -- Buchanan, J M -- Sheridan, P J -- New York, N.Y. -- Science. 1980 Feb 15;207(4432):775-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6766222" target="_blank"〉PubMed〈/a〉
    Keywords: Androgens/*metabolism ; Animals ; Coronary Disease/*etiology ; Dihydrotestosterone/metabolism ; Estradiol/metabolism ; Female ; Haplorhini ; Kinetics ; Macaca mulatta ; Myocardium/*metabolism ; Papio ; Receptors, Androgen/*metabolism ; Receptors, Steroid/*metabolism ; Sex Factors
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Publication Date: 1980-07-25
    Description: Accurate measurements of intracellular calcium activities in salivary gland epithelial cells of the insect Phormia regina were obtained with microelectrodes in which N,N'-di(11-ethoxycarbonyl)undecyl-N,N'-4,5-tetramethyl-3,6-dioxaoctane diacid diamide wsa incorporated in a liquid membrane system. When calibrated in solutions approximating the ionic concentration of the cell interior, these microelectrodes gave rapid stable responses that were linear functions of the logarithm of calcium activities and were not affected by potassium, sodium and magnesium. Continuous monitoring of calcium activities during serotonin-induced saliva release provided direct evidence of hormonal influence on transmembrane calcium movement and spontaneous regulation of intracellular calcium by stimulated cells.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉O'Doherty, J -- Youmans, S J -- Armstrong, W M -- Stark, R J -- New York, N.Y. -- Science. 1980 Jul 25;209(4455):510-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7394518" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Biological Transport/drug effects ; Calcium/*metabolism ; Diptera/*metabolism ; Epithelium/metabolism ; Kinetics ; Magnesium/pharmacology ; Microelectrodes ; Salivary Glands/drug effects/*metabolism ; Serotonin/pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1980-11-21
    Description: The rate at which glucose enters nerve terminals in muscle was estimated indirectly by measuring changes in miniature end-plate potential frequency D-Glucose entered nerve terminals in muscles with a fast twitch more rapidly than it entered those with a slow twitch. This suggests that nerve terminals in fast- and slow-twitch muscles differ in their rate of metabolism.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pickett, J B -- New York, N.Y. -- Science. 1980 Nov 21;210(4472):927-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7434009" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Biological Transport ; Diaphragm/innervation ; Glucose/*metabolism ; Kinetics ; Membrane Potentials ; Nerve Endings/*metabolism ; Neuromuscular Junction/*metabolism ; Osmolar Concentration ; Rats
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Publication Date: 1980-08-22
    Description: The binding of [6-alanine]gonadotropin-releasing hormone to pituitary plasma membranes increased threefold between metestrus and early proestrus in female rats. Receptor numbers fell rapidly on the afternoon of proestrus coincident with the preovulatory gonadotropin surge. The numbers of receptors for gonadotropin-releasing hormone were positively correlated with concentrations of estradiol in serum; this pattern may be a necessary component of increased pituitary sensitivty to gonadotropin-releasing hormone observed during proestrus.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Savoy-Moore, R T -- Schwartz, N B -- Duncan, J A -- Marshall, J C -- New York, N.Y. -- Science. 1980 Aug 22;209(4459):942-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6250218" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cell Membrane/metabolism ; Estradiol/blood ; *Estrus ; Feedback ; Female ; Follicle Stimulating Hormone/blood ; Gonadotropin-Releasing Hormone/analogs & derivatives/*metabolism ; Kinetics ; Luteinizing Hormone/blood ; Pituitary Gland, Anterior/*metabolism ; Pregnancy ; Progesterone/blood ; Rats ; Receptors, Cell Surface/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Publication Date: 1981-07-31
    Description: Benzodiazepines inhibit Ca2+-calmodulin-stimulated membrane protein phosphorylation. The effects of the benzodiazepines on protein phosphorylation are stereospecific and produced by membrane-bound benzodiazepine. The potency of benzodiazepine kinase inhibition is correlated with the ability of the benzodiazepines to inhibit electric shock-induced convulsions. These findings provide evidence that some of the anticonvulsant and neuronal stabilizing effects of benzodiazepines may be modulated by the Ca2+-calmodulin protein kinase system and indicate that this calmodulin-kinase system represents an identifiable benzodiazepine receptor in brain that is distinquishable by several criteria from the previously described high affinity benzodiazepine receptor.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉DeLorenzo, R J -- Burdette, S -- Holderness, J -- NS 1352/NS/NINDS NIH HHS/ -- NSI-EA-1-K04-NS245/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1981 Jul 31;213(4507):546-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6264605" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Benzodiazepines/metabolism ; Brain/*enzymology ; Calcium/*pharmacology ; Calcium-Binding Proteins/*pharmacology ; Calmodulin/*pharmacology ; Cell Membrane/enzymology ; Chlordiazepoxide/*pharmacology ; Diazepam/*pharmacology ; Enzyme Activation ; Kinetics ; Molecular Weight ; Phosphorylation ; Protein Kinases/*metabolism ; Rats ; Receptors, Drug/metabolism ; Receptors, GABA-A
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1981-08-07
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Evans, C H -- Tew, W P -- New York, N.Y. -- Science. 1981 Aug 7;213(4508):653-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7256262" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Cations ; *Erbium ; Kinetics ; *Magnetics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1981-06-12
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gonzalez, M F -- Deutsch, J A -- New York, N.Y. -- Science. 1981 Jun 12;212(4500):1283-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7233218" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Feeding Behavior ; Kinetics ; Male ; Rats ; *Satiation ; *Satiety Response ; Stomach/*physiology ; *Vagotomy
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Publication Date: 1981-12-04
    Description: The persistence of synthetic herbicides such as 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and its release in massive amounts as a herbicide (Agent Orange) have created toxicological problems in many countries. In nature, 2,4,5-T is slowly degraded by cooxidation and is not utilized as a sole source of carbon and energy. The technique of plasmid-assisted molecular breeding has led to the development of bacterial strains capable of totally degrading 2,4,5-T by using it as their sole source of carbon at high concentrations (greater than 1 mg/ml). Spectrophotometry and gas chromatography reveal various intermediates during growth of the culture with 2,4,5-T.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kellogg, S T -- Chatterjee, D K -- Chakrabarty, A M -- New York, N.Y. -- Science. 1981 Dec 4;214(4525):1133-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7302584" target="_blank"〉PubMed〈/a〉
    Keywords: 2,4,5-Trichlorophenoxyacetic Acid/*metabolism ; Bacteria/*genetics/metabolism ; Biotransformation ; Cell Division ; Kinetics ; Nucleic Acid Hybridization ; *Plasmids
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Publication Date: 1981-06-05
    Description: Two divalent cation ionophores, A23187 and Ionomycin, which are selective for calcium, stimulated the resorption of fetal rat long bones in organ culture at 0.1 to 1 micromolar but not at higher concentrations. Both agents inhibited DNA synthesis at concentrations that stimulated resorption. These results might explain the differences in ionophore effects on bone previously reported, and they imply that cell replication is not required for osteoclast formation in fetal rat long bone cultures.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lorenzo, J A -- Raisz, L G -- AM 07290/AM/NIADDK NIH HHS/ -- AM 18063/AM/NIADDK NIH HHS/ -- New York, N.Y. -- Science. 1981 Jun 5;212(4499):1157-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6785885" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Anti-Bacterial Agents/*pharmacology ; Bone Resorption/*drug effects ; Bone and Bones/drug effects/*metabolism ; Calcimycin/*pharmacology ; Calcium/metabolism ; Calcium Radioisotopes ; Cells, Cultured ; DNA/*biosynthesis ; DNA Replication/*drug effects ; Ethers/pharmacology ; Fetus ; Ionomycin ; Ionophores/pharmacology ; Kinetics ; Mice ; Parathyroid Hormone/pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1981-07-31
    Description: A loss in the number of functional, sodium ion-dependent, high-affinity choline transport sites was observed in the cortex and hippocampus of mice given an intracerebroventricular injection of 65 nanomoles of AF64A (ethylcholine mustard aziridinium ion) 3 days earlier. Such an effect was not observed in the striatum. This effect of AF64A represents a long-term neurochemical deficit at cholinergic nerve terminals in some brain regions which can lead to a persistent deficiency in central cholinergic transmission. The AF64A-treated animal may thus be a model for certain psychiatric or neurological disorders that appear to involve central cholinergic hypofunction.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mantione, C R -- Fisher, A -- Hanin, I -- MH 26320/MH/NIMH NIH HHS/ -- MH/AG 34893/MH/NIMH NIH HHS/ -- New York, N.Y. -- Science. 1981 Jul 31;213(4507):579-80.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6894649" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Aziridines/*pharmacology ; Azirines/*pharmacology ; Biological Transport/drug effects ; Brain/drug effects/*metabolism ; Cerebral Cortex/metabolism ; Choline/*analogs & derivatives/*metabolism/pharmacology ; Corpus Striatum/metabolism ; Hippocampus/metabolism ; Kinetics ; Mice ; Sodium/pharmacology ; Synaptosomes/drug effects/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1981-07-31
    Description: During normal development of the hamster eye, there is a substantial loss of cells from the retinal ganglion cell layer in the first two postnatal weeks. If one eye is lost at birth, this cell death is reduced in the remaining eye. This may account for the increased ipsilateral projection from this eye to the thalamus and midbrain observed in these animals.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sengelaub, D R -- Finlay, B L -- New York, N.Y. -- Science. 1981 Jul 31;213(4507):573-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7244655" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Animals, Newborn ; Cell Survival ; Cricetinae ; Kinetics ; Neurons/*physiology ; Rats ; Retina/cytology/*physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1981-07-17
    Description: Bee venom and phospholipase A2 extracted from bee venom enhanced guanylate cyclase (E.C. 4.6.1.2) activity two- to threefold in rat liver, lung, heart, kidney, ileum, and cerebellum. Dose-response relationships revealed that bee venom at concentrations as low as 1 microgram per milliliter and phospholipase A2 at 1 microunit per milliliter caused a maximal enhancement of guanylate cyclase.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Vesely, D L -- New York, N.Y. -- Science. 1981 Jul 17;213(4505):359-60.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6113689" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Bee Venoms/*pharmacology ; Dose-Response Relationship, Drug ; Enzyme Activation ; Guanylate Cyclase/*metabolism ; Kinetics ; Organ Specificity ; Phospholipases/*pharmacology ; Phospholipases A/*pharmacology ; Phospholipases A2 ; Rats
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Publication Date: 1981-07-17
    Description: Guanosine triphosphate cyclohydrolase, the enzyme that is apparently rate-limiting in biopterin biosynthesis, is increased in adrenal cortex and medulla of rats treated with insulin or reserpine. Denervation and hypophysectomy block the increase in medullary and cortical enzyme activity, respectively, whereas cycloheximide presents the increase in both tissues. These results provide evidence for induction and regulation of guanosine triphosphate cyclohydrolase.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Viveros, O H -- Lee, C L -- Abou-Donia, M M -- Nixon, J C -- Nichol, C A -- New York, N.Y. -- Science. 1981 Jul 17;213(4505):349-50.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7017928" target="_blank"〉PubMed〈/a〉
    Keywords: Adrenal Cortex/drug effects/*enzymology ; Adrenal Glands/innervation ; Adrenal Medulla/drug effects/*enzymology ; Aminohydrolases/*metabolism ; Animals ; Biopterin/*biosynthesis ; Cycloheximide/pharmacology ; Denervation ; GTP Cyclohydrolase/*metabolism ; Hypophysectomy ; Insulin/pharmacology ; Kinetics ; Male ; Organ Specificity ; Pteridines/*biosynthesis ; Rats ; Reserpine/pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Publication Date: 1981-03-06
    Description: Kinetic analysis of the uptake of carbon-14-labeled oleate in a single-pass perfusion of rat liver and saturable and specific binding of iodine-125-labeled albumin to hepatocytes in suspension suggest the existence of a receptor for albumin on the liver cell surface. The putative receptor appears to mediate uptake of albumin-bound fatty acids by the cell and may account for the efficient hepatic extraction of many other substances tightly bound to albumin.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Weisiger, R -- Gollan, J -- Ockner, R -- AM-07007/AM/NIADDK NIH HHS/ -- AM-13328/AM/NIADDK NIH HHS/ -- AM-21899/AM/NIADDK NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1981 Mar 6;211(4486):1048-51.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6258226" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Biological Transport ; Fatty Acids/*metabolism ; Female ; Kinetics ; Liver/*metabolism ; Oleic Acids/metabolism ; Protein Binding ; Rats ; Receptors, Albumin ; Receptors, Cell Surface/*metabolism ; Serum Albumin/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Publication Date: 1981-07-24
    Description: Nalidixic acid and novobiocin inhibit the aminoacylation and pyrophosphate exchange activities of glycyl- and leucyl-transfer RNA synthetases from bakers' yeast. Similar types of inhibition are observed for both enzymes, suggesting similar mechanisms. The potency of these inhibitors is comparable to that observed for their inhibition of in vivo DNA synthesis in eukaryotic cells.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wright, H T -- Nurse, K C -- Goldstein, D J -- GM 07654/GM/NIGMS NIH HHS/ -- GM 23598/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1981 Jul 24;213(4506):455-6.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7017932" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acyl-tRNA Synthetases/*antagonists & inhibitors ; Glycine-tRNA Ligase/*antagonists & inhibitors ; Kinetics ; Leucine-tRNA Ligase/*antagonists & inhibitors ; Nalidixic Acid/*pharmacology ; Novobiocin/*pharmacology ; Oxolinic Acid/*pharmacology ; Saccharomyces cerevisiae/*enzymology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1981-07-31
    Description: An established line of mesenchymal cells from the human embryonic palate is highly sensitive to the stimulatory effect of epidermal growth factor on growth, labeled thymidine incorporation, and ornithine decarboxylase activity. The results suggest that epidermal growth factor may play a key role in development of various human embryonic and fetal tissues.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yoneda, T -- Pratt, R M -- New York, N.Y. -- Science. 1981 Jul 31;213(4507):563-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7017936" target="_blank"〉PubMed〈/a〉
    Keywords: Cell Division/drug effects ; Cell Line ; DNA Replication/drug effects ; Embryo, Mammalian ; Epidermal Growth Factor/*pharmacology ; Female ; Humans ; Insulin/pharmacology ; Kinetics ; Organ Specificity ; Ornithine Decarboxylase/metabolism ; Palate/drug effects/*physiology ; Peptides/*pharmacology ; Pregnancy
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-07-16
    Description: A method has been developed for the measurement of intracellular free calcium in mammalian cells. The calcium-sensitive photoprotein aequorin can be incorporated into isolated cells by hypo-osmotic treatment without altering the cell viability, permeability, or metabolism. Intracellular calcium activity (Cai2+) was monitored in a perfusion system. In monkey kidney cells (LLC-MK2), Cai2+ is approximately 57 nanomoles per liter. Changes in Cai2+ with time can also be followed: exposure of the cells to anaerobiosis or the calcium ionophore A23187 reversibly increases Cai2+. The method has also been successfully tested in rat hepatocytes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Borle, A B -- Snowdowne, K W -- New York, N.Y. -- Science. 1982 Jul 16;217(4556):252-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6806904" target="_blank"〉PubMed〈/a〉
    Keywords: *Aequorin ; Anaerobiosis ; Animals ; Calcimycin/pharmacology ; Calcium/*metabolism ; Cell Line ; Kidney/drug effects/*metabolism ; Kinetics ; *Luminescent Proteins ; Macaca mulatta
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Publication Date: 1982-06-11
    Description: Receptors that selectively bind micromolar concentrations of benzodiazepines are present in rat brain membrane. These micromolar receptors exhibit saturable, stereospecific binding, and the potency of benzodiazepine binding to these receptors is correlated with the ability of the benzodiazepines to inhibit maximum electric shock-induced convulsions. Benzodiazepine receptors with nanomolar affinity differ from the micromolar receptors in their binding, kinetic, and pharmacologic characteristics. The micromolar receptors also bind phenytoin, a non-benzodiazepine anticonvulsant. These results provide evidence for a distinct class of clinically relevant benzodiazepine receptors that may regulate neuronal excitability and anticonvulsant activity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bowling, A C -- DeLorenzo, R J -- NS 1352/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Jun 11;216(4551):1247-50.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6281893" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Benzodiazepines/*metabolism/pharmacology ; Benzodiazepinones/metabolism ; Brain/*metabolism ; Calmodulin/antagonists & inhibitors ; Diazepam/metabolism ; Kinetics ; Ligands ; Protein Kinase Inhibitors ; Rats ; Receptors, Drug/*metabolism ; Receptors, GABA-A ; Structure-Activity Relationship
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-11-05
    Description: Simple chemical catalysts have been designed to achieve some desirable features of enzymes. These novel catalysts are not proteins, but they may incorporate the typical enzyme catalytic groups and they achieve selectivity in their reactions by use of geometric control, as do enzymes. Catalysts that carry out geometrically controlled chlorinations of aromatic rings and steroids have been constructed. Other catalysts achieve the selective synthesis of amino acids, and still others imitate ribonuclease in detailed mechanism and hydrolyze RNA. Optimization of geometries has led to a rate acceleration of over 10(8) in one instance.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Breslow, R -- New York, N.Y. -- Science. 1982 Nov 5;218(4572):532-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7123255" target="_blank"〉PubMed〈/a〉
    Keywords: Catalysis ; Cyclodextrins ; *Enzymes ; Kinetics ; Models, Chemical ; Ribonucleases ; Structure-Activity Relationship ; Substrate Specificity ; Transaminases
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-03-12
    Description: Brief tetanic stimulation of the preganglionic nerves to the superior cervical ganglion enhances the postganglionic response to single preganglionic stimuli for 1 to 3 hours. This long-term potentiation of transmission through the ganglion is apparently not attributable to a persistent muscarinic action of the preganglionic neurotransmitter, acetylcholine, since neither the magnitude nor the time course of the phenomenon is reduced by atropine. The decay of long-term potentiation can be described by a first-order kinetic process with a mean time constant of 80 minutes. We conclude that long-term potentiation, once considered a unique property of the hippocampus, is in fact a more general feature of synaptic function. This form of synaptic memory may significantly influence information processing and control in other regions of the nervous system, including autonomic ganglia.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Brown, T H -- McAfee, D A -- 12116/PHS HHS/ -- NS 16576/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Mar 12;215(4538):1411-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6278593" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Ganglia, Sympathetic/*physiology ; Kinetics ; Learning/*physiology ; Neuronal Plasticity ; Rats ; Synapses/*physiology ; *Synaptic Transmission ; Time Factors
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Publication Date: 1982-10-01
    Description: Studies of isolated islets labeled with radioactive leucine show that glucose at a critical time "marks" islets in such a way as to cause preferential release of newly synthesized insulin. The preferential release of insulin from marked islets is relatively independent of subsequent secretagogues or rates of insulin secretion. Previous kinetic studies have indicated that the critical time at which marking occurs is after proinsulin biosynthesis but before the secretory event. Thus, secretory cells may regulate the diversion of newly synthesized material for immediate release as it is approaching or transiting the Golgi apparatus.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gold, G -- Gishizky, M L -- Grodsky, G M -- AM 01410/AM/NIADDK NIH HHS/ -- New York, N.Y. -- Science. 1982 Oct 1;218(4567):56-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6181562" target="_blank"〉PubMed〈/a〉
    Keywords: 1-Methyl-3-isobutylxanthine/pharmacology ; Animals ; Glucose/*pharmacology ; In Vitro Techniques ; Insulin/biosynthesis/*secretion ; Islets of Langerhans/drug effects/*secretion ; Kinetics ; Leucine ; Potassium/pharmacology ; Tolbutamide/pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Publication Date: 1982-10-01
    Description: Rats rotated to the left when 5'-N-ethylcarboxamide adenosine (NECA) was injected into the left caudate nucleus and apomorphine was administered subcutaneously. The combination of NECA and apomorphine was more potent than L-(phenylisopropyl)adenosine and apomorphine in eliciting rotation, suggesting the involvement of adenosine receptors of the Ra type. The response was reduced when 2',5'-dideoxyadenosine was injected along with NECA into the caudate nucleus or when theorphylline was given intraperitoneally. Higher doses of apomorphine elicited a self-mutilatory response after the injection of NECA into the caudate nucleus. These results suggest that adenosine may be involved in the modulation of dopaminergic function in the striatum.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Green, R D -- Proudfit, H K -- Yeung, S M -- New York, N.Y. -- Science. 1982 Oct 1;218(4567):58-61.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7123218" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine/administration & dosage/*analogs & derivatives/pharmacology ; Adenosine-5'-(N-ethylcarboxamide) ; Animals ; Apomorphine/pharmacology ; Caudate Nucleus/*physiology ; Corpus Striatum/*physiology ; Dopamine/*physiology ; Injections ; Kinetics ; Male ; Motor Activity/drug effects ; Rats ; Rats, Inbred Strains ; Rotation ; Vasodilator Agents/*pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Publication Date: 1982-01-01
    Description: Administration of the hepatic carcinogen aflatoxin B1 to experimental animals results in covalent binding to liver mitochondrial DNA at concentrations three to four times higher than nuclear DNA. The concentration of carcinogen adducts in mitochondrial DNA remains unchanged even after 24 hours, possible because of lack of excision repair. Similarly, mitochondrial transcription and translation remain inhibited up to 24 hours suggesting long-term effects of aflatoxin B1 on the mitochondrial genetic system.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Niranjan, B G -- Bhat, N K -- Avadhani, N G -- CA-22762/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1982 Jan 1;215(4528):73-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6797067" target="_blank"〉PubMed〈/a〉
    Keywords: Aflatoxin B1 ; Aflatoxins/*metabolism ; Animals ; DNA, Mitochondrial/*metabolism ; Kinetics ; Liver Neoplasms/*chemically induced/metabolism ; Male ; Mitochondria, Liver/*metabolism ; Neoplasms, Experimental/chemically induced ; Protein Biosynthesis/drug effects ; Rats ; Transcription, Genetic/drug effects
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Publication Date: 1982-08-27
    Description: A cavity was made in the brain (entorhinal cortex) of developing or adult rats, and a small piece of Gelfoam was emplaced to collect fluid secreted into the wound. The neuronotrophic activity of the fluid was assayed with sympathetic and parasympathetic neurons in culture. The results show that wounds in the brain of developing or adult rats stimulate the accumulation of neuronotrophic factors and that the activity of these factors increases over the first few days after infliction of the damage.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nieto-Sampedro, M -- Lewis, E R -- Cotman, C W -- Manthorpe, M -- Skaper, S D -- Barbin, G -- Longo, F M -- Varon, S -- AG-00538/AG/NIA NIH HHS/ -- MH-19691/MH/NIMH NIH HHS/ -- NS-16349/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Aug 27;217(4562):860-1.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7100931" target="_blank"〉PubMed〈/a〉
    Keywords: Adrenergic Fibers/physiology ; Animals ; Brain/*physiology ; Brain Injuries/*physiopathology ; Cell Survival/drug effects ; Cells, Cultured ; Cholinergic Fibers/physiology ; Kinetics ; Nerve Growth Factors/*metabolism/pharmacology ; *Nerve Regeneration ; Rats ; Rats, Inbred Strains ; Wound Healing
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Publication Date: 1982-03-05
    Description: Norethisterone (17 alpha-ethynyl-19-nortestosterone) is an effective irreversible inhibitor of estrogen synthetase (aromatase), the enzyme responsible for the conversion of androgens to estrogens, even at a 2 X 10(-6) molar concentration. This irreversible inactivation, which is directed toward the active site of aromatase and requires the cofactor-reduced nicotinamide adenine dinucleotide phosphate, is both time- and concentration-dependent. Ethisterone (17 alpha-ethynyltestosterone), in contrast, is not a suicide inhibitor of aromatase even at concentrations of 10(-4) molar.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Osawa, Y -- Yarborough, C -- HDO4945/HD/NICHD NIH HHS/ -- New York, N.Y. -- Science. 1982 Mar 5;215(4537):1249-51.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7058343" target="_blank"〉PubMed〈/a〉
    Keywords: *Aromatase Inhibitors ; Binding Sites/drug effects ; Contraceptives, Oral/*pharmacology ; Estrogens/*biosynthesis ; Female ; Humans ; Kinetics ; Microsomes/enzymology ; Norethindrone/*pharmacology ; Oxidoreductases/*antagonists & inhibitors ; Placenta/enzymology ; Pregnancy
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-11-12
    Description: Transfer RNA's are probably very strongly selected for translational efficiency. In this article, the argument is presented that the coding performance of the triplet anticodon is enhanced by selection of a matching anticodon loop and stem sequence. the anticodon plus these nearby sequence features (the extended anticodon) therefore contains more coding information than the anticodon alone and can perform more efficiently and accurately at the ribosome. This idea successfully accounts for the relative efficiencies of many transfer RNA's.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yarus, M -- New York, N.Y. -- Science. 1982 Nov 12;218(4573):646-52.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6753149" target="_blank"〉PubMed〈/a〉
    Keywords: Base Sequence ; Escherichia coli/genetics ; Kinetics ; Nucleic Acid Conformation ; *Protein Biosynthesis ; RNA, Transfer/*genetics ; Ribosomes/metabolism ; Structure-Activity Relationship ; Suppression, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1983-12-16
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉New York, N.Y. -- Science. 1983 Dec 16;222(4629):1251-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6648532" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Behavior, Animal/drug effects ; Flupenthixol/*pharmacology ; Hypothalamus/*drug effects ; Kinetics ; Rats ; *Reward ; Self Stimulation/*drug effects ; Thioxanthenes/*pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Publication Date: 1983-03-25
    Description: Microinfusions of rat prolactin into the dorsal midbrain of estrogen-treated, ovariectomized rats increased lordosis behavior. Midbrain microinfusions of antiserum to prolactin into rats displaying maximum lordosis had the opposite effect. The distribution of a prolactin-like substance in the brain was studied immunocytochemically. The results suggest that a hypothalamic neuronal system projecting to the midbrain contains a prolactin-like substance that plays a role in facilitating this behavior and therefore may mediate some of the effects of estrogen on the brain. These data, together with others from studies of the prolactin gene and its regulation, indicate that it may be possible to analyze a sequence of molecular events in the brain that facilitate a behavioral response.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Harlan, R E -- Shivers, B D -- Pfaff, D W -- HD-05585/HD/NICHD NIH HHS/ -- HD-05737/HD/NICHD NIH HHS/ -- New York, N.Y. -- Science. 1983 Mar 25;219(4591):1451-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6828874" target="_blank"〉PubMed〈/a〉
    Keywords: Adrenalectomy ; Animals ; Castration ; Cerebral Cortex/drug effects/*physiology ; Cosyntropin/pharmacology ; Estradiol/pharmacology ; Female ; Growth Hormone/pharmacology ; Immune Sera ; Kinetics ; Mesencephalon/*physiology ; Oxytocin/pharmacology ; Posture ; Prolactin/administration & dosage/*pharmacology ; Rats ; Sexual Behavior, Animal/*drug effects ; Vasopressins/pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Publication Date: 1983-12-23
    Description: Endotoxin-free thymosin fraction 5 elevated corticotropin, beta-endorphin, and cortisol in a dose- and time-dependent fashion when administered intravenously to prepubertal cynomolgus monkeys. Two synthetic component peptides of thymosin fraction 5 had no acute effects on pituitary function, suggesting that some other peptides in thymosin fraction 5 were responsible for its corticotropin-releasing activity. In agreement with these observations, total thymectomy of juvenile macaques was associated with decreases in plasma cortisol, corticotropin, and beta-endorphin. These findings indicate that the prepubertal primate thymus contains corticotropin-releasing activity that may contribute to a physiological immunoregulatory circuit between the developing immunological and pituitary-adrenal systems.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Healy, D L -- Hodgen, G D -- Schulte, H M -- Chrousos, G P -- Loriaux, D L -- Hall, N R -- Goldstein, A L -- CA 24974/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1983 Dec 23;222(4630):1353-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6318312" target="_blank"〉PubMed〈/a〉
    Keywords: Adrenocorticotropic Hormone/*blood ; Animals ; Dose-Response Relationship, Drug ; Endorphins/blood ; Female ; Hydrocortisone/blood ; Kinetics ; Macaca fascicularis ; Thymectomy ; Thymosin/analogs & derivatives/*pharmacology ; Thymus Gland/*physiology ; beta-Endorphin
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1983-03-04
    Description: Efforts in estimating carcinogenic risk in humans from long-term exposure to chemical carcinogens have centered on the problem of low-dose extrapolation. For chemicals with metabolites that interact with DNA, it may be more meaningful to relate tumor response to the concentration of the DNA adducts in the target organ rather than to the applied dose. Many data suggest that the relation between tumor response and concentration of DNA adducts in the target organ may be linear. This implies that the nonlinearities of the dose-response curve for tumor induction may be due to the kinetic processes involved in the formation of carcinogen metabolite--DNA adducts. Of particular importance is the possibility that the kinetic processes may show a nonlinear "hockey-stick" like behavior which results from saturation of detoxification or DNA repair processes. The mathematical models typically used for low-dose extrapolation are shown potentially to overestimate risk by several orders of magnitude when nonlinear kinetics are present.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hoel, D G -- Kaplan, N L -- Anderson, M W -- New York, N.Y. -- Science. 1983 Mar 4;219(4588):1032-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6823565" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Carcinogens/*administration & dosage ; Cell Transformation, Neoplastic/*drug effects ; DNA, Neoplasm/genetics ; Dose-Response Relationship, Drug ; Humans ; Kinetics ; Models, Biological ; Neoplasms/*chemically induced ; Risk
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Publication Date: 1983-11-25
    Description: Analysis of the polarized single-crystal absorption spectra of cytochrome cd1 of Pseudomonas aeruginosa shows that the heme c and heme d1 groups in each subunit are oriented perpendicularly to each other in both oxidized and reduced forms of the enzyme. These results, together with those of previous kinetic studies, indicate that a perpendicular heme-heme orientation may be an important factor in specifying kinetically slow steps in a sequential series of electron transfer reactions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Makinen, M W -- Schichman, S A -- Hill, S C -- Gray, H B -- 1-T32-HD-07009/HD/NICHD NIH HHS/ -- New York, N.Y. -- Science. 1983 Nov 25;222(4626):929-31.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6415814" target="_blank"〉PubMed〈/a〉
    Keywords: *Cytochromes ; *Electron Transport ; *Heme ; Kinetics ; *Nitrite Reductases ; Pseudomonas aeruginosa/enzymology ; Spectrum Analysis
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1983-12-09
    Description: Measurements of vapor pressures over their aqueous solutions indicate that organic compounds show profound differences in hydrophilic character. These differences are of such magnitude as to suggest an important role for changing solvation in determining free energy changes associated with metabolic transformations in water, and in governing structural equilibria of proteins and other large molecules in water. When two or more functional groups are present within the same solute molecule, their combined effects on its free energy of solvation are commonly additive. Striking departures from additivity, observed in certain cases, indicate the existence of special interactions between different parts of a solute molecule and the water that surrounds it. Similar considerations presumably apply to activated intermediates in the interconversion of biological materials.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wolfenden, R -- GM 18325/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1983 Dec 9;222(4628):1087-93.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6359416" target="_blank"〉PubMed〈/a〉
    Keywords: Chemistry, Organic ; Enzymes/physiology ; Kinetics ; Metabolism ; Nucleic Acid Conformation ; Nucleic Acids/physiology ; Organic Chemistry Phenomena ; Protein Conformation ; Solvents ; Water/*physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Publication Date: 1983-10-28
    Description: Fluorinated anesthetics were observed noninvasively in the brain of intact rabbits with fluorine-19 nuclear magnetic resonance spectroscopy. High-resolution fluorine-19 spectra of halothane, methoxyflurane, and isoflurane were obtained with a surface coil centered over the calvarium. Elimination of halothane from the brain was also monitored by this technique. Residual fluorine-19 signals from halothane (or a metabolite) could be detected as long as 98 hours after termination of anesthesia. These observations demonstrate the feasibility of using this technique to study the fate of fluorinated anesthetics in live mammals.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wyrwicz, A M -- Pszenny, M H -- Schofield, J C -- Tillman, P C -- Gordon, R E -- Martin, P A -- GM 29520/GM/NIGMS NIH HHS/ -- K04 GM 00503/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1983 Oct 28;222(4622):428-30.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6623084" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Brain/*metabolism ; Halothane/*metabolism ; Isoflurane/*metabolism ; Kinetics ; Magnetic Resonance Spectroscopy ; Methoxyflurane/*metabolism ; Methyl Ethers/*metabolism ; Rabbits
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1984-10-12
    Description: The impermeant dye antipyrylazo III was used to measure depletion of extracellular calcium and net influx of calcium through the sarcolemma during the cardiac action potential. It was found that calcium entry occurs continuously during the action potential and is under direct control of the membrane potential. The inotropic action of epinephrine is accompanied by increased influx of calcium, while strophanthidin enhances the twitch without altering calcium influx during the action potential.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cleemann, L -- Pizarro, G -- Morad, M -- HL16152/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1984 Oct 12;226(4671):174-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6091269" target="_blank"〉PubMed〈/a〉
    Keywords: Action Potentials ; Animals ; Calcium/*metabolism ; Epinephrine/pharmacology ; Extracellular Space/*metabolism ; Ion Channels ; Kinetics ; *Myocardial Contraction/drug effects ; Myocardium/*metabolism ; Naphthalenesulfonates ; Ranidae ; Sarcolemma/*metabolism ; Spectrophotometry ; Stimulation, Chemical ; Strophanthidin/pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1983-10-07
    Description: Acetylcholine receptors at innervated neuromuscular junctions are very stable, with half-lives reported to be 6 to 13 days. Their turnover is described as a first-order process, implying a single population of receptors. In this study, two subpopulations of acetylcholine receptors at normally innervated junctions have been identified. One has a rapid turnover rate with a half-life of 18.7 hours, similar to that of extrajunctional receptors, and the other has a slow turnover rate with a half-life of 12.4 days. The rapidly turned over subpopulation represents approximately 20 percent of the total junctional receptors. This finding may account for the discrepancies in previous reports of turnover rates and may explain the rapid reversibility in vivo of agents that "irreversibly" block acetylcholine receptors. This finding also implies that the synthesis rate of junctional acetylcholine receptors may be higher than previous estimates. The rapidly turned-over subpopulation may represent receptors that were newly inserted into the neuromuscular junction and that were not yet stabilized by an influence of the motor nerve.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stanley, E F -- Drachman, D B -- 5 P01 NS10920/NS/NINDS NIH HHS/ -- 5 R01 HD04817/HD/NICHD NIH HHS/ -- New York, N.Y. -- Science. 1983 Oct 7;222(4619):67-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6623057" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Bungarotoxins ; Diaphragm ; Kinetics ; Mice ; Neuromuscular Junction/*metabolism ; Receptors, Cholinergic/biosynthesis/classification/*metabolism ; Synaptic Membranes/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1984-11-02
    Description: New active sites can be introduced into naturally occurring enzymes by the chemical modification of specific amino acid residues with the use of appropriately designed coenzyme analogs. The resultant semisynthetic enzymes can have catalytic activities very different from those of the corresponding native enzymes. For example, papain has been converted into a highly effective oxidoreductase by covalent modification of the sulfhydryl group of the active site cysteine residue (Cys25) with flavins such as 8-bromoacetyl-10-methylisoalloxazine. Thus, it is now possible to enhance the catalytic versatility of existing enzymes through the process of "chemical mutation" of the active site.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kaiser, E T -- Lawrence, D S -- New York, N.Y. -- Science. 1984 Nov 2;226(4674):505-11.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6238407" target="_blank"〉PubMed〈/a〉
    Keywords: Anaerobiosis ; *Binding Sites ; Catalysis ; Chemical Phenomena ; *Chemistry ; Chymotrypsin ; Enzymes/*chemical synthesis ; Flavins ; Kinetics ; NAD/metabolism ; Niacinamide/analogs & derivatives ; Oxidation-Reduction ; Papain ; Stereoisomerism ; Toluene/analogs & derivatives/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Publication Date: 1984-08-03
    Description: Apolipoproteins A-1 and A-2 were purified from human plasma. At concentrations present in human bile these proteins prolonged the nucleation time of cholesterol monohydrate crystals when added to model systems of supersaturated bile. In contrast, apolipoprotein C-3 and other serum proteins did not have this effect. Also, when human gallbladder bile was fractionated by gel filtration chromatography, apolipoproteins A-1 and A-2 were among the proteins present in a fraction of bile enriched in potent inhibitors of cholesterol crystal nucleation. These findings suggest that apolipoproteins A-1 and A-2 in supersaturated human gallbladder bile could inhibit the rate of formation of solid cholesterol crystals and thus help to prevent spontaneous cholesterol gallstone formation in humans.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kibe, A -- Holzbach, R T -- LaRusso, N F -- Mao, S J -- AM-17562/AM/NIADDK NIH HHS/ -- AM-24031/AM/NIADDK NIH HHS/ -- HL-32317/HL/NHLBI NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1984 Aug 3;225(4661):514-6.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6429856" target="_blank"〉PubMed〈/a〉
    Keywords: Apolipoprotein A-I ; Apolipoprotein A-II ; Apolipoproteins/*blood ; Bile/*physiology ; Cholesterol/*metabolism ; Crystallization ; Gallbladder/physiology ; Humans ; Kinetics ; Lipoproteins, HDL/*blood ; Models, Biological
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Publication Date: 1984-02-10
    Description: Ultraviolet irradiation of rat dendritic cells completely abrogated their allostimulatory capacity in a mixed lymphocyte reaction. Rat islets of Langerhans similarly irradiated remained hormonally functional when transplanted into syngeneic diabetic rats. Allogeneic transplantation across a major histocompatibility barrier of islets initially treated in vitro with ultraviolet irradiation resulted in prolonged allograft survival without the use of any immunosuppressive agents.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lau, H -- Reemtsma, K -- Hardy, M A -- New York, N.Y. -- Science. 1984 Feb 10;223(4636):607-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6420888" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cell Survival/radiation effects ; Dose-Response Relationship, Radiation ; Islets of Langerhans/radiation effects ; *Islets of Langerhans Transplantation ; Kinetics ; Rats ; Rats, Inbred Lew ; Transplantation, Homologous ; Transplantation, Isogeneic ; *Ultraviolet Rays
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 1984-07-13
    Description: A significant postflight reduction in the circulating red cell mass has been observed in both the American and Soviet manned programs. The mechanism and etiology of this loss were studied in blood samples from the four payload crewmen of Spacelab 1 taken before, during, and after flight. These samples and samples from control groups on the ground were analyzed for selected hematological and biochemical parameters, which were chosen on the basis of data previously collected, the restraints imposed by the use of human subjects, and the guidelines established for the first Spacelab mission. Twenty-two hours after weightless exposure, there was an increase in hemoglobin and hematocrit. On day 7 in flight, the hemoglobin and hematocrit remained high and there was a slight decrease in reticulocyte number. On landing, red cell mass, plasma volume, hematocrit, and reticulocyte number were decreased. Throughout the 2-week postflight sampling period, hemoglobin, hematocrit, and reticulocyte number remained below the preflight value. Since this crew was not exposed to 100 percent oxygen these results are viewed as evidence that other spaceflight factors cause the measured red cell mass reduction.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Leach, C S -- Johnson, P C -- New York, N.Y. -- Science. 1984 Jul 13;225(4658):216-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6729477" target="_blank"〉PubMed〈/a〉
    Keywords: Erythrocyte Count ; Erythrocyte Volume ; Erythrocytes/*physiology ; Erythropoiesis ; Erythropoietin/blood ; Hematocrit ; Hemoglobins/analysis ; Humans ; Kinetics ; Reticulocytes ; *Space Flight
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Publication Date: 1984-02-10
    Description: 3-Aminobenzamide and benzamide, purported to be specific inhibitors of the synthesis of poly(adenosine diphosphate-ribose), were used to elucidate possible functions of this biopolymer. These compounds, at frequently used experimental concentrations, not only inhibited the action of poly(adenosine diphosphate-ribose) synthetase but also affected cell viability, glucose metabolism, and DNA synthesis. Thus, the usefulness of 3-aminobenzamide and benzamide may be severely restricted by the difficulty of finding a dose small enough to inhibit the synthetase without producing additional metabolic effects.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Milam, K M -- Cleaver, J E -- New York, N.Y. -- Science. 1984 Feb 10;223(4636):589-91.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6420886" target="_blank"〉PubMed〈/a〉
    Keywords: Benzamides/*toxicity ; Cell Line ; DNA Replication/drug effects ; Humans ; Kinetics ; Lymphocytes ; Nucleoside Diphosphate Sugars/*biosynthesis ; Poly Adenosine Diphosphate Ribose/*biosynthesis ; Poly(ADP-ribose) Polymerases/metabolism ; Structure-Activity Relationship
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Publication Date: 1984-05-11
    Description: Arabinosylcytosine, a compound that inhibits DNA synthesis in rapidly dividing cells, stimulates fetal hemoglobin in adult baboons and produces significant perturbations in the pools of erythroid progenitors. It appears that changes in the kinetics of erythroid cell differentiation rather than direct action on the gamma genes underlie stimulation of fetal hemoglobin in the adult animals in vivo. These results also suggest that chemotherapeutic agents selected for their low carcinogenic or mutagenic potential could be used for therapeutic induction of fetal hemoglobin in patients with sickle cell anemia.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Papayannopoulou, T -- Torrealba de Ron, A -- Veith, R -- Knitter, G -- Stamatoyannopoulos, G -- GM 15253/GM/NIGMS NIH HHS/ -- HL-07093/HL/NHLBI NIH HHS/ -- HL-20899/HL/NHLBI NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1984 May 11;224(4649):617-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6200940" target="_blank"〉PubMed〈/a〉
    Keywords: Anemia, Sickle Cell/drug therapy ; Animals ; Cell Differentiation/*drug effects ; Cytarabine/*pharmacology/therapeutic use ; Erythropoiesis/*drug effects ; Fetal Hemoglobin/*biosynthesis ; Kinetics ; Papio ; Reticulocytes/drug effects
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Publication Date: 1984-11-16
    Description: The benzodiazepine-gamma-aminobutyric acid receptor complex was used to study functional receptor synthesis and degradation in primary cultures of neurons. Fifty percent of the receptors turned over with an unusually rapid half-life (4 hours); this was followed by a second, slower phase (32 hours). These results provide the basis for elucidating the mechanism by which neurons derived from the central nervous system control neurotransmitter receptor number, an important problem in cellular neurobiology. The findings may be of significance in the study of neurological and psychiatric disorders.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Borden, L A -- Czajkowski, C -- Chan, C Y -- Farb, D H -- New York, N.Y. -- Science. 1984 Nov 16;226(4676):857-60.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6093257" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cells, Cultured ; Chick Embryo ; Flunitrazepam/metabolism ; Half-Life ; Kinetics ; Neurons/*metabolism ; Receptors, GABA-A/biosynthesis/*metabolism ; Spinal Cord/cytology ; gamma-Aminobutyric Acid/physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...