Abstract:
:The role of ornithine decarboxylase (OrnDCase, EC 4.1.1.17) and of the polyamines [putrescine (Put), spermidine (Spd), and spermine (Spm)] in mouse skin tumor promotion was investigated by the use of alpha-difluoromethylornithine (CHF2-Orn), an enzyme-activated irreversible inhibitor of OrnDCase. 12-O-Tetradecanoylphorbol 13-acetate (TPA), mezerein, and ethyl phenylpropiolate (EPP) were employed as complete, stage II specific, and nonpromoting agents, respectively. TPA and mezerein, but not EPP, provided for a dose-dependent increase in tissue Put accumulation. The Put level in papillomas developed by TPA (2 micrograms) treatment was approximately equal to 15-fold higher than that of the surrounding skin tissue; Spd accumulation was 2- to 3-fold greater in the papillomas. Put administered (intraperitoneally) with TPA greatly enhanced papilloma yield. CHF2-Orn, given orally or intraperitoneally, abolished the TPA-induced OrnDCase activity and Put accumulation in mouse epidermis. The reduction of polyamine accumulation by CHF2-Orn was directly proportional to reduction of tumor size. CHF2-Orn administered in a two-stage (TPA-mezerein) promotion protocol [Slaga, T. J., Fischer, S. M., Nelson, K. G. & Gleason, G. L. (1980) Proc. Natl. Acad. Sci. USA 77, 3659-3663; Slaga, T. J., Klein-Szanto, A. J. P., Fischer, S. M., Weeks, C. E., Nelson, K. & Major, S. (1980) Proc. Natl. Acad. Sci. USA 77, 2251-2254] reduced tumor size, inhibited by 65-70% the number of papillomas per mouse, and decreased by 40% the percentage of mice with tumors when given with the stage II agent mezerein. CHF2-Orn provided considerably less effect on tumorigenesis when administered with the TPA portion of the protocol, and CHF2-Orn did not inhibit the induction of dark basal keratinocytes by TPA. Based on our results with CHF2-Orn, we suggest that regulation of polyamine biosynthesis, particularly Put, is a critical factor in stage II promotion.
journal_name
Proc Natl Acad Sci U S Aauthors
Weeks CE,Herrmann AL,Nelson FR,Slaga TJdoi
10.1073/pnas.79.19.6028subject
Has Abstractpub_date
1982-10-01 00:00:00pages
6028-32issue
19eissn
0027-8424issn
1091-6490journal_volume
79pub_type
杂志文章abstract::The 24-hr intracarotid infusion of plasma-treated glycyl-L-glutamine (3 microM) produced significant enhancement of the monomeric G1 and tetrameric G4 forms of acetylcholinesterase of the cat superior cervical ganglion 48 hr after denervation, in comparison with denervated, noninfused controls. No significant effect o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.16.6215
更新日期:1988-08-01 00:00:00
abstract::Cellular membranes are a heterogeneous mix of lipids, proteins and small molecules. Special groupings enriched in saturated lipids and cholesterol form liquid-ordered domains, known as "lipid rafts," thought to serve as platforms for signaling, trafficking and material transport throughout the secretory pathway. Quest...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0903825106
更新日期:2009-08-11 00:00:00
abstract::Sex differences influence brain morphology and physiology during both development and aging. Here we apply a machine learning algorithm to a multiparametric brain PET imaging dataset acquired in a cohort of 20- to 82-year-old, cognitively normal adults (n = 205) to define their metabolic brain age. We find that throug...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1815917116
更新日期:2019-02-19 00:00:00
abstract::Site-specific recombination is responsible for a broad range of biological phenomena, including DNA inversion, resolution of transposition intermediates, and the integration and excision of bacteriophage genomes. Integration of mycobacteriophage L5 is catalyzed by a phage-encoded integrase with recombination occurring...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.140014297
更新日期:2000-07-05 00:00:00
abstract::In contrast with speciation in terrestrial organisms, marine plankton frequently display gradual morphological change without lineage division (e.g., phyletic gradualism or gradual evolution), which has raised the possibility that a different mode of evolution dominates within pelagic environments. Here, we reexamine ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.0902887106
更新日期:2009-12-15 00:00:00
abstract::We describe the partial purification of an endonuclease from calf thymus that nicks phage PM2 DNA irradiated with UV doses producing only a few pyrimidine dimers per molecule. It has much less activity on DNA that has been subjected to enzymatic photoreactivation after UV irradiation. The calf thymus endonuclease is d...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.8.3746
更新日期:1979-08-01 00:00:00
abstract::Ca(2+)-sensitive kinases are thought to play a role in long-term potentiation (LTP). To test the involvement of Ca2+/calmodulin-dependent kinase II (CaM-K II), truncated, constitutively active form of this kinase was directly injected into CA1 hippocampal pyramidal cells. Inclusion of CaM-K II in the recording pipette...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.24.11175
更新日期:1995-11-21 00:00:00
abstract::To facilitate genetic analysis of the human pathogenic parvovirus B19, we constructed a hybrid B19 viral genome in which the defective B19 inverted terminal repeats were replaced with the full-length inverted terminal repeats from a nonpathogenic human parvovirus, the adeno-associated virus 2 (AAV). The hybrid AAV-B19...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.20.8078
更新日期:1989-10-01 00:00:00
abstract::We describe a technique for transferring electrophoretically separated bands of RNA from an agarose gel to paper strips. The RNA is coupled covalently to diazobenzyloxymethyl groups on the paper. After transfer and appropriate treatment of the paper to destroy remaining diazo groups, specific RNA bands can be detected...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.74.12.5350
更新日期:1977-12-01 00:00:00
abstract::In earlier studies it was shown that the mammalian translation system is highly organized in vivo and that the intermediates in the process, aminoacyl-tRNAs, are channeled--i.e., they are directly transferred from the aminoacyl-tRNA synthetases to the elongation factor to the ribosomes without dissociating into the ce...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.16.7158
更新日期:1995-08-01 00:00:00
abstract::The photoproduct of carbon monoxide myoglobin generated at 4 K and lower has a resonance Raman spectrum characteristic of a high-spin heme but in which the high-frequency core size-sensitive lines are at lower frequency than those in the deoxy preparation. Such differences are not detected in the photoproduct generate...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.5.1310
更新日期:1986-03-01 00:00:00
abstract::We investigated the operation of a posttranslational protein translocation pathway to determine whether ions are excluded from the translocase during protein transport. The membrane capacitance during protein translocation across chloroplast thylakoid membranes was monitored via electric-field-indicating carotenoid el...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.4.1590
更新日期:1998-02-17 00:00:00
abstract::Newly formed hepatic granulomas around Schistosoma mansoni eggs become progressively smaller during the chronic (greater than or equal to 15 weeks after infection) phase of the disease. This reduction in granuloma size, termed "modulation," is known to be caused in part by a T lymphocyte that can adoptively transfer m...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.2.1152
更新日期:1981-02-01 00:00:00
abstract::Rat liver glutamine synthetase (s(20,w) 15.0 S; MW about 352,000) resembles ovine brain glutamine synthetase in that it (a) has 8 subunits, (b) acts on both L- and D-glutamate and certain glutamate analogs (e.g., beta-glutamate, cis-cycloglutamate, and alpha-methyl-L-glutamate), and (c) is irreversibly inhibited by L-...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.68.4.781
更新日期:1971-04-01 00:00:00
abstract::β subunits of high voltage-gated Ca2+ (CaV) channels promote cell-surface expression of pore-forming α1 subunits and regulate channel gating through binding to the α-interaction domain (AID) in the first intracellular loop. We addressed the stability of CaV α1B-β interactions by rapamycin-translocatable CaV β subunits...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1809762115
更新日期:2018-10-16 00:00:00
abstract::Human rhinovirus (HRV) and other members of the enterovirus genus bind small-molecule antiviral compounds in a cavity buried within the viral capsid protein VP1. These compounds block the release of the viral protein VP4 and RNA from inside the capsid during the uncoating process. In addition, the antiviral compounds ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1119174109
更新日期:2012-04-03 00:00:00
abstract::Ligand specificity of a murine gammadelta T-cell receptor-expressing hybridoma (KN6) derived from adult thymocytes has been analyzed in detail. The molecule recognized by the KN6 gammadelta T-cell receptor is expressed on syngeneic cells of various sources (peritoneal macrophages, thymocytes, spleen cells, and Abelson...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.15.5928
更新日期:1989-08-01 00:00:00
abstract::Animal foraging and competition are defined by the partitioning of three primary niche axes: space, time, and resources. Human disturbance is rapidly altering the spatial and temporal niches of animals, but the impact of humans on resource consumption and partitioning-arguably the most important niche axis-is poorly u...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2012774117
更新日期:2020-10-27 00:00:00
abstract::The usual way to compute Hartree-Fock type functions for molecules is by an expansion of the one-electron functions (molecular orbitals) in a linear combination of analytical functions (LCAO-MO-SCF, linear combination of atomic orbitals-Molecular Orbital-Self Consistent field). The expansion coefficients are obtained ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.69.10.2942
更新日期:1972-10-01 00:00:00
abstract::The tubercle bacillus parasitizes macrophages by inhibiting phagosome maturation into the phagolysosome. This phenomenon underlies the tuberculosis pandemic involving 2 billion people. We report here how Mycobacterium tuberculosis causes phagosome maturation arrest. A glycosylated M. tuberculosis phosphatidylinositol ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0737613100
更新日期:2003-04-29 00:00:00
abstract::Several inhibitors of gamma-glutamyl transpeptidase in vitro [L-serine plus borate, 6-diazo-5-oxo-L-norleucine, and L- and D-gamma-glutamyl-(o-carboxy)phenylhydrazide] are active in vivo, as indicated by their effect in decreasing the conversion of administered D-gamma-glutamyl-L-alpha-amino[(14)C]butyrate to respirat...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.1.268
更新日期:1979-01-01 00:00:00
abstract::The complement system is highly efficient in targeting pathogens, but lack of its apposite regulation results in host-cell damage, which is linked to diseases. Thus, complement activation is tightly regulated by a series of proteins, which primarily belong to the regulators of complement activation (RCA) family. Struc...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1818573116
更新日期:2019-05-14 00:00:00
abstract::Insertion of trocars, needles, and catheters into unintended tissues or tissue compartments results in hundreds of thousands of complications annually. Current methods for blood vessel cannulation or epidural, chest tube, and initial trocar placement often involve the blind pass of a needle through several layers of t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0808274106
更新日期:2009-04-07 00:00:00
abstract::Monoclonal antibodies (mAbs) against purified human placental insulin-like growth factor I (IGF-I) receptors were prepared and characterized. Three IgG mAbs were specific for the human IGF-I receptor and displayed negligible crossreactivity with the human insulin receptor. They stimulated 125I-labeled IGF-I (125I-IGF-...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.12.5356
更新日期:1992-06-15 00:00:00
abstract::The het-s locus of Podospora anserina is a heterokaryon incompatibility locus. The coexpression of the antagonistic het-s and het-S alleles triggers a lethal reaction that prevents the formation of viable heterokaryons. Strains that contain the het-s allele can display two different phenotypes, [Het-s] or [Het-s*], ac...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.18.9773
更新日期:1997-09-02 00:00:00
abstract::We have developed a culture system, simulating in vivo conditions of human immunodeficiency virus type 1 (HIV-1) infection, to evaluate the long-term efficacy of antisense oligonucleotide treatment. Five oligonucleotide phosphorothioates (28-mers), complementary to different regions of HIV-1 RNA, blocked replication o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.23.11209
更新日期:1992-12-01 00:00:00
abstract::The nature of color categories in the world's languages is contested. One major view holds that color categories are organized around universal focal colors, whereas an opposing view holds instead that categories are defined at their boundaries by linguistic convention. Both of these standardly opposed views are chall...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0610341104
更新日期:2007-01-23 00:00:00
abstract::Seasonal cycles govern life on earth, from setting the time for the mating season to influencing migrations and governing physiological conditions like hibernation. The effect of such changing conditions on behavior is well-appreciated, but their impact on the brain remains virtually unknown. We investigate long-term ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1922888117
更新日期:2020-12-15 00:00:00
abstract::We have analyzed ligand-receptor complexes resulting from (i) the incubation of canine hepatic plasma membranes with [125I]iodoglucagon and (ii) subsequent gentle solubilization of receptor-bound ligand with digitonin. The complexes (molecular weight approximately equal to 500,000) retain the radiolabeled ligand durin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.20.6835
更新日期:1985-10-01 00:00:00
abstract::Endothelial cell growth factor (ECGF) binds specifically in vitro to membrane receptors present on the surface of several cell types, including murine and human endothelial cells and fibroblasts. Monoclonal antibodies prepared against ECGF that inhibit the mitogenic activity of the growth factor prevent receptor occup...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.18.6138
更新日期:1985-09-01 00:00:00