Abstract:
:Retroviral gene expression is inhibited in embryonal carcinoma (EC) cells. We have constructed a recombinant retroviral vector that is capable of expressing the neomycin-resistance (neo) gene in EC cells. The critical modification that permits expression of the neo gene is the insertion of a composite simian virus 40 early gene-herpes simplex virus type 1 thymidine kinase gene (SVtk) promoter 3' to the viral first intron and 5' to the neo gene. When the SVtk promoter is deleted, the recombinant retrovirus is either unable or extremely inefficient at expressing the neo gene in EC cells.
journal_name
Proc Natl Acad Sci U S Aauthors
Rubenstein JL,Nicolas JF,Jacob Fdoi
10.1073/pnas.81.22.7137subject
Has Abstractpub_date
1984-11-01 00:00:00pages
7137-40issue
22eissn
0027-8424issn
1091-6490journal_volume
81pub_type
杂志文章abstract::Many substances in the plant kingdom and in man's diet occur as glycosides. Recent studies have indicated that many glycosides that are not mutagenic in tests such as the Salmonella test become mutagenic upon hydrolysis of the glycosidic linkages. The Salmonella test utilizes a liver homogenate to approximate mammalia...
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.77.8.4961
更新日期:1980-08-01 00:00:00
abstract::In a study of autonomic reflexes it was found that some produce a generalized, bilaterally uniform response whereas others have an asymmetric or laterality of action. Recordings from vertebral nerve fibers (mainly vasoconstrictors to forelimb muscles), right and left cardiac sympathetics, and renal nerves show that ba...
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.75.10.5239
更新日期:1978-10-01 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::Blood viscosity decreases with shear stress, a property essential for an efficient perfusion of the vascular tree. Shear thinning is intimately related to the dynamics and mutual interactions of RBCs, the major component of blood. Because of the lack of knowledge about the behavior of RBCs under physiological conditio...
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.1608074113
更新日期:2016-11-22 00:00:00
abstract::Total nuclear proteins extracted from cell lines representing various stages of differentiation of mouse B lymphocytes were studied by computer analysis of two-dimensional gels. Of the 1438 spots present on the gels, 55 varied significantly in intensity during differentiation. The variations occurred most often in ste...
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.88.5.1830
更新日期:1991-03-01 00:00:00
abstract::The most frequent form of inherited amyloidoses is associated with mutations in the transthyretin (TTR) gene coding for 127-amino acid residues of four identical, noncovalently linked subunits that form a pair of dimers in the plasma protein complex. Amyloid fibrils containing the variant and to a lesser extent the wi...
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.93.13.6302
更新日期:1996-06-25 00:00:00
abstract::Computers are organized into hardware and software. Using a theoretical approach to identify patterns in gene expression in a variety of species, organs, and cell types, we found that biological systems similarly are comprised of a relatively unchanging hardware-like gene pattern. Orthogonal patterns of software-like ...
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.1200790109
更新日期:2012-03-20 00:00:00
abstract::The dramatic increase in healthcare cost has become a significant burden to the world. Many patients are denied the accessibility of medication because of the high price of drugs. Total biosynthesis of chiral drug intermediates is an environmentally friendly approach that helps provide more affordable pharmaceuticals....
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.0912903107
更新日期:2010-04-06 00:00:00
abstract::Tripartite motif 39 (Trim39) is a RING domain-containing E3 ubiquitin ligase able to inhibit the anaphase-promoting complex (APC/C) directly. Through analysis of Trim39 function in p53-positive and p53-negative cells, we have found, surprisingly, that p53-positive cells lacking Trim39 could not traverse the G1/S trans...
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.1212047110
更新日期:2012-12-18 00:00:00
abstract::Mammalian ferritin from horse spleen undergoes an electrochemical or chemical reduction reaction in which each iron atom present is reduced by one electron (2300 electrons per ferritin molecule containing 2300 Fe3+ ions). Midpoint potentials of -190 mV, -310 mV, and -416 mV were determined at pH 7.0, 8.0, and 9.0. Thi...
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.82.11.3640
更新日期:1985-06-01 00:00:00
abstract::Binding enhancement by tertiary interactions is a strategy that takes advantage of the higher order folding of functionally important RNAs to bind short nucleic acid-based compounds tightly and more specifically than possible by simple base pairing. For example, tertiary interactions enhance binding of specific hexame...
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.96.6.2734
更新日期:1999-03-16 00:00:00
abstract::Pentamidine, diminazene aceturate (Berenil), isometamidium chloride (Samorin), and ethidium bromide, which are important antitrypanosomal drugs, promote linearization of Trypanosoma equiperdum minicircle DNA (the principal component of kinetoplast DNA, the mitochondrial DNA in these parasites). This effect occurs at 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.87.3.950
更新日期:1990-02-01 00:00:00
abstract::Purified oat phytochrome was labeled with (125)I without altering the photoreversibility or absorbance properties of the pigment. The radiolabeled phytochrome was used in experiments in vitro to quantitate the binding of the pigment to both crude and purified membrane preparations from oat tissue. After the membranes ...
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.74.10.4439
更新日期:1977-10-01 00:00:00
abstract::Lon is an ATPase associated with cellular activities (AAA+) protease that controls cell division in response to stress and also degrades misfolded and damaged proteins. Subunits of Lon are known to assemble into ring-shaped homohexamers that enclose an internal degradation chamber. Here, we demonstrate that hexamers 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.1307066110
更新日期:2013-05-28 00:00:00
abstract::Seemingly similar individuals often experience drastically different success trajectories, with some repeatedly failing and others consistently succeeding. One explanation is preexisting variability along unobserved fitness dimensions that is revealed gradually through differential achievement. Alternatively, positive...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,随机对照试验
doi:10.1073/pnas.1316836111
更新日期:2014-05-13 00:00:00
abstract::In a medium without Na+, gamma-aminobutyric acid (GABA) binds at 0 degrees to freshly prepared crude synaptic membranes from rat cerebral cortex with an apparent dissociation constant of 218 nM. An endogenous inhibitor of the Na+-independent GABA binding was removed from these membranes by freezing and thawing and by ...
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.75.8.4024
更新日期:1978-08-01 00:00:00
abstract::The influx of Ca ions into the presynaptic nerve terminal through ion channels is a key link between the action potential and the release of chemical transmitters. It is not clear, however, which types of Ca channel are involved in neurosecretion at vertebrate synapses. In particular, there is disagreement as to wheth...
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.87.24.9683
更新日期:1990-12-01 00:00:00
abstract::Proopiomelanocortin (POMC), a major pituitary product, is also present in the adult mouse testis. We have shown previously that POMC mRNAs are most abundant in a subpopulation of Leydig cells associated with tubules in specific stages of the cycle of the seminiferous epithelium. In the present study, we examined the e...
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.84.6.1600
更新日期:1987-03-01 00:00:00
abstract::Pseudohypoparathyroidism type Ia (PHP-Ia) results from the loss of one allele of G(salpha), causing resistance to parathyroid hormone and other hormones that transduce signals via G(s). Most G(salpha)mutations cause the complete loss of protein expression, but some cause loss of function only, and these have provided ...
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.0708561104
更新日期:2007-10-30 00:00:00
abstract::The gene encoding human plakoglobin was mapped to chromosome 17q12-q22. An intragenic restriction fragment length polymorphism was used to localize the plakoglobin gene distal to locus KRT10 and proximal to the marker D17S858. The plakoglobin gene colocalizes with the polymorphic 17q21 marker UM8 on the same cosmid in...
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.92.14.6384
更新日期:1995-07-03 00:00:00
abstract::We have applied a molecular biology approach to the identification of human monoclonal antibodies. Human peripheral blood lymphocyte mRNA was converted to cDNA and a select subset was amplified by the polymerase chain reaction. These products, containing coding sequences for numerous immunoglobulin heavy- and kappa li...
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.87.20.8095
更新日期:1990-10-01 00:00:00
abstract::pRK212.2, a derivative of the broad host range plasmid RK2, contains two EcoRI cleavage fragments, A and B, neither of which can replicate by itself in Escherichia coli. Fragment A (41.7 kilobases), but not fragment B (14.4 kilobases), can be cloned by insertion into the unrelated plasmids mini-F and ColE1. Fragment B...
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.76.4.1648
更新日期:1979-04-01 00:00:00
abstract::Cyclophilins are a family of ubiquitous proteins that are the intracellular target of the immunosuppressant drug cyclosporin A. Although cyclophilins catalyze peptidylprolyl cis-trans isomerization in vitro, it has remained open whether they also perform this function in vivo. Here we show that Cpr3p, a cyclophilin in...
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.92.14.6319
更新日期:1995-07-03 00:00:00
abstract::Mycobacterium marinum, a natural pathogen of fish and frogs and an occasional pathogen of humans, is capable of inducing actin tail formation within the cytoplasm of macrophages, leading to actin-based motility and intercellular spread. Actin tail formation by M. marinum is markedly reduced in macrophages deficient in...
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.0504663102
更新日期:2005-10-11 00:00:00
abstract::Incubation of O6-[3H]ethylguanine-containing DNA with a rat liver chromatin fraction resulted in a decrease in the O6-ethylguanine content of the DNA. Analysis of the products of this reaction showed that the ethyl group had been transferred from the O6-ethylguanine to a protein acceptor. When the incubation mixture w...
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.78.11.6766
更新日期:1981-11-01 00:00:00
abstract::The frequency of recombination between the G gamma-globin (HBG2) and parathyroid hormone (PTH) loci on the short arm of human chromosome 11 was estimated by typing greater than 700 single-sperm samples from two males. The sperm-typing technique employed involves the polymerase chain reaction and allele-specific oligon...
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.86.23.9389
更新日期:1989-12-01 00:00:00
abstract::Platelet-derived growth factor (PDGF) isoforms lead to mitogenic, survival, and chemotactic responses in a variety of mesenchymal cell types during development and in the adult. We have studied the importance of phosphatidylinositol-3' kinase (PI3K) signaling in these responses by mutating the PI3K-binding sites in th...
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.96.20.11410
更新日期:1999-09-28 00:00:00
abstract::Knowledge of the range and chronology of historic trade and long-distance transport of natural resources is essential for determining the impacts of past human activities on marine environments. However, the specific biological sources of imported fauna are often difficult to identify, in particular if species have a ...
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.1710186114
更新日期:2017-08-22 00:00:00
abstract::The p21(WAF1) (p21) cyclin-dependent kinase inhibitor plays a major role in regulating cell cycle arrest. It was recently reported that the p53-independent elevation of p21 protein levels is essential in mediating the G(1) arrest resulting from signal transduction events initiated by the crosslinking of membrane IgM 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.96.15.8711
更新日期:1999-07-20 00:00:00
abstract::Alzheimer's disease (AD) and other neurodegenerative disorders are associated with the cytoplasmic aggregation of microtubule-associated protein tau. Recent evidence supports transcellular transfer of tau misfolding (seeding) as the mechanism of spread within an affected brain, a process reminiscent of viral infection...
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.1607215114
更新日期:2017-01-17 00:00:00