Quantitative assessment of the role of O6-methylguanine in the initiation of carcinogenesis by methylating agents.

abstract：:Patients undergoing treatment at a community-based renal dialysis clinic were monitored monthly for hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti-HBs). Of 160 patients who began treatment HBsAg(-)/anti-HBs(-), 77 subsequently became HBsAg(+). Once HBsAg(+), males were more likely to remain HBsAg(+) i...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： London WT,Drew JS

更新日期：1977-06-01 00:00:00

abstract：:Temporal dynamics of urban warming have been extensively studied at the diurnal scale, but the impact of background climate on the observed seasonality of surface urban heat islands (SUHIs) remains largely unexplored. On seasonal time scales, the intensity of urban-rural surface temperature differences ([Formula: see ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Manoli G,Fatichi S,Bou-Zeid E,Katul GG

更新日期：2020-03-31 00:00:00

abstract：:The protein CopC from Pseudomonas syringae has been found capable of binding copper(I) and copper(II) at two different sites, occupied either one at a time or simultaneously. The protein, consisting of 102 amino acids, is known to bind copper(II) in a position that is now found consistent with a coordination arrangeme...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Arnesano F,Banci L,Bertini I,Mangani S,Thompsett AR

更新日期：2003-04-01 00:00:00

abstract：:Ribonucleotide reductase provides deoxynucleotides for nuclear and mitochondrial (mt) DNA replication and repair. The mammalian enzyme consists of a catalytic (R1) and a radical-generating (R2 or p53R2) subunit. During S-phase, a R1/R2 complex is the major provider of deoxynucleotides. p53R2 is induced by p53 after DN...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Pontarin G,Fijolek A,Pizzo P,Ferraro P,Rampazzo C,Pozzan T,Thelander L,Reichard PA,Bianchi V

更新日期：2008-11-18 00:00:00

abstract：:The protein dystrophin, normally found on the cytoplasmic surface of skeletal muscle cell membranes, is absent in patients with Duchenne muscular dystrophy as well as mdx (X-linked muscular dystrophy) mice. Although its primary structure has been determined, the precise functional role of dystrophin remains the subjec...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Petrof BJ,Shrager JB,Stedman HH,Kelly AM,Sweeney HL

更新日期：1993-04-15 00:00:00

abstract：:Nitrofurans, a class of antibacterial drugs in extensive use, interferes with gene expression in a highly specific manner. While in the low dose range (0.5-25 mug/ml), 5-nitro-2-furfurylidene-1-aminohydantoin has no effect on transcription, it inhibits specifically the expression of one class of genes in translation. ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Herrlich P,Schweiger M

更新日期：1976-10-01 00:00:00

abstract：:The interaction between cells and nanostructured materials is attracting increasing interest, because of the possibility to open up novel concepts for the design of smart nanobiomaterials with active biological functionalities. In this frame we investigated the response of human neuroblastoma cell line (SH-SY5Y) to go...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Brunetti V,Maiorano G,Rizzello L,Sorce B,Sabella S,Cingolani R,Pompa PP

更新日期：2010-04-06 00:00:00

abstract：:One of the major surprises of the molecular analysis of major histocompatibility complex (MHC) genes is the large number of class I (K/D)-related sequences in the genome. Both restriction fragment length polymorphisms and cosmid cloning experiments showed them all to be closely linked to the MHC. Until now little info...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schepart BS,Woodward JG,Palmer MJ,Macchi MJ,Basta P,McLaughlin-Taylor E,Frelinger JA

更新日期：1985-08-01 00:00:00

abstract：:Plants in dense vegetation compete for resources, including light, and optimize their growth based on neighbor detection cues. The best studied of such behaviors is the shade-avoidance syndrome that positions leaves in optimally lit zones of a vegetation. Although proximate vegetation is known to be sensed through a r...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： de Wit M,Kegge W,Evers JB,Vergeer-van Eijk MH,Gankema P,Voesenek LA,Pierik R

更新日期：2012-09-04 00:00:00

abstract：:Efforts to delineate the advent of many enzymes essential to protein translation are often limited by the fact that the modern genetic code evolved before divergence of the tree of life. Glutaminyl-tRNA synthetase (GlnRS) is one noteworthy exception to the universality of the translation apparatus. In eukaryotes and s...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Skouloubris S,Ribas de Pouplana L,De Reuse H,Hendrickson TL

更新日期：2003-09-30 00:00:00

abstract：:Understanding the molecular mechanisms of osmolyte protection in protein stability has proved to be challenging. In particular, little is known about the role of osmolytes in the structure of the unfolding transition state of a protein, the main determinant of its dynamics. We have developed an experimental protocol t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Dougan L,Genchev GZ,Lu H,Fernandez JM

更新日期：2011-06-14 00:00:00

abstract：:Two methods for increasing the length of DNA sequence data that can be read off a polyacrylamide gel are described. We have developed a rapid way to pour a buffer concentration gradient gel that, by altering the vertical band separation on an autoradiograph, allows more sequence to be obtained from a gel. We also show...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Biggin MD,Gibson TJ,Hong GF

更新日期：1983-07-01 00:00:00

abstract：:Despite significant infiltration into tumors and atherosclerotic plaques, the role of T lymphocytes in these pathological conditions is still unclear. We have demonstrated that tumor-infiltrating lymphocytes (TILs) and plaque-infiltrating lymphocytes (PILs) produce heparin-binding epidermal growth factor-like growth f...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Peoples GE,Blotnick S,Takahashi K,Freeman MR,Klagsbrun M,Eberlein TJ

更新日期：1995-07-03 00:00:00

abstract：:According to the lipid raft hypothesis, biological lipid membranes are laterally heterogeneous and filled with nanoscale ordered "raft" domains, which are believed to play an important role for the organization of proteins in membranes. However, the mechanisms stabilizing such small rafts are not clear, and even their...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Meinhardt S,Vink RL,Schmid F

更新日期：2013-03-19 00:00:00

abstract：:We have used the spreading behavior of small drops of several fluorocarbon fluids and silicone oil on air-liquid interfaces to measure the surface tension of lungs in situ. The test fluids were calibrated in a surface balance at 37 degrees on monolayers of dipalmitoylphosphatidylcholine. At particular surface tensions...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schürch S,Goerke J,Clements JA

更新日期：1976-12-01 00:00:00

abstract：:NaeI is a remarkable type II restriction endonuclease. It must bind two recognition sequences to cleave DNA, forms a covalent protein-DNA intermediate, and is only 1 aa change away from topoisomerase and recombinase activity. The latter activities apparently derive from reactivation of a cryptic DNA ligase active site...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Colandene JD,Topal MD

更新日期：1998-03-31 00:00:00

abstract：:Molecular beacons are FRET-based target-activatable probes. They offer control of fluorescence emission in response to specific cancer targets, thus are useful tools for in vivo cancer imaging. Photodynamic therapy (PDT) is a cell-killing process by light activation of a photosensitizer (PS) in the presence of oxygen....

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Zheng G,Chen J,Stefflova K,Jarvi M,Li H,Wilson BC

更新日期：2007-05-22 00:00:00

abstract：:Ferredoxin:NADP oxidoreductases (FNRs) constitute a family of flavoenzymes that catalyze the exchange of reducing equivalents between one-electron carriers and the two-electron-carrying NADP(H). The main role of FNRs in cyanobacteria and leaf plastids is to provide the NADPH for photoautotrophic metabolism. In root pl...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Thomas JC,Ughy B,Lagoutte B,Ajlani G

更新日期：2006-11-28 00:00:00

abstract：:ApcMin (Min, multiple intestinal neoplasia) is a point mutation in the murine homolog of the APC gene. Min/+ mice develop multiple intestinal adenomas, as do humans carrying germ-line mutations in APC. Female mice carrying Min are also prone to develop mammary tumors. Min/+ mammary glands are more sensitive to chemica...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Moser AR,Mattes EM,Dove WF,Lindstrom MJ,Haag JD,Gould MN

更新日期：1993-10-01 00:00:00

abstract：:Small RNAs (sRNAs) are hypothesized to contribute to hybrid vigor because they maintain genome integrity, contribute to genetic diversity, and control gene expression. We used Illumina sequencing to assess how sRNA populations vary between two maize inbred lines (B73 and Mo17) and their hybrid. We sampled sRNAs from t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Barber WT,Zhang W,Win H,Varala KK,Dorweiler JE,Hudson ME,Moose SP

更新日期：2012-06-26 00:00:00

abstract：:The plasma concentration of the major vitamin D metabolites; 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and 24,25-dihydroxyvitamin D were measured during pregnancy and lactation in the adult female rat. The concentrations of these metabolites were also measured in rat pups during lactation and after weaning. The pl...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Halloran BP,Barthell EN,DeLuca HF

更新日期：1979-11-01 00:00:00

abstract：:The transcription factor retinoic acid receptor beta(2) (RARbeta(2)) is a potent inhibitor of breast cancer cells in vitro, and studies suggest that RARbeta expression is lost in primary breast cancer. Although RARbeta(2) is selectively down-regulated at the mRNA level in breast tumor cells, we show that expression of...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sommer KM,Chen LI,Treuting PM,Smith LT,Swisshelm K

更新日期：1999-07-20 00:00:00

abstract：:Brain function depends on adaptive self-organization of large-scale neural assemblies, but little is known about quantitative network parameters governing these processes in humans. Here, we describe the topology and synchronizability of frequency-specific brain functional networks using wavelet decomposition of magne...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bassett DS,Meyer-Lindenberg A,Achard S,Duke T,Bullmore E

更新日期：2006-12-19 00:00:00

abstract：:An ADP analog carrying a biotin moiety and a photoreactive group was synthesized. In the presence of vanadate ion (Vi), the analog was tightly trapped into the ATPase site of heavy meromyosin (HMM) or myosin subfragment 1 (S1) in an ADP analog/ATPase site molar ratio of 1:1. UV illumination on the HMM (or S1)-Vi-ADP a...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sutoh K,Yamamoto K,Wakabayashi T

更新日期：1986-01-01 00:00:00

abstract：:Plasma levels of corticosterone are often used as a measure of "stress" in wild animal populations. However, we lack conclusive evidence that different stress levels reflect different survival probabilities between populations. Galápagos marine iguanas offer an ideal test case because island populations are affected d...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Romero LM,Wikelski M

更新日期：2001-06-19 00:00:00

abstract：:Motion detection is typically spared in blindsight, which results from damage to the striate cortex (area V1) of the brain that is sufficient to eliminate conscious visual awareness and severely reduce sensitivity to luminance contrast, especially for high spatial and low temporal frequencies. Here we show that the di...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Azzopardi P,Hock HS

更新日期：2011-01-11 00:00:00

abstract：:Echoviruses are enteroviruses that belong to Picornaviridae. Many echoviruses use decay-accelerating factor (DAF) as their cellular receptor. DAF is a glycosylphosphatidyl inositol-anchored complement regulatory protein found on most cell surfaces. It functions to protect cells from complement attack. The cryo-electro...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： He Y,Lin F,Chipman PR,Bator CM,Baker TS,Shoham M,Kuhn RJ,Medof ME,Rossmann MG

更新日期：2002-08-06 00:00:00

abstract：:Clostridium kluyveri grown in the presence of 1 muM Na2(75)SeO3 produces a thiolase that copurifies with 75Se. Based on several criteria, the selenium moiety in this protein is selenomethionine. The 75Se-labeled amino acid in acid hydrolysates of the radioactive protein cochromatographed with authentic selenomethionin...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hartmanis MG,Stadtman TC

更新日期：1982-08-01 00:00:00

abstract：:Metal detoxification is essential for bacteria's survival in adverse environments and their pathogenesis in hosts. Understanding the underlying mechanisms is crucial for devising antibacterial treatments. In the Gram-negative bacterium Escherichia coli, membrane-bound sensor CusS and its response regulator CusR togeth...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fu B,Sengupta K,Genova LA,Santiago AG,Jung W,Krzemiński Ł,Chakraborty UK,Zhang W,Chen P

更新日期：2020-06-16 00:00:00

abstract：:The RNA world hypothesis presumes that RNA will be competent for varied essential cellular functions. One such indispensable cell function is regulation of membrane permeability. Though this was not a known RNA activity, selection-amplification yielded RNAs that bound phosphatidylcholine:cholesterol liposomes. At leas...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Khvorova A,Kwak YG,Tamkun M,Majerfeld I,Yarus M

更新日期：1999-09-14 00:00:00