Abstract:
:A biologically active vitamin D(3) metabolite ("peak V metabolite") more polar than 25-hydroxycholecalciferol has been isolated from chicken intestines in pure form as a mono(trimethylsilyl)ether derivative. The molecule has been identified as 1,25-dihydroxycholecalciferol by means of mass spectrometry, ultraviolet absorption spectrophotometry, and specific chemical reactions.
journal_name
Proc Natl Acad Sci U S Aauthors
Holick MF,Schnoes HK,DeLuca HFdoi
10.1073/pnas.68.4.803subject
Has Abstractpub_date
1971-04-01 00:00:00pages
803-4issue
4eissn
0027-8424issn
1091-6490journal_volume
68pub_type
杂志文章abstract::In 2009 we reported that depletion of Dicer-1, the enzyme that catalyzes the final step of miRNA biosynthesis, prevents metamorphosis in Blattella germanica. However, the precise regulatory roles of miRNAs in the process have remained elusive. In the present work, we have observed that Dicer-1 depletion results in an ...
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.1418522112
更新日期:2015-03-24 00:00:00
abstract::A somatic hybrid of ASL-1 leukemia cells [H-2a, thymus leukemia (TL)1,2,3, Thy-1b] and LM(TK)-cells [H-2-k, TL(-), Thy-1 (-), thymidine kinase deficient] was formed with the aid of inactivated Sendai virus. The selection of hybrid cell clones was facilitated by the inability of ASL-1 cells to grow in vitro and of LM(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.72.5.1873
更新日期:1975-05-01 00:00:00
abstract::Hydrogenases catalyze the reversible reaction 2H(+) + 2e(-) ↔ H(2) with an equilibrium constant that is dependent on the reducing potential of electrons carried by their redox partner. To examine the possibility of increasing the photobiological production of hydrogen within cyanobacterial cultures, we expressed the [...
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.1016026108
更新日期:2011-03-08 00:00:00
abstract::Long-term, localized delivery of small molecules from a biodegradable thin film is challenging owing to their low molecular weight and poor charge density. Accomplishing highly extended controlled release can facilitate high therapeutic levels in specific regions of the body while significantly reducing the toxicity 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.1323829111
更新日期:2014-08-19 00:00:00
abstract::Activation of the MEK/ERK/Elk-signaling cascade is a mechanism for relaying mitogenic and stress stimuli for gene activation. MEK1 is the proximate kinase for activation of ERK1/2, and nuclear targeting of ERK1/2 is obligatory for Elk1 transcriptional activity. Human biliverdin reductase (hBVR) is a recently described...
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.0800750105
更新日期:2008-05-13 00:00:00
abstract::A detailed model of the G(2) DNA damage checkpoint (G2DDC) system is presented that includes complex regulatory networks of the mitotic kinase Cdc2, phosphatase Cdc25, Wee1 kinase, and damage signal transduction pathways involving Chk1 and p53. Assumptions on the kinetic equations of the G2DDC are made, and computer s...
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.96.20.11352
更新日期:1999-09-28 00:00:00
abstract::An expression vector containing the murine c-ets-2 protooncogene cDNA was introduced into NIH 3T3 cells by DNA transfection. The cells transfected with this construct showed foci of densely growing, morphologically altered cells, when grown either in low-serum (0.05%) or in serum-free medium. The c-ets-2-derived foci ...
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.86.20.7833
更新日期:1989-10-01 00:00:00
abstract::A7r5 smooth muscle (aorta) cells have a spontaneous electrical activity. Application of vasopressin produces a hyperpolarization accompanied by an interruption of the spontaneous activity, which is followed by a depolarization associated with a recovery of the spiking activity. Vasopressin action is produced by an act...
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.85.23.9365
更新日期:1988-12-01 00:00:00
abstract::Thiazides and related diuretics inhibit NaCl reabsorption in the distal tubule through an unknown mechanism. We report here that [3H]metolazone, a diuretic with a thiazide-like mechanism of action, labels a site in rat kidney membranes that has characteristics of the thiazide-sensitive ion transporter. [3H]Metolazone ...
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.85.7.2311
更新日期:1988-04-01 00:00:00
abstract::The mouse adipsin gene encodes a member of the serine protease family that is expressed predominantly in adipose tissue and is secreted into the bloodstream. Adipsin expression is sharply down-regulated in several models of genetic and acquired obesity, representing the first example of an adipocyte gene whose express...
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.86.19.7490
更新日期:1989-10-01 00:00:00
abstract::Kinesin-73 cDNA was shown to encode a kinesin heavy chain protein that contains an N-terminal motor domain and a long central region that lacks extensive coiled-coils. The amino acid sequence of the motor domain of kinesin-73 protein is most closely related to the motor domains of Caenorhabditis elegans unc-104 and mo...
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.94.4.1086
更新日期:1997-02-18 00:00:00
abstract::The onset of autoimmunity in experimental rodent models and patients frequently correlates with a lymphopenic state. In this condition, the immune system has evolved compensatory homeostatic mechanisms that induce quiescent naive T cells to proliferate and differentiate into memory-like lymphocytes even in the apparen...
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.0807743105
更新日期:2008-12-09 00:00:00
abstract::Cultured hippocampal slices prepared from apolipoprotein E-deficient mice were exposed to an inhibitor of cathepsins B and L and then processed for immunocytochemistry using antibodies against human paired helical filaments. Dense, AT8-immunopositive deposits were found in the subiculum, stratum oriens of hippocampal ...
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.151253098
更新日期:2001-07-17 00:00:00
abstract::The tissue-specific transcriptional coactivator OCA-B is required for antigen-dependent B cell differentiation events, including germinal center formation. However, the identity of OCA-B target genes involved in this process is unknown. This study has used large-scale cDNA arrays to monitor changes in gene expression ...
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.1033108100
更新日期:2003-07-22 00:00:00
abstract::Both naturally occurring and synthetic phosphatidic acid (PtdOH) molecules show the phenomenon of spontaneous vesiculation on jump in pH value. This method involves a transient increase in pH of smectic PtdOH dispersions to values between 10 and 12. Such a pH increase induces spontaneous vesiculation with the formatio...
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.86.14.5351
更新日期:1989-07-01 00:00:00
abstract::A Ca2+-channel blocker derived from funnel-web spider toxin (FTX) has made it possible to define and study the ionic channels responsible for the Ca2+ conductance in mammalian Purkinje cell neurons and the preterminal in squid giant synapse. In cerebellar slices, FTX blocked Ca2+-dependent spikes in Purkinje cells, re...
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.86.5.1689
更新日期:1989-03-01 00:00:00
abstract::Amino-terminal sequence determinations are reported of the subunits of biliproteins of prokaryotic unicellular and filamentous cyanobacteria and of eukaryotic unicellular red algae. The biliproteins examined, allophycocyanin, C-phycocyanin, R-phycocyanin, b-phycoerythrin, and phycoerythrocyanin, vary with respect to 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.73.2.428
更新日期:1976-02-01 00:00:00
abstract::Retinal dopaminergic amacrine neurons (DA neurons) play a central role in reconfiguring retinal function according to prevailing illumination conditions, yet the mechanisms by which light regulates their activity are poorly understood. We investigated the means by which sustained light responses are evoked in DA neuro...
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.0803893105
更新日期:2008-09-16 00:00:00
abstract::The antigenic sites of horse and rat cytochromes c in the major antigenic region were compared using a panel of variant cytochromes c and a large number of BALB/c mouse monoclonal antibodies (mAbs) in competitive ELISAs. The major antigenic region of cytochrome c is located on the surface opposite of that containing 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.88.10.4428
更新日期:1991-05-15 00:00:00
abstract::Forests and their soils contain the majority of the earth's terrestrial carbon stocks. Changes in patterns of tree growth can have a huge impact on atmospheric cycles, biogeochemical cycles, climate change, and biodiversity. Recent studies have shown increases in biomass across many forest types. This increase has bee...
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.0912376107
更新日期:2010-02-23 00:00:00
abstract::Mammalian DAI (DNA-dependent activator of IFN-regulatory factors), an activator of the innate immune response, senses cytosolic DNA by using 2 N-terminal Z-DNA binding domains (ZBDs) and a third putative DNA binding domain located next to the second ZBD. Compared with other previously known ZBDs, the second ZBD of hum...
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.0810463106
更新日期:2008-12-30 00:00:00
abstract::Evidence based on a study of alanine-resistant (Alar), constitutive mutants of CHO-K1 cells and the conditions that favor stimulation of the A system of amino acid activity supports the model that the A system of amino acid transport in these cells is repressible and under negative control of regulatory gene R1. 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.84.22.8040
更新日期:1987-11-01 00:00:00
abstract::Maximum likelihood analysis for linkage between autosomal dominant aniridia and 12 biochemical and serological markers in a single large family showed a probable linkage between autosomal dominant aniridia and the enzyme acid phosphatase-1. The presence of an autosomal dominant aniridia gene linked to acid phosphatase...
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.77.3.1580
更新日期:1980-03-01 00:00:00
abstract::The mouse mammary tumor virus (MMTV) promoter is regulated by steroid hormones through a hormone-responsive region that is organized in a positioned nucleosome. Hormone induction leads to a structural change of this nucleosome which makes its DNA more sensitive to cleavage by DNase I and enables simultaneous binding 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.93.20.10741
更新日期:1996-10-01 00:00:00
abstract::Considerable effort has been directed toward controlling tuberculosis, which kills almost two million people yearly. High on the research agenda is the discovery of biomarkers of active tuberculosis (TB) for diagnosis and for monitoring treatment outcome. Rational biomarker discovery requires understanding host-pathog...
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.1009080107
更新日期:2010-08-17 00:00:00
abstract::Complement receptors (CRs), expressed notably on myeloid and lymphoid cells, play an essential function in the elimination of complement-opsonized pathogens and apoptotic/necrotic cells. In addition, these receptors are crucial for the cross-talk between the innate and adaptive branches of the immune system. CR3 (also...
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.1311261110
更新日期:2013-10-08 00:00:00
abstract::A comparison of the monoclinic and orthorhombic crystal structures of the uncomplexed double-stranded, antiparallel, left-handed beta-helix (5.6 amino acid residues per turn) (increases decreases beta 5.6) conformers of gramicidin A reveals marked differences in the tryptophan side-chain orientations and the degree of...
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.88.12.5345
更新日期:1991-06-15 00:00:00
abstract::Mammalian reproductive function depends upon a neuroendocrine circuit that evokes the pulsatile release of gonadotropin hormones (luteinizing hormone and follicle-stimulating hormone) from the pituitary. This reproductive circuit is sensitive to metabolic perturbations. When challenged with starvation, insufficient en...
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.1621065114
更新日期:2017-02-28 00:00:00
abstract::Natural environments are filled with multiple, often competing, signals. In contrast, biological systems are often studied in "well-controlled" environments where only a single input is varied, potentially missing important interactions between signals. Catabolite repression of galactose by glucose is one of the best-...
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.1418058112
更新日期:2015-02-03 00:00:00
abstract::Evidence is presented for two natural transcription initiators positioned internally in the histidine operon of Salmonella typhimurium. They were detected using highly polar S. typhimurium his mutants as recipients for F' Escherichia coli his episomes. These intergeneric complementation tests provide a sensitive metho...
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.65.4.925
更新日期:1970-04-01 00:00:00