Abstract:
:Techniques of fluorescence and ion microscopies were combined to study the free [Ca2+] and total Ca in NIH 3T3 fibroblast and L6 rat myoblast cells. Free Ca2+ measurements with the Ca2+ indicator fura-2 and digital imaging reveal an inhomogeneous distribution of free cytoplasmic Ca2+ in both cell lines. Fura-2 also reveals a difference in free Ca2+ activity between the nucleus and cytoplasm of cells. Ion microscopic observations on sister cells show that total Ca in the cytoplasm is also inhomogeneously distributed and that mean cytoplasmic levels of total Ca are higher than levels in the nuclei. In the nuclei of NIH 3T3 cells, the mean free [Ca2+] and total [Ca] were 110 +/- 30 nM and 225 +/- 43 microM, respectively, while regions in the cell cytoplasm contained up to 490 +/- 270 nM free [Ca2+] and 559 +/- 184 microM mean total [Ca]. Intracellular total Ca was greater than 3 orders of magnitude higher than intracellular free Ca2+ in either nuclear or cytoplasmic compartments. Perinuclear cytoplasmic regions in 3T3 cells contained higher free and total Ca than the cell nucleus. Loading of cells with fura-2 did not modify the subcellular distribution of total K, Na, Ca, or Mg. This combination of two powerful ion imaging techniques provides a comparison between free and total calcium in cells and introduces a different approach for examining the role of this important element in cell physiology.
journal_name
Proc Natl Acad Sci U S Aauthors
Chandra S,Gross D,Ling YC,Morrison GHdoi
10.1073/pnas.86.6.1870subject
Has Abstractpub_date
1989-03-01 00:00:00pages
1870-4issue
6eissn
0027-8424issn
1091-6490journal_volume
86pub_type
杂志文章abstract::We demonstrate remote detection of nuclear magnetic resonance (NMR) with a microchip sensor consisting of a microfluidic channel and a microfabricated vapor cell (the heart of an atomic magnetometer). Detection occurs at zero magnetic field, which allows operation of the magnetometer in the spin-exchange relaxation-fr...
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.0711505105
更新日期:2008-02-19 00:00:00
abstract::Quaking(viable) (qk(v)) is a recessive neurological mouse mutation with severe dysmyelination of the CNS and spermiogenesis failure. The molecular lesion in the qk(v) mutant is a deletion of approximately 1 Mb on mouse chromosome 17 that alters the expression of the qk gene in oligodendrocytes. Complementation analysi...
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.0401832101
更新日期:2004-06-01 00:00:00
abstract::Short interfering RNA (siRNA) is widely used for studying gene function and holds great promise as a tool for validating drug targets and treating disease. A critical assumption in these applications is that the effect of siRNA on cells is specific, i.e., limited to the specific knockdown of the target gene. In this a...
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更新日期:2003-05-27 00:00:00
abstract::Bloom syndrome is a disorder of profound and early cancer predisposition in which cells become hypermutable, exhibit high frequency of sister chromatid exchanges, and show increased micronuclei. BLM, the gene mutated in Bloom syndrome, has been cloned previously, and the BLM protein is a member of the RecQ family of D...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::Natural environments typically contain multiple sound sources. The sounds from these sources frequently overlap in time and often mask each other. Masking could potentially distort the representation of a sound's spectrum, altering its timbre and impairing object recognition. Here, we report that the auditory system p...
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.0711291105
更新日期:2008-04-15 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2006-05-02 00:00:00
abstract::LTRs of endogenous retroviruses are known to affect expression of several human genes, typically as a relatively minor alternative promoter. Here, we report that an endogenous retrovirus LTR acts as one of at least two alternative promoters for the human beta1,3-galactosyltransferase 5 gene, involved in type 1 Lewis a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2003-10-28 00:00:00
abstract::Exposure of murine hepatoma (Hepa 1c1c7) cells to a variety of chemical agents known to protect animals against the neoplastic, mutagenic, and other toxic effects of chemical carcinogens results in dose- and time-dependent inductions of NAD(P)H:quinone reductase (EC 1.6.99.2). This enzyme protects against quinone toxi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1986-02-01 00:00:00
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pub_type: 杂志文章,评审
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更新日期:2006-09-05 00:00:00
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更新日期:1984-11-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.1305209110
更新日期:2013-04-23 00:00:00
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doi:10.1073/pnas.73.1.64
更新日期:1976-01-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1982-07-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2004-02-03 00:00:00
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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.1922618117
更新日期:2020-10-20 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1989-12-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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pub_type: 临床试验,杂志文章,随机对照试验
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更新日期:1995-02-14 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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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.94.21.11393
更新日期:1997-10-14 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2014-07-15 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2005-03-22 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2006-10-31 00:00:00
abstract::The human immunodeficiency virus type 1 (HIV-1) trans-activator protein, Tat, specifically stimulates transcription from the viral long terminal repeat. Tat binds to an RNA stem-loop structure encoded by the trans-activation response region (TAR). To test whether TAR is functional when displaced downstream of the star...
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.92.6.2408
更新日期:1995-03-14 00:00:00
abstract::Directionality of signaling among brain regions provides essential information about human cognition and disease states. Assessing such effective connectivity (EC) across brain states using functional magnetic resonance imaging (fMRI) alone has proven difficult, however. We propose a novel measure of EC, termed metabo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2016-01-12 00:00:00
abstract::Malaria control is threatened by a limited pipeline of effective pharmaceuticals against drug-resistant strains of Plasmodium falciparum Components of the mitochondrial electron transport chain (ETC) are attractive targets for drug development, owing to exploitable differences between the parasite and human ETC. Disru...
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.1804492115
更新日期:2018-06-12 00:00:00