Abstract:
:The rat anterior pituitary gland (AP) receives all of its blood supply via the hypophyseal portal circulation. We now report, in rats with estradiol (E2)-induced prolactin-secreting tumors, that newly formed arteries directly supply the AP and that this arteriogenesis is closely correlated with the sensitivity of two strains of rats to the tumorigenic action of E2. Fischer 344 rats, a strain extremely sensitive to E2, and Sprague-Dawley rats, a less sensitive strain, were ovariectomized and implanted with E2-filled or empty Silastic capsules. Ten to 63 days later, microspheres (15 microns) were injected into the heart. Normally microspheres do not reach the AP because they are trapped in the primary portal capillary plexus. Some animals were also perfused with vascular cast material. In Fischer rats, after 63 days of E2, the pituitary weight, serum prolactin, and number of microspheres in the AP were 5-, 42-, and 18-fold greater than control values, respectively. The same parameters in E2-treated Sprague-Dawley rats were 2-, 27-, and 7-fold greater than control values. Vascular casts from E2-treated Fischer rats revealed numerous arteries entering the AP. No arteries to the AP were observed in Sprague-Dawley controls. These results show that E2-induced tumorigenesis of the AP is associated with the development of a direct arterial blood supply. We hypothesize that the regions supplied by these new arteries would receive systemic blood containing subphysiological concentrations of dopamine. The loss of dopaminergic inhibition in concert with E2 stimulation may lead to tumor formation.
journal_name
Proc Natl Acad Sci U S Aauthors
Elias KA,Weiner RIdoi
10.1073/pnas.81.14.4549subject
Has Abstractpub_date
1984-07-01 00:00:00pages
4549-53issue
14eissn
0027-8424issn
1091-6490journal_volume
81pub_type
杂志文章abstract::The biosynthesis of beta-nerve growth factor (betaNGF) was studied in mouse submaxillary glands incubated with L-[(35)S]cystine. betaNGF was isolated from tissue extracts by the addition of antiserum against betaNGF and the washed immunoprecipitates were analyzed by sodium dodecyl sulfate gel electrophoresis. With sho...
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.74.9.3647
更新日期:1977-09-01 00:00:00
abstract::The unfolded protein response (UPR) is an evolutionarily conserved mechanism by which all eukaryotic cells adapt to the accumulation of unfolded proteins in the endoplasmic reticulum (ER). Inositol-requiring kinase 1 (IRE1) and PKR-related ER kinase (PERK) are two type I transmembrane ER-localized protein kinase recep...
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.0606480103
更新日期:2006-09-26 00:00:00
abstract::Grasslands cover more than 20% of the Earth's terrestrial surface, and their rise to dominance is one of the most dramatic events of biome evolution in Earth history. Grasses possess two main photosynthetic pathways: the C(3) pathway that is typical of most plants and a specialized C(4) pathway that minimizes photores...
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.0909672107
更新日期:2010-02-09 00:00:00
abstract::The possible role of guanosine 5'-triphosphate,3'-diphosphate (pppGpp) in protein synthesis by Escherichia coli ribosomes and protein factors was examined. Although pppGpp could effectively substitute for GTP in reactions catalyzed by initiation factor 2 (ribosomal binding of fMet-tRNA and formation of N-formylmethion...
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.70.11.3250
更新日期:1973-11-01 00:00:00
abstract::Alzheimer's disease (AD) comprises multifactorial ailments for which current therapeutic strategies remain insufficient to broadly address the underlying pathophysiology. Epigenetic gene regulation relies upon multifactorial processes that regulate multiple gene and protein pathways, including those involved in AD. We...
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.1707544114
更新日期:2017-10-24 00:00:00
abstract::Intracellular transport is based on molecular motors that pull cargos along cytoskeletal filaments. One motor species always moves in one direction, e.g., conventional kinesin moves to the microtubule plus end, whereas cytoplasmic dynein moves to the microtubule minus end. However, many cellular cargoes are observed 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.0706825105
更新日期:2008-03-25 00:00:00
abstract::Serum from a patient (CO) with acute lymphoblastic leukemia was reactive in immunoadherence assays with autologous leukemia cells but not with autologous blood lymphocytes or bone marrow cells during complete remission. Extensive absorption tests with an array of leukemia cells and normal cells were performed in order...
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.80.8.2341
更新日期:1983-04-01 00:00:00
abstract::A physical map of the 9.2-Mbp Myxococcus xanthus DK1622 chromosome at a resolution of 25 kbp was constructed by using a strategy that is applicable to virtually all microorganisms. Segments of the chromosome were used as hybridization probes to subdivide a yeast artificial chromosome (YAC) library into groups of linke...
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.91.20.9584
更新日期:1994-09-27 00:00:00
abstract::Recent theory and field observations suggest that a systematically varying weathering zone, that can be tens of meters thick, commonly develops in the bedrock underlying hillslopes. Weathering turns otherwise poorly conductive bedrock into a dynamic water storage reservoir. Infiltrating precipitation typically will pa...
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.1800141115
更新日期:2018-03-13 00:00:00
abstract::Specific rearrangement of internal chromosomal regions occurs during development of the somatic macronucleus in Tetrahymena thermophila and results in elimination of germ-line (micronuclear) DNA sequences. The timing and mechanism of genome rearrangement within one particular 9.3-kilobase region, which contains three ...
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.81.23.7383
更新日期:1984-12-01 00:00:00
abstract::The noninvasive detection and quantification of CD8(+) T cells in vivo are important for both the detection and staging of CD8(+) lymphomas and for the monitoring of successful cancer immunotherapies, such as adoptive cell transfer and antibody-based immunotherapeutics. Here, antibody fragments are constructed to targ...
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.1316922111
更新日期:2014-01-21 00:00:00
abstract::Vascular endothelial growth factor C (VEGF-C) recently has been described to be a relatively specific growth factor for the lymphatic vascular system. Here we report that ectopic application of recombinant VEGF-C also has potent angiogenic effects in vivo. VEGF-C is sufficiently potent to stimulate neovascularization ...
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.95.24.14389
更新日期:1998-11-24 00:00:00
abstract::Precipitates of hemoglobin, termed Heinz bodies, occur in a fraction of erythrocytes after removal of the spleen and are also observed in aged erythrocytes. This implies that precipitates of hemoglobin might play a particular role in senescent cell recognition. By using immunofluorescence microscopy, evidence is prese...
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.83.16.6137
更新日期:1986-08-01 00:00:00
abstract::It is generally believed that serial passage at high multiplicity of infection (moi) is required for the generation of defective interfering (DI) particles. High levels of DI RNAs are found associated with persistent infections initiated with laboratory cultures of cucumber necrosis virus (CNV). Two synthetic CNV tran...
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.88.24.11153
更新日期:1991-12-15 00:00:00
abstract::Treatment of 45Ca2+-loaded GH3 pituitary cells with various concentrations of digitonin revealed discrete pools (I and II) of cellular 45Ca2+ defined by differing detergent sensitivities. Markers for cytosol and intracellular organelles indicated that the two 45Ca2+ pools were correlated with the two major cellular Ca...
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.79.20.6294
更新日期:1982-10-01 00:00:00
abstract::Understanding the mechanisms by which compounds discovered using cell-based phenotypic screening strategies might exert their effects would be highly augmented by new approaches exploring their potential interactions with the genome. For example, altered androgen receptor (AR) transcriptional programs, including castr...
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.1404303111
更新日期:2014-06-24 00:00:00
abstract::When grafting or wounding disconnects stem tissues, new tissues are generated to restore the lost connection. In this study, the molecular mechanism of such healing was elucidated in injured stems of Arabidopsis. Soon after the inflorescence stems were incised, the pith cells started to divide. This process was strong...
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.1110443108
更新日期:2011-09-20 00:00:00
abstract::Mutations are a hallmark of cancer. Normal cells minimize spontaneous mutations through the combined actions of polymerase base selectivity, 3' --> 5' exonucleolytic proofreading, mismatch correction, and DNA damage repair. To determine the consequences of defective proofreading in mammals, we created mice with a poin...
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.232340999
更新日期:2002-11-26 00:00:00
abstract::Neuropeptide B (NPB) and neuropeptide W (NPW) have been recently identified as ligands for the G protein-coupled receptor (GPR) 7 and GPR8. The precise in vivo role of this neuropeptide-receptor pathway has not been fully demonstrated. In this paper, we report that NPB-deficient mice manifest a mild adult-onset obesit...
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.0503795102
更新日期:2005-07-12 00:00:00
abstract::Tryptophan biosynthesis is subject to exquisite control in species of Bacillus and has become one of the best-studied model systems in gene regulation. The protein TRAP (trp RNA-binding attenuation protein) predominantly forms a ring-shaped 11-mer, which binds cognate RNA in the presence of tryptophan to suppress expr...
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.0801032106
更新日期:2009-02-17 00:00:00
abstract::Extreme animal movements are usually associated with a single, high-performance behavior. However, the remarkably rapid mandible strikes of the trap-jaw ant, Odontomachus bauri, can yield multiple functional outcomes. Here we investigate the biomechanics of mandible strikes in O. bauri and find that the extreme mandib...
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.0604290103
更新日期:2006-08-22 00:00:00
abstract::Programmed cell death regulates a number of biological phenomena, and the apoptotic signal must itself be tightly controlled to avoid inappropriate cell death. We established a genetic screen to search for molecules that inhibit the apoptotic signal from the Fas receptor. Here we report the isolation of a gene, LFG, 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.96.22.12667
更新日期:1999-10-26 00:00:00
abstract::Smooth muscle cells use fibronectin to bind to type I and type III collagens but bind to type V collagen by a trypsin-resistant intrinsic glycoconjugate. The binding site on type V collagen is located in the alpha A chain. By using collagen-coated filters in a modified Boyden chamber assay for chemotaxis, it was obser...
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.78.6.3669
更新日期:1981-06-01 00:00:00
abstract::A series of anti-human placental uracil DNA glycosylase monoclonal antibodies was used to screen a human placental cDNA library in phage lambda gt11. Twenty-seven immunopositive plaques were detected and purified. One clone containing a 1.2-kilobase (kb) human cDNA insert was chosen for further study by insertion into...
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.86.22.8693
更新日期:1989-11-01 00:00:00
abstract::Cellular differentiation leading to formation of the bradyzoite tissue cyst stage is the underlying cause of chronic toxoplasmosis. Consequently, mechanisms responsible for controlling development in the Toxoplasma intermediate life cycle have long been sought. Here, we identified 15 Toxoplasma mRNAs induced in early ...
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.1300059110
更新日期:2013-04-23 00:00:00
abstract::Replication-competent viruses, such as Vaccinia virus (VACV), are powerful tools for the development of oncolytic viral therapies and elicit superior immune responses when used as vaccine and immunotherapeutic vectors. However, severe complications from uncontrolled viral replication can occur, particularly in immunoc...
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.1314483110
更新日期:2013-09-17 00:00:00
abstract::Telomerase activity was identified in extracts from several different mouse cell lines. Addition of telomeric TTAGGG repeats was specific to telomeric oligonucleotide primers and sensitive to pretreatment with RNase A. In contrast to the hundreds of repeats synthesized by the human and Tetrahymena telomerase enzymes i...
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.90.4.1493
更新日期:1993-02-15 00:00:00
abstract::The thin layer of airway surface liquid (ASL) contains antimicrobial substances that kill the small numbers of bacteria that are constantly being deposited in the lungs. An increase in ASL salt concentration inhibits the activity of airway antimicrobial factors and may partially explain the pathogenesis of cystic fibr...
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.97.21.11614
更新日期:2000-10-10 00:00:00
abstract::The oncoproteins MDM2 and MDMX negatively regulate the activity and stability of the tumor suppressor protein p53--a cellular process initiated by MDM2 and/or MDMX binding to the N-terminal transactivation domain of p53. MDM2 and MDMX in many tumors confer p53 inactivation and tumor survival, and are important molecul...
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.0900947106
更新日期:2009-03-24 00:00:00
abstract::Mice carrying mutations in either the dominant white-spotting (W) or Steel (Sl) loci exhibit deficits in melanogenesis, gametogenesis, and hematopoiesis. W encodes the Kit receptor tyrosine kinase, while Sl encodes the Kit ligand, Steel factor, and the receptor-ligand pair are contiguously expressed at anatomical site...
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.93.5.1808
更新日期:1996-03-05 00:00:00