Abstract：
:Normal mammary epithelial cells from BALB/cfC3H midpregnant mice were freed from stromal cell types by Percoll density gradient centrifugation after collagenase digestion and were then embedded within collagen gels. Sustained growth leading to an increase in cell number was accomplished in response to cholera toxin and high concentrations of horse serum. The extent of growth was found to be dependent on the horse serum concentration, the maximum growth being attained at 50%. A serum concentration of 12.5% horse serum and 2.5% fetal calf serum, along with cholera toxin at 0.01 mug/ml, allowed maintenance but failed to cause any significant increase in cell number during the experimental period of 2 weeks. This same maintenance medium was used to determine the effects of various exogenously added steroids, protein hormones, and organ extracts on the proliferation of mammary epithelial cells in culture. Hormones failed to elicit any proliferative response, but extracts of kidney, brain, uterus, and spleen produced proliferative responses equal to or greater than the response obtained with 50% horse serum and cholera toxin. Kidney extracts prepared from midpregnant mice, virgin mice, and virgin mice given pituitary isografts all showed comparable activities, suggesting that the concentration of stimulatory factor(s) was not influenced by the hormonal status of the donor. Normal mammary epithelial cells that had undergone a 10- to 15-fold increase in cell number over initial values during 2-3 weeks in culture were passaged to secondary gel cultures. Outgrowth similar to those seen in primary culture were seen again in secondary culture. The present system provides a method for sustaining growth in culture of primary mammary epithelial cells from normal tissues.
journal_name
Proc Natl Acad Sci U S Aauthors
Yang J,Richards J,Guzman R,Imagawa W,Nandi Sdoi
10.1073/pnas.77.4.2088subject
Has Abstractpub_date
1980-04-01 00:00:00pages
2088-92issue
4eissn
0027-8424issn
1091-6490journal_volume
77pub_type
杂志文章abstract：:Stromal cell lines were established from canine long-term marrow cultures, cloned by limiting dilution, and maintained in stromal cell-conditioned medium. These cells grew adherent, maintained stable growth rate and morphology under standard conditions (in 20-30% conditioned medium; confluency, 70-90%), and supported ...
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.92.3.748
更新日期：1995-01-31 00:00:00
abstract：:Small solutes affect protein and nucleic acid processes because of favorable or unfavorable chemical interactions of the solute with the biopolymer surface exposed or buried in the process. Large solutes also exclude volume and affect processes where biopolymer molecularity and/or shape changes. Here, we develop an 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.1103382108
更新日期：2011-08-02 00:00:00
abstract：:A retinoid was isolated by a multistep procedure from the small intestines of vitamin A-deficient rats given a single dose of retinoic acid. The compound, designated 8II, was pure, as demonstrated by four high-pressure liquid chromatographic procedures. It was positively identified as 5,8-oxyretinoic acid by ultraviol...
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.75.6.2603
更新日期：1978-06-01 00:00:00
abstract：:The potent muscarinic photoaffinity reagent N-methyl-4-piperidyl p-azidobenzilate (azido-4NMPB) was used to covalently label specific muscarinic binding sites in various brain regions and in the heart. In the cortex and hippocampus, a single specifically labeled protein with an apparent molecular mass of 86,000 dalton...
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.80.1.156
更新日期：1983-01-01 00:00:00
abstract：:P2X receptors for ATP have a wide range of physiological roles and comprise a structurally distinct family of ligand-gated trimeric ion channels. The crystal structure of a P2X4 receptor, in combination with mutagenesis studies, has provided a model of the intersubunit ATP-binding sites and identified an extracellular...
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.1201872109
更新日期：2012-03-20 00:00:00
abstract：:Estradiol-17beta administration to young (10- to 12-week-old) rabbits to produce the "estrogen-dominated" uterus increased the uterine contractile response to both oxytocin and methacholine in vitro. In "progesterone-dominated" uteri, obtained from rabbits that received progesterone for 4 days after estrogen pretreatm...
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.75.4.2044
更新日期：1978-04-01 00:00:00
abstract：:The tumor suppressor Smad4/Dpc4 is a transcription activator that binds specific DNA sequences and whose nuclear localization is induced after exposure to type beta transforming growth factor-like cytokines. We explored an inducible system in which Smad4 protein is activated by translocation to the nucleus when cell l...
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.96.4.1427
更新日期：1999-02-16 00:00:00
abstract：:Guanylyl cyclase C (GCC) has been detected only in intestinal mucosa and colon carcinoma cells of placental mammals. However, this receptor has been identified in several tissues in marsupials, and its expression has been suggested in tissues other than intestine in placental mammals. Selective expression of GCC by co...
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.93.25.14827
更新日期：1996-12-10 00:00:00
abstract：:When an unusually high frequency of an allele is encountered in a population, "founder effect" is often invoked as an explanation. As usually used, the term implies the disproportionate increase through chance (rather than selection) of an allele contributed to the population by a particular ancestor. While genetic 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.75.3.1442
更新日期：1978-03-01 00:00:00
abstract：:Autism spectrum disorder (ASD) is characterized by impaired social interactions and communication. The pathogenesis of ASD is not known, but it involves activation of microglia. We had shown that the peptide neurotensin (NT) is increased in the serum of children with ASD and stimulates cultured adult human microglia 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.2004666117
更新日期：2020-07-14 00:00:00
abstract：:With the completion of genome sequences of major model organisms, increasingly sophisticated genetic tools are necessary for investigating the complex and coordinated functions of genes. Here we describe a genetic manipulation system termed "genomic engineering" in Drosophila. Genomic engineering is a 2-step process 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.0900641106
更新日期：2009-05-19 00:00:00
abstract：:The growth of 3T3 and SV101 3T3 cells in a lipid-depleted medium is enhanced by the addition of biotin or some fatty acids. The extent of enhancement depends on the fatty acid(s) supplied. The presence of linoleate is unique, since it induces a morphological alteration in 3T3 cells resulting in a cell similar to an SV...
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.71.8.3115
更新日期：1974-08-01 00:00:00
abstract：:The P23T mutant of human gammaD-crystallin (HGD) is associated with cataract. We have previously investigated the solution properties of this mutant, as well as those of the closely related P23V and P23S mutants, and shown that although mutations at site 23 of HGD do not produce a significant structural change in 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.0707412104
更新日期：2007-10-23 00:00:00
abstract：:Growth hormone (GH) has previously been implicated in T-cell development, and here we test its efficacy in promoting T-lymphocyte engraftment in mice with severe combined immune deficiency (SCID). SCID mice receiving syngeneic thymocytes and treated with recombinant human GH (rhGH) had significantly better T-cell engr...
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.89.10.4481
更新日期：1992-05-15 00:00:00
abstract：:The virB operon of the Agrobacterium tume-faciens pTiA6NC plasmid likely plays a role in directing T-DNA transfer events at the bacterial membrane, as determined previously by mutagenesis and cellular fractionation studies and by DNA sequence analysis of the approximately 12-kilobase-pair operon. The DNA sequence anal...
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.86.24.9677
更新日期：1989-12-01 00:00:00
abstract：:The retroviral integrase protein (IN) is responsible for catalyzing a concerted integration reaction in which the two termini of linear viral DNA are joined to host DNA. To probe the potential for IN to form protein multimers, we used the yeast two-hybrid system. The coexpression of a GAL4 DNA binding domain-IN fusion...
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.90.22.10593
更新日期：1993-11-15 00:00:00
abstract：:The Bam complex assembles β-barrel proteins into the outer membrane (OM) of Gram-negative bacteria. These proteins comprise cylindrical β-sheets with long extracellular loops and create pores to allow passage of nutrients and waste products across the membrane. Despite their functional importance, several questions 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.1616576114
更新日期：2017-03-07 00:00:00
abstract：:PdxB (erythronate 4-phosphate dehydrogenase) is expected to be required for synthesis of the essential cofactor pyridoxal 5'-phosphate (PLP) in Escherichia coli Surprisingly, incubation of the ∆pdxB strain in medium containing glucose as a sole carbon source for 10 d resulted in visible turbidity, suggesting that PLP ...
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.1915569116
更新日期：2019-11-26 00:00:00
abstract：:Aged rats, displaying impairments in spatial learning and memory associated with marked cellular atrophy of forebrain cholinergic neurons, received intracerebroventricular infusions of one of the four neurotrophins nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), or neurotrop...
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.91.18.8607
更新日期：1994-08-30 00:00:00
abstract：:To understand non-trivial biological functions, it is crucial to develop minimal synthetic models that capture their basic features. Here, we demonstrate a sequence-independent, reversible control of transcription and gene expression using a photosensitive nucleic acid binder (pNAB). By introducing a pNAB whose affini...
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.0904382106
更新日期：2009-07-28 00:00:00
abstract：:Learning and memory rely on dopamine and downstream cAMP-dependent plasticity across diverse organisms. Despite the central role of cAMP signaling, it is not known how cAMP-dependent plasticity drives coherent changes in neuronal physiology that encode the memory trace, or engram. In Drosophila, the mushroom body (MB)...
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.1709037115
更新日期：2018-01-16 00:00:00
abstract：:Cells of the human embryonic stem (hES) cell line H9, when cultured in the form of embryoid bodies, give rise to cells with markers of the keratinocyte of stratified squamous epithelia. Keratinocytes also form in nodules produced in scid mice by injected H9 cells; the hES-derived keratinocytes could be recovered in cu...
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.0510953103
更新日期：2006-02-07 00:00:00
abstract：:Biological carbon fixation is limited by the supply of Fe in vast regions of the global ocean. Dissolved Fe in seawater is primarily sourced from continental mineral dust, submarine hydrothermalism, and sediment dissolution along continental margins. However, the relative contributions of these three sources to the Fe...
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.1420188112
更新日期：2015-02-03 00:00:00
abstract：:Recoverin, a recently discovered member of the EF-hand superfamily of Ca(2+)-binding proteins, serves as a Ca2+ sensor in vision. The amino terminus of the protein from retinal rod cells contains a covalently attached myristoyl or related N-acyl group. We report here studies of unmyristoylated and myristoylated recomb...
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.89.23.11569
更新日期：1992-12-01 00:00:00
abstract：:Exocytosis allows the release of secretory products and the delivery of new membrane material to the plasma membrane. So far, little is known about the underlying molecular mechanism and its control in plant cells. We have used the whole-cell patch-clamp technique to monitor changes in membrane capacitance to study ex...
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.94.12.6565
更新日期：1997-06-10 00:00:00
abstract：:Serine is the only amino acid that is encoded by two disjoint codon sets so that a tandem substitution of two nucleotides is required to switch between the two sets. Previously published evidence suggests that, for the most evolutionarily conserved serines, the codon set switch occurs by simultaneous substitution 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.1615832113
更新日期：2016-11-15 00:00:00
abstract：:Transcription termination is a critical step in the control of gene expression. One of the major termination mechanisms is mediated by Rho factor that dissociates the complex mRNA-DNA-RNA polymerase upon binding with RNA polymerase. Rho promotes termination at the end of operons, but it can also terminate transcriptio...
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.1811589116
更新日期：2019-02-19 00:00:00
abstract：:Herpes simplex virus type 2 (HSV-2) DNA was treated with four restriction endonucleases (EcoRI, HincIII, Bgl II, and Xba I) and eight fragments were purified and labeled with 32P in vitro. The kinetics of renaturation of each of the fragments was measured in the presence of DNA extracted from 333-8-9, a hamster cell l...
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.77.2.880
更新日期：1980-02-01 00:00:00
abstract：:Most mammalian cell types, including endothelial cells, respond to cell swelling by activating a Cl- current termed ICl,swell, but it is not known how the physical stimulus of cell swelling is transferred to the channels underlying ICl,swell. We have investigated the precise relation between cell volume and ICl,swell ...
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.96.9.5298
更新日期：1999-04-27 00:00:00
abstract：:Transfer of organelle DNA into the nuclear genome has been significant in eukaryotic evolution, because it appears to be the origin of many nuclear genes. Most studies on organelle DNA transfer have been restricted to evolutionary events but experimental systems recently became available to monitor the process in real...
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.0400853101
更新日期：2004-06-29 00:00:00
