112,060 research outputs found
Structure and cell-specific expression of a cloned human retinol binding protein gene: the 5\'-flanking region contains hepatoma specific transcriptional signals.
No full textExtinction of Retinol-binding Protein Gene-expression In Somatic Cell-hybrids - Identification of the Target Sequences
No full textThe Retinol-Binding Protein (RBP) is expressed primarily in the liver. The regulatory elements involved in its tissue-specific expression have been identified and mapped to the 5' flanking region of the RBP gene. In this paper heterokaryons and somatic cell-hybrids have been produced and analysed in order to demonstrate that the RBP gene is subject to extinction and to identify the target sequences of this phenomenon. We show here that the gene is extinguished in fusions of hepatoma with a variety of cells of different species and embryonic lineages. The repression is not due to loss of the gene and occurs also when chromosome 10, where the gene is located, is inherited from the expressing parental cell-type. Hybrid clones were transfected with constructs carrying DNa segments of different lengths from the 5' flanking region of the RBP gene fused to a reporter gene. We demonstrate that extinction takes place also on an exogenous RBP-CAT gene, mimicking the phenomenon observed with endogenous gene in its chromosomal location. Moreover, we identify and map the target sequences of the putative extinguishing function. Our data thus show that extinction of RBP is mediated through the DNA segment that is involved in its tissue-specific expression
Detection of Cellular Retinol-binding Protein Messenger-rna In the Somatic-cells of the Rat Seminiferous Tubules
No full textStructure and cell-specific expression of a cloned human retinol binding protein gene: the 5\'-flanking region contains hepatoma specific transcriptional signals.
No full textRegulation of insulin-like-growth-factor-II gene expression in rat liver cells.
No full textThe rat insulin-like-growth-factor-(IGF)-II gene is expressed at high levels during embryonic and fetal life and at low levels in adult animals. To study the regulation of IGF-II gene expression, we analyzed the synthesis and localization of the IGF-II transcripts in cultured rat liver cells either expressing (BRL3A cells) or not expressing (BRL30E and FAO cells) the IGF-II mRNA. The IGF-II gene is transcribed at a similar rate in expressing and non-expressing cells, whereas its nuclear and cytoplasmic RNA levels are diversely distributed in the cells. IGF-II RNA is more abundant in the cytoplasmic than in the nuclear RNA fraction of BRL3A cells and is present in the nucleus but not in the cytoplasm of the FAO cells. However, both precursor and mature IGF-II nuclear RNA levels are reduced in FAO cells. Our data indicate that the IGF-II gene expression is regulated by mechanisms affecting the subcellular distribution and the abundance of the transcripts
Cellular Retinoic-acid-binding-protein and Retinol-binding-protein Messenger-rna Expression In the Cells of the Rat Seminiferous Tubules and Their Regulation By Retinoids
No full textThe levels of the mRNA corresponding to the intracellular binding proteins for retinoic acid and retinol (CRABP1 and CRBP1, respectively) were studied in primary cultures of somatic and germ cells of the rat seminiferous tubules. We show that the CRABP1 mRNA is expressed in Sertoli and germ cells and a single molecular species of mRNA is detected. CRBP1 mRNA is detected in Sertoli and peritubular cells. The regulation of the expression of both genes by retinoids was studied in Sertoli cells. CRABP1 mRNA levels are not affected by either retinoic acid or retinol, whereas both compounds positively regulate CRBP1 mRNA synthesis in a dose-dependent manner. A fivefold increase in CRBP1 mRNA levels was observed 32 - 48 h after addition of either agent. These results demonstrate that in Sertoli cells the expression of CRABP1 is not affected by retinoids, similar to the situation observed in vivo and in other in-vitro cultures. CRBP1-gene expression is, instead, induced and the variations in CRBP1-mRNA levels may regulate the intracellular concentrations of retinoids, as a response to changes in the vitamin-A nutritional status
Does the deoxyribonucleic acid shape dictate its conductivity?
No full textWe present the evolution of current-voltage characteristics measured on linear fragments of deoxyribonucleic acid (DNA) molecules as a function of their length. The nonlinear behavior systematically observed at room temperature and also reported on circular plasmids suggests that the more molecules are involved in the conduction process, the higher are the current values measured. At the same time, a characteristic steplike feature superimposed to an overall increasing background appears more pronounced. We interpret this behavior in terms of simultaneous coherent and incoherent transport processes, the former taking place inside the DNA molecule, the latter through the network of molecules. Following our previous analysis on circular molecules, a phenomenological model is developed, in which a tunneling current with an energy dependent transmission coefficient is superimposed to a hopping current. The model provides a semiquantitative evidence that the steplike feature represents the signature of charge transmission inside the molecule. Our results are consistent with many of the conductivity data present in the literature. © 2009 American Institute of Physics
Building future standard and Knowledge Management for Inventory Management in Logistics Europe Central
No full textCílem této diplomové práce je vytvořit standardy a Knowledge Management pro procesy týkající se řízení zásob v oddělení logistiky v centrální Evropě. Teoretická část přibližuje Lean Management a jeho principy se zaměřením na administrativní prostředí. Pojednává o důležitosti a výhodách standardů a Knowledge Management v Lean kontextu. Dále podává přehled o současných Lean aktivitách v dané spološnoti. Nakonec popisuje relevantní Lean nástroje použité k rozdělení a řízení jednotlivých projektových fází v praktické části této diplomové práce. Praktická část diplomové práce zobrazuje proces reálního vytvoření standardů a Knowledge Management v oddělení materiálového managementu. Čtenáři je poskytnut detailní náhled na projektové fáze doplněn názornými ukázkami. Na závěr práce je zhodnocen současný stav projektu a analyzována dosavadní zpětná vazba od zúčastněných osob. Autor rovněž poskytuje své rady a doporučení pro budoucí pokračování projektu ze strategické, taktické a operativní perspektivy.The aim of this master thesis is to build standards and Knowledge Management for the Inventory Management in the Materials Management department in the Logistics Europe Central region. The theoretical of this master thesis part provides a theoretical basis in Lean management with the focus on administrative environment. It further clarifies the importance and benefits of standards and Knowledge Management in the context of Lean and describes Lean frameworks used for building the project steps of the practical part of this master thesis. Furthermore, an overview about current Lean practices in the company is provided. The practical part of this master thesis portrays the establishment and development of standards and Knowledge management in the Materials Management department. In details, the project steps are discussed and illustrated where applicable. Status update of the project is provided including the feedback of relevant stakeholders. Lastly, author gives recommendations for the further continuation of the project for the department from strategic, tactical and operational perspective
Negative control of liver-specific gene expression: cloned human retinol-binding protein gene is repressed in HeLa cells.
No full textDefective mutant of sindbis virus with a smaller-molecular-weight form of the E1 glycoprotein
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