细胞功能测定

Pluripotent embryonic stem (ES) cells are an important model system to examine gene expression and lineage segregation during differentiation. One powerful approach to target and inhibit gene expression, RNAi, has been applied to ES cells with the goal of teasing out the cascades of gene exp ...

A variety of mutations, including those affecting laminin expression and basement mem-brane, cause early embryonic lethality in the peri-implantation period. However, low cell numbers and inaccessibility of these small embryos make it difficult to study the molecular mechanisms ...

Embryonic stem (ES) cell lines are important for use in developmental biology studies, and because these cells are totipotent, they may provide a much-needed source of differentiated cells for certain therapeutic applications. The phenotype of the ES cell in culture is often assessed by (s ...

The derivation of specialized differentiated cells from embryonic stem (ES) cells is now a major focus for future therapies involving cell and organ replacement in humans. To obtain populations of differentiated cells for transplantation into the human body, highly optimized proto ...

The major limitations in gene transduction to embryonic stem (ES) cells are (1) low efficiency of gene delivery and (2) suppression of gene expression after integration into the host genome. A human immunodeficiency virus type 1 (HIV-1)-based lentiviral vector has been demonstrated to be an e ...

Embryonic stem (ES) cells are pluripotent cells derived from the epiblast of preimplantation embryos. These cells are emerging as a key model system for elucidating mechanisms involved in development and disease as well as having a unique potential as a source of unlimited somatic cells for t ...

The ability to stably introduce genetic material into primate embryonic stem (ES) cells could allow broader application. In this chapter, we describe a method of gene transfer into simian (cynomolgus macaque) ES cells using a simian immunodeficiency virus-based lentivirus vector. Wh ...

Monkey embryonic stem (ES) cells are a useful tool for studying early human development and evaluating the efficacy of stem cell therapy. Monkey ES cells show closer similarity to human ES cells than their mouse counterparts regarding morphology, cell surface markers, and the maintenance of ...

Embryonic stem (ES) cells, and the inner cell mass from which they are derived, are hypersensitive to DNA damage and appear to have specific cellular defense systems for DNA repair and the elimination of damaged cells. These mechanisms differ from somatic cells and are vital to minimize developm ...

Mutation in embryonic stem (ES) cells can potentially compromise multiple cell lineages and affect the well-being of subsequent generations. Thus, ES cells require sensitive mechanisms to maintain genomic integrity. One mechanism involves suppression of mutation. A complemen ...

The process of bringing a new pharmacologically active drug to market is laborious, time consuming, and costly. From drug discovery to safety assessment, new methods are constantly sought to develop faster and more efficient procedures to eliminate drugs from further investigation be ...

Adipocytes and osteoblasts are derived from a common precursor cell. It has been proposed that the bone loss commonly seen during aging or in the pathology of osteoporosis might be partly caused by a deregulation of the normal balance between osteoblast and adipocyte differentiation. In vit ...

An important topic in membrane biochemistry is the determination of the sidedness of the components comprising a biological membrane. Neither phospholipids nor membrane proteins are distributed symmetrically over inner and outer aspects of cellular membranes, and knowledge of ...

Phospholipid-transfer proteins (PL-TP) have been isolated from a number of tissues, including heart, liver, and brain (1). These proteins catalyze the one-for-one exchange in vitro of phospholipid molecules between membranes, lipoproteins, or liposomes. The functions of PL-TP in vivo ...

The synthesis, characterization, and use of fluorescently labeled lipid probes to follow transport in living cells at a microscopic level have greatly expanded our knowledge of intracellular lipid trafficking. Although lipids containing a number of covalently attached fluoro ...

The first measurement of the transmembrane diffusion of phospholipids in membranes was carried out by Kornberg and McConnell in 1971 (1). These authors sonicated an aqueous suspension of egg lecithin mixed with a small percentage of a spin-labeled phosphatidylcholine. The spin-labe ...

This chapter details the procedural and conceptual issues that underpin the localization of high-affinity amino acid transporters by immunocytochemistry, with particular reference to the mammalian nervous system. Defining a role for transporters in any individual tissue of ...

Transmembrane ion channels, or, more broadly, membrane transporters, are the subject of electrophysiology that leads us to the understanding of nearly every event of biological activities. Since the introduction of patch clamp concepts and techniques (1,2), transmembrane ion chan ...

One way to characterize structure and function in transporters is chemical. The analysis specifies the three-dimensional structure of the transporter and changes in structure that occur during the transport cycle. It can ignore intermediate steps in the cycle by showing only reactan ...

During oogenesis, Xenopus oocytes accumulate large amounts of storage proteins that—after fertilization—provide the developing embryo with building blocks and energy metabolites. The size of the fully developed oocyte (diameter, 1.2 mm) is largely governed by the stored amounts ...