细胞功能测定

Analysis of promoter regulation is a powerful strategy for the study of regulatory interactions between genes that play a role in embryonic development. It allows investigation of the molecular mechanisms that underlay temporal and spatial expression of a specific gene. In addition, o ...

Zebrafish (Danio rerio) embryos have gained considerable popularity in recent years because they offer several advantages for developmental studies. The embryos are easy to manipulate, develop quite rapidly, and many genetic mutations are now becoming available. Classical cell ...

Expression of genes by introduction of DNA into developing embryos can be used to analyze promoter elements that are developmentally regulated or to ectopically express proteins to test their function during development. Because of its large size and resilience to manipulation, the Xe ...

Microinjection remains the most popular and effective of the methods to introduce DNA, RNA, and proteins into fertilized zebrafish eggs. The method is simple and reliable. A microinjection pipet is filled with the DNA or RNA solution and attached to an apparatus that forces the solution out of the p ...

The ease of obtaining large numbers of Xenopus laevis eggs and oocytes together with their size and robust nature have made them a popular choice when microinjection of macromolecules into a cell is required for protein expression and modification studies, protein function analysis, RNA p ...

Over the last 10 years, the animal cap of the Xenopus laevis embryo has proved to be a versatile test tissue for a variety of molecules involved not only in animal development but also vertebrate cell regulation in general. These molecules include growth factors (1–3), cell surface receptors (4–6), si ...

The authors have reported several comb-type copolymers, consisting of a polycation backbone such as poly-L-lysine (PLL) and hydrophilic side chains of polysaccharides, for controling the assembling structure of DNA-copolymer complexes (1–3). The DNA-copolymer system consis ...

There is an urgent requirement in the field of gene therapy for gene transfer vectors that are both safe to use and able to efficiently deliver therapeutic genes to target cells in vivo. Viral vectors, such as retrovirus, adenovirus, and herpes simplex virus, are efficient in transducing a broad ran ...

In recent years, interest in in vitro DNA condensation has been revived by efforts to develop vectors for nonviral gene therapy (1,2). One of the critical elements for successful and versatile delivery of specific genes into targeted cells is that DNA vectors of several kilobase pairs must be comp ...

Studies of the human genome have prompted the development of several cloning systems that can manipulate large fragments of human DNA as functional units. The discoveries in yeast of the sequences for replication (autonomously replicating sequence ), centromeres, and telomeres have ...

In vivo delivery of a cytokine gene to treat a tumor has usually involved either injection of ex vivo transfected cells around the tumor site or direct intratumoral injection of a virus or plasmid DNA (pDNA) vector encoding the cytokine gene (1,2). In this manner, transfected cells in or around the tumor ...

There are several strategies by which one may deliver a plasmid DNA (pDNA) encoding a therapeutic gene to a tumor. One may transfect cells ex vivo, single cell clone, expand the clone in vitro, and reinject the cells at the tumor site. This is a labor-intensive process and is especially impractical for hum ...

This chapter presents a qualitative description of the freeze-drying process as it pertains to the development of stable, dry polycation-DNA complex formulations. It is not intended to be a comprehensive treatise on freeze-drying. Readers are referred to a series of excellent papers by Pi ...

A powerful, yet often underutilized tool available to probe the structure of macromolecules is absorption spectroscopy. The first of the various spectroscopic techniques to be widely developed, data from absorption spectroscopy is commonly viewed as low in overall information co ...

For many decades, infrared (IR) spectroscopy has been used to characterize the structure of molecules. In IR spectroscopy, absorption of light, corresponding to vibrational and rotational transitions of a molecule, is measured. For a transition to be IR-active, a change in the dipole moment ...

Within the past 10 years, major advances in the design and development of differential scanning calorimeters (DSC) (1) and isothermal titration calorimeters (ITC) (2) have resulted in an unparalleled level of sensitivity, stability, and reproducibility in calorimetric measurem ...

Until now there is no renal gene therapy available for clinical use, however, gene therapy for several experimental renal diseases has been tested with promising results. The kidney is a well-differentiated organ with a variety of specialized compartments, i.e., vascular, glomerular, tu ...

The colloidal properties of delivery systems currently being developed for nonviral gene therapy are extremely important. The physical stability of these systems on the shelf, as well as in the biological milieu, is mostly based on their size and interfacial properties. The size and surface ...

Development of nonviral gene transfer techniques has progressed, particularly the use of several kinds of cationic lipids and cationic polymers such as polylysine derivatives, polyethyleneimines, polyamidoamine dendrimers, and so on, which electrostatically form a compl ...

Research and development related to nonviral gene carriers comprising chemically synthesized molecules has increased enormously during the past decade. Polycationic polymers and cationic lipids have constituted the main themes of the studies. Various polymers from synthe ...