细胞功能测定

Cell-cell electrofusion (CCE) is a process that involves forcing cells into close juxtaposition and then inducing fusion by delivering electric pulses to the cells. CCE has proven to have many practical applications. It has been used for monoclonal antibody (Mab) production (4,5), hybrid ...

Recent studies reported the so-called “electroinsertion” of proteins having a membrane-spanning sequence into mouse red blood cell or Chinese hamster ovary cell membrane by exposing the cell suspension to electrical field pulses (1–6). The viability of the pulsed cells is not affected. ...

The discovery that one drug transporter, P-glycoprotein, decreases intracellular concentrations of many anticancer drugs explains how drug resistance could simultaneously develop to structurally unrelated compounds (1). These discoveries have focused attention on the ...

Drug resistance is a subject that covers two areas. In one case it refers to the ability of microbes to defeat antibiotics. In a different setting it refers to the ability of cancer cells to resist chemotherapy. In the first case, the drug resistance is evaluated on the basis of the percentage of viable cells a ...

Inhaled particles can cause a spectrum of responses ranging from simple clearance to pathologic reactions, including acute injury and chronic fibrosis. In vivo and in vitro studies of particulate interaction with lung cells has greatly advanced our understanding of the mechanisms of p ...

Cell plasma membranes act as highly impermeable barriers for the exchange of molecules between cells and external medium. Transfer of compounds can only take place via the existence of specific transport systems that allow a limited number of molecules to cross membranes. Alteration in me ...

The first evidence of clonal growth and differentiation of hematopoietic cells was obtained by Bradley and Metcalf in 1966 (1) by using an agar semi solid culture system. These progenitor cells, initially called “Colony Forming Units in Culture” (CFU-C) developed into colonies after sever ...

Nearly all hematopoietic cells in mammals derive from precursors that undergo much or all of their development in the bone marrow. In vitro models for many lineages are available and represent modifications of the original bone marrow culture system designed by Dexter and Lajtha (1). In this ch ...

Eukaryotic microalgae and prokaryotic cyanobacteria (blue-green algae) have traditionally been maintained by serial subculture, with the frequency of transfer being largely determined by the growth characteristics of the strain. This technique has the dual disadvantages of ...

Chloroplast thylakoids are the site of photosynthetic light reactions, electron transport, adenosine triphosphate (ATP) synthesis and nicotinamide adenine dinucleotide phosphate (NADP) reduction in plant cells. Isolated thylakoids are therefore the necessary prere ...

Free-living amoebae (FLA) are unicellular, eukaryotic protozoa found in virtually all soil and aquatic environments (1). All FLA are characterized by a feeding and replicating trophozoite form that, in most genera, can produce a resistant cyst stage in response to adverse conditions (1). F ...

Many aspects of mycology today necessitate living cultures. Traditional taxonomy is being supplemented by molecular biological techniques often requiring growing organisms. The need to keep particular strains for confirmation of results, further studies, and as references is ...

Increased interest in biotechnology along with the requirement for strains associated with patent applications to be deposited in a reconized collection, under the terms of the Budapest Treaty (1977), has increased the demand for the maintenance of microorganisms in designated cul ...

Viruses are noncellular forms of life and are much smaller and less biochemically complex than the simplest unicellular organisms. They consist of either RNA or DNA as a single molecule, or in some cases as a segmented genome, enclosed by one or more proteins. These proteins protect the nucleic acid f ...

The red blood cell (RBC), or erythrocyte, is a flexible biconcave disc 8 �m in diameter. Its main function is to carry oxygen from the lungs to the tissues of the body and to perform this it contains a pigment, hemoglobin. During its 120-d lifespan, it travels about 300 miles around the arteriovenous circulat ...

Spermatozoa were the first mammalian cells to be successfully cryopreserved (1), and the techniques developed by Sherman (2) enabled centers to begin to establish sperm banks for men at risk of losing their fertility as a result of clinical treatments for illness. Banks of cryopreserved donor ...

In 1972, Whittingham et al. (1) reported the first successful deepfreezing of mouse embryos. The method was efficient and reproducible, and it has been widely used since. This method includes a slow cooling process (this lasts a few hours after ice seeding). Recent attempts to improve the method have ...

The benefits of banking mammalian embryos for long-term storage have long been recognized (1). Cryopreservation of gametes prevents genetic drift, offering a viable alternative to maintaining active breeding colonies while safeguarding the genetic integrity of scientifica ...

Nature dictates that biological material will decay and die. The structure and function of organisms will change and be lost with time, as surely in laboratory cultures as in the biologists who study and manipulate them. Attempts to stop the biological clock have been conjured by minds ancient and ...

Although the first observations concerning low temperature preservation of spermatozoa date back to 1776 (when Spallanzani noted that spermatozoa, cooled in snow, became inactive but were revived on warming), successful cryopreservation protocols truly date from only the 1940s ...