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Osmotic permeability characteristics and the effects of cryoprotectants are important determinants of recovery and function of spermatozoa after cryopreservation. The primary purpose of this study was to determine the osmotic permeability parameters of human spermatozoa in the presence of cryoprotectants. A series of experiments was done to: 1) validate the(More)
Use of a cryoprotective agent is indispensable to prevent injury to human spermatozoa during the cryopreservation process. However, addition of cryoprotective agents to spermatozoa before cooling and their removal after warming may create severe osmotic stress for the cells, resulting in injury. The objective of this study was to test the hypothesis that(More)
K562 is a human leukemic cell line used as model of hematopoietic differentiation. A variety of differentiation-inducing agents was used in this study, and the expression of surface membrane antigens associated with specific lineages of differentiation and changes in the cytochemistry of the induced cells were monitored. Sodium butyrate, hemin, retinoic(More)
Originally isolated from bone marrow, mesenchymal stromal cells (MSCs) have since been obtained from various fetal and post-natal tissues and are the focus of an increasing number of clinical trials. Because of their tremendous potential for cellular therapy, regenerative medicine and tissue engineering, it is desirable to cryopreserve and bank MSCs to(More)
Fundamental cryobiological characteristics of spermatozoa from threatened or endangered species must be determined for successful cryopreservation techniques to be established. In this study, spermatozoa from four diverse species, impala (Aepyceros melampus), wart hog (Phacochoerus aethiopicus), elephant (Loxodonta africana), and lion (Panthera leo), were(More)
OBJECTIVE Transplantation of osteochondral allograft tissue can treat large joint defects but is limited by tissue availability, surgical timing, and infectious disease transmission. Fresh allografts perform the best but requirements for infectious disease testing delay the procedure with subsequent decrease in cell viability and function. Hypothermic(More)
Cryobiological studies of tissues often require the simultaneous assessment of tissue structure and in situ cellular function. Localization of damage during cryopreservation occurs as a consequence of tissue structure and morphology and as a result of biophysical constraints imposed by diffusion and heat transfer. This study used five experimental model(More)
Preservation of cells and tissues at low temperatures requires the presence of effective cryoprotectants with low toxicity to which cells are relatively permeable. Two similar compounds, dimethyl sulfoxide (DMSO) and dimethyl sulfone (DMSO2), exhibit both features for cryoprotectants, yet DMSO is a very effective cryoprotectant while DMSO2 is ineffective.(More)
A hypothesis of the nature of intracellular ice formation is proposed in which the osmotically driven water efflux that occurs in cells during freezing (caused by the increased osmotic pressure of the extracellular solution in the presence of ice) is viewed as the agent responsible for producing a rupture of the plasma membrane, thus allowing extracellular(More)