ABSTRACT
Two important parameters for determination of deleterious effects of cellular processing on hematopoietic progenitor cells are cell viability and concentration. The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital evaluated the Beckman Coulter Vi-Cell automated instrument for the measurement of these two parameters. Using 33 thawed hematopoietic progenitor cell samples, automated Vi-Cell viability results were compared to those obtained using the standard trypan blue manual method. In addition, cell concentrations from these samples were compared with results from the Model Z2 Coulter Counter. Chinese Hamster Ovary cells were used for the evaluation of Vi-Cell linearity at the Beckman Coulter Cellular Analysis Development Center. Significant correlation was obtained when the two methods were compared for both cell concentration and percentage viability (P < .0001). The results of the linearity study indicated that the Vi-Cell is linear from approximately 5 x 10(4) to greater than 1 x 10(7) cells/mL. The Vi-Cell uses sample volumes as low as 0.5 mL; cell diameters may be 2 to 70 microns. The Vi-Cell automated instrument offers many significant advantages for cell analyses in today's busy laboratory environment.
Subject(s)
Cell Count/instrumentation , Cell Survival , Evaluation Studies as Topic , Hematopoietic Stem Cells , Animals , Autoanalysis/instrumentation , Autoanalysis/methods , COS Cells , Cell Count/methods , Cricetinae , Cryopreservation , Humans , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
Split-thickness grafts of skin of satisfactory quality were found to be more difficult to obtain from rabbits than from animals of other genera. An explanation for this was sought in the histology of the skins of the various experimental animals. Density of hair was judged to be the factor most critical for ease or difficulty in procuring satisfactory split-thickness grafts of skin, and a cluster of histologic characteristics of skin seemed to have meaning for taxonomic classification. Silver's dermatome was found to be the test instrument for taking grafts from all subjects.
Subject(s)
Skin Transplantation , Animals , Cats , Dogs , Guinea Pigs , Hair/anatomy & histology , Humans , Methods , Mice , Rabbits , Rats , Skin/anatomy & histology , Species Specificity , Swine , Transplantation, HomologousABSTRACT
Skin grafts placed over burn wounds were first reported to reduce bacterial growth levels about 20 years ago. Recently, three separate groups of investigators have studied effects of skin in vitro in order to better understand the mechanism of this in vivo phenomenon. Although significant bacterial inhibition was not found, the interaction of host tissue factors with the skin which is possible in vivo was not included in these experiments. Hence, the question of in vitro activity of skin was still not resolved. In this experiment human and pig skin, fresh and preserved, intact and homogenated, were all tested separately with and without active serum against four representative bacteria and one fungus, individually and in mixed cultures. No growth inhibition was observed under any circumstances on daily review for up to three-week periods. In light of conflicting reports related to antibacterial effects of skin grafts used clinically, it now seems important to definitively clarify whether skin really possesses antibacterial properties in vivo.
