First | Previous | Next | Last | | Index | Home Slide 22 of 63 In order to be used clinically, human embryonic stem cells must be differentiated prior to use in patients. Undifferentiated stem cells could produce tumors and multiply unchecked within a patient, causing more problems than providing appropriate therapy. It is uncertain if conditions can be defined such that all embryonic stem cells differentiate into the correct cell type prior to therapeutic use. Complications caused by undifferentiated cells might not be discovered until years after the first clinical trials are begun. This differentiation problem is acknowledged on the International Society for Stem Cell Research website:
Recently, three established stem cell lines were shown to exhibit abnormalities in One of the threadlike "packages" of genes and other DNA in the nucleus of a cell. Different kinds of organisms have different numbers of chromosomes. Humans have 23 pairs of chromosomes, 46 in all: 44 autosomes and two sex chromosomes. Each parent contributes one chromosome to each pair, so children get half of their chromosomes from their mothers and half from their fathers.chromosome number and structure.2, 3 Obviously, stem cell lines must be checked periodically to make sure the cells do not become abnormal during continued culture. The use of abnormal cells in treatment of patients could result in indeterminate complications. References
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Last Modified August 2, 2004