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Diabetes is a disorder characterized by loss of β cell mass and/or β cell function, leading to deficiency of insulin relative to metabolic need. To determine whether stem cell-derived β [...]

The exchange of the oocyte's genome with the genome of a somatic cell, followed by the derivation of pluripotent stem cells, could enable the generation of specific cells affected in degenerative human diseases. Such cells, carrying the patient's genome, might be useful for cell replacement. Here we report that the development of human oocytes after genome exchange arrests at late cleavage stages in association with transcriptional abnormalities. In contrast, if the oocyte genome is not removed and the somatic cell genome is merely added, the resultant triploid cells develop to the blastocyst stage. Stem cell lines derived from these blastocysts differentiate into cell types of all three germ layers, and a pluripotent gene expression program is established on the genome derived from the somatic cell. This result demonstrates the feasibility of reprogramming human cells using oocytes and identifies removal of the oocyte genome as the primary cause of developmental failure after genome exchange., The generation of animals by transfer of the genome from an adult cell into an unfertilized oocyte (1), and the isolation of pluripotent stem cells from human blastocysts (2), raised [...]

Author(s): Mitsutoshi Yamada [1, 6]; Bjarki Johannesson [1, 6]; Ido Sagi [2]; Lisa Cole Burnett [3]; Daniel H. Kort [4, 5]; Robert W. Prosser [4, 5]; Daniel Paull [1]; Michael [...]

The corresponding authors were made aware of karyotype abnormalities through a routine quality control test of pluripotent stem cells used in the studies reported in this paper. After extensive internal [...]

Background. Ureaplasma urealyticum and its association with chronic lung disease (CLD) of prematurity has remained a controversial topic. To readdress this question, we performed a longitudinal study using culture and polymerase chain reaction to detect U urealyticum in the respiratory tract of very low birthweight infants throughout their neonatal intensive care unit hospitalizations. Methods. We screened 125 infants weighing Results. Forty infants (32%) had 1 or more positive specimens by culture or polymerase chain reaction. We identified 3 patterns of U urealyticum colonization: persistently positive (n = 18), early transient (n = 14), and late acquisition (n = 8). We compared the rates of CLD in each of the 3 colonized groups with the rate of CLD in the noncolonized group. We found a significantly higher rate of CLD at 28 days of age (odds ratio: 8.7; 95% confidence interval: 3.3, 23) and at 36 weeks' postconception (odds ratio: 38.5, 95% confidence interval: 4.0, 374) only for infants with persistently positive colonization. Conclusions. This study demonstrates that the risk of developing CLD varies with the pattern of U urealyticum colonization. Only the persistently positive colonization pattern, which accounted for 45% of the U urealyticum-positive infants, was associated with a significantly increased risk of development of CLD. Pediatrics 2002; 110(4). URL: http://www.pediatrics.org/cgi/content/full/ 110/4/e45; bronchopulmonary dysplasia, chronic lung disease, premature infant, polymerase chain reaction, Ureaplasma urealyticum, very low birth weight infant.