Robertsonian translocations are the most common chromosomal rearrangements in humans. The vast majority of the ten possible nonhomologous types of Robertsonian translocations ascertained are rob(13q14q) and rob(14q21q). Recombination between homologous sequences on nonhomologous chromosomes has been proposed as a mechanism leading to the preferential formation of rob(13q14q) and rob(14q21q). However, little evidence exists to indicate whether the remaining less common Robertsonian translocations form through a similar mechanism. To better elucidate the mechanisms involved in Robertsonian translocation formation, we have used fluorescence in situ hybridization to localize the breakpoints in 56 nonhomologous Robertsonian translocations. This study revealed highly variable locations of breakpoints in seven types of the less common Robertsonians, while nearly all rob(13q14q) and rob(14q21q) analyzed displayed breakpoints in the same locations. Therefore, this study provides direct evidence that rob(13q14q) and rob(14q21q) form through a specific mechanism, possibly involving homologous recombination, which is distinct from the mechanism(s) that contributes to the formation of the remaining types of Robertsonian translocations.

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BackgroundThe purpose of the study was to evaluate the effects of maternal pre-pregnancy body mass index (BMI) and gestational weight gain on perinatal outcomes in a population of Korean women.MethodsWe retrospectively reviewed the medical records of 2,454 women who had received antenatal care at Seoul St. Mary's Hospital from January 2007 to December 2009. We used World Health Organization definitions for Asian populations of underweight (BMI < 18.5), normal (BMI equal or higher 18.5 and < 23), overweight (BMI equal or higher 23 and < 25), and obese (BMI equal or higher 25). We analyzed perinatal outcomes according to the pre-pregnancy BMI and weight gain during pregnancy, and calculated the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) from multiple logistic regression models by considering maternal age, parity, number of fetuses, length of gestation, and medical history.ResultsAmong obese women, the adjusted ORs for gestational diabetes, hypertensive disorder, and incompetent internal os of cervix were 4.46, 2.53, and 3.70 (95% CI = 2.63-7.59, 1.26-5.07, and 1.50-9.12), respectively, and the adjusted ORs for neonatal complications such as macrosomia and low Apgar score were 2.08 and 1.98 (95% CI = 1.34-3.22 and 1.19-3.29), respectively, compared with normal weight women. However, there was no positive linear association between gestational weight gain and obstetric outcomes. In normal weight women, maternal and neonatal complications were significantly increased with inadequate weight gain during pregnancy (p < 0.0001 and = 0.0180, respectively), and we observed similar results in underweight women (p = 0.0136 and 0.0004, respectively).ConclusionsThis study shows that pre-pregnancy overweight and obesity are more closely related to the adverse obstetric outcomes than excess weight gain during pregnancy. In addition, inadequate weight gain during pregnancy can result in significant complications.

Human perinatal tissue is an abundant source of mesenchymal stromal cells(MSCs) and lacks the ethical concerns. Perinatal MSCs can be obtained from various tissues as like amnion, chorion, and umbilical cord. Still, little is known of the distinct nature of each MSC type. In this study, we successfully isolated and cultured MSCs from amnion(AMSCs), chorion(CMSCs), and umbilical cord(UC-MSCs). Proliferation potential was different among them, that AMSCs revealed the lowest proliferation rate due to increased Annexin V and senescence-associated β-galactosidase positive cells. We demonstrated distinct characteristic gene expression according to the source of the original tissue using microarray. In particular, genes associated with apoptosis and senescence including CDKN2A were up-regulated in AMSCs. In CMSCs, genes associated with heart morphogenesis and blood circulation including HTR2B were up-regulated. Genes associated with neurological system processes including NPY were up-regulated in UC-MSCs. Quantitative RT-PCR confirmed the gene expression data. And in vitro differentiation of MSCs demonstrated that CMSCs and UC-MSCs had a more pronounced ability to differentiate into cardiomyocyte and neural cells, respectively. This study firstly demonstrated the innate tissue-specific differentiation potency of perinatal MSCs which can be helpful in choosing more adequate cell sources for better outcome in a specific disease.