Kosair Childrens Hospital Research Institute
Kosair Childrens Hospital Research Institute
Cai J.,University of Louisville |
Cai J.,Kosair Childrens Hospital Research Institute |
Zhu Q.,University of Louisville |
Zheng K.,University of Louisville |
And 6 more authors.
GLIA | Year: 2010
Recent studies have suggested that Nkx6.2/Gtx and Nkx2.2 homeodomain transcription factors are involved in the regulation of oligodendrocyte maturation and/or myelination which occur predominantly in postnatal stages. However, their cellular specificity in postnatal central nervous system has not been characterized and their dynamic expressional relationship during oligodendrocyte lineage progression has not been determined. Here we report that both Nkx2.2 and Nkx6.2 are selectively expressed in Olig2+ cells of oligodendrocyte lineage in postnatal spinal cords. Although Nkx6.2 is specifically expressed in the APC+ mature oligodendrocytes, Nkx2.2 is initially expressed in differentiating oligodendrocyte precursor cells (OPCs) but quickly down-regulated as OPCs undergo terminal differentiation. Intriguingly, Nkx2.2 expression is up-regulated in mature myelinating oligodendrocytes at later stages. The co-expression of Nkx2.2 and Nkx6.2 transcription factors in myelinating oligodendrocytes suggests their functional interactions in the regulation of myelin sheath formation and/or maintenance. © 2009 Wiley-Liss, Inc.
Bhattacharjee R.,University of Louisville |
Alotaibi W.H.,University of Louisville |
Kheirandish-Gozal L.,University of Louisville |
Capdevila O.S.,University of Louisville |
And 2 more authors.
BMC Pediatrics | Year: 2010
Background: Endothelial dysfunction is a complication of both obesity and obstructive sleep apnea syndrome (OSAS), the latter being highly prevalent among obese children. It is unknown whether obesity causes endothelial dysfunction in children in the absence of OSAS. This study examines endothelial function in obese and non-obese children without OSAS.Methods: Pre-pubertal non-hypertensive children were recruited. Endothelial function was assessed in a morning fasted state, using a modified hyperemic test involving cuff-induced occlusion of the radial and ulnar arteries. The absence of OSAS was confirmed by overnight polysomnography. Anthropometry was also performed.Results: 55 obese children (mean age 8.6 ± 1.4 years, mean BMI z-score: 2.3 ± 0.3) were compared to 50 non-obese children (mean age 8.0 ± 1.6 years, mean BMI z-score 0.3 ± 0.9). Significant delays to peak capillary reperfusion after occlusion release occurred in obese compared to non-obese children (45.3 ± 21.9 sec vs. 31.5 ± 14.1 sec, p < 0.01), but no differences in the magnitude of hyperemia emerged. Time to peak reperfusion and percentage of body fat were positively correlated (r = 0.365, p < 0.01).Conclusions: Our findings confirm that endothelial dysfunction occurs early in life in obese children, even in the absence of OSAS. Thus, mechanisms underlying endothelial dysfunction in pediatric obesity are operational in the absence of sleep-disordered breathing. © 2010 Bhattacharjee et al; licensee BioMed Central Ltd.
Spruyt K.,Kosair Childrens Hospital Research Institute |
Capdevila O.S.,Kosair Childrens Hospital Research Institute |
Serpero L.D.,Kosair Childrens Hospital Research Institute |
Kheirandish-Gozal L.,Kosair Childrens Hospital Research Institute |
Gozal D.,Kosair Childrens Hospital Research Institute
Journal of Pediatrics | Year: 2010
Objective: To assess dietary and physical activity patterns and morning circulating blood levels of the orexigenic hormones ghrelin and visfatin in children with either obesity, obstructive sleep apnea (OSA), or both conditions. Study design: In this cross-sectional design, 5- to 9-year-old participants (n = 245) from the community were identified. After overnight polysomnography, caregivers filled out a food and physical activity questionnaire, and the child underwent a fasting blood draw for ghrelin and visfatin plasma levels. Results: Compared with control subjects, obese children with OSA ate 2.2-times more fast food, ate less healthy food such as fruits and vegetables, and were 4.2-times less frequently involved in organized sports. OSA was positively correlated with plasma ghrelin levels (R2, 0.73; P < .0001), but not visfatin levels, particularly when obesity was present. Conclusion: OSA and obesity in children may adversely impact dietary preferences and may be particularly detrimental to daily physical activity patterns. Furthermore, increased ghrelin levels support the presence of increased appetite and caloric intake in obese patients with OSA, which in turn may further promote the severity of the underlying conditions. © 2010 Mosby, Inc. All rights reserved.