[A two-step protocol for induction of rat adipose tissue-derived stem cells into neuron-like cells].

OBJECTIVE: To investigate the differentiation potential of rat adipose tissue-derived cells (ADSCs) into neuron-like cells in vitro using a two-step induction protocol. METHODS: ADSCs isolated from the epididymal fat pads in male SD rats by means of differential attachment were cultured in vitro and subjected to adipogenic induction. After flow cytometric identification of the cell surface antigens CD106, CD11b, CD45, CD49d, CD90 and CD29, the third-passage ADSCs were induced to transdifferentiate into neural stem cell (NSC)-like cells in DMEM/F12 medium containing 10 ng/ml basic fibroblast growth factor (bFGF), 20 ng/ml epidermal growth factor (EGF) and 2% B27. The resultant NSC-like cells were then induced to differentiate into neuron-like cells in the neurobasal medium containing 10 ng/ml brain-derived neurotrophic factor (BDNF), 10 ng/ml glial cell line-derived neurotrophic factor (GDNF) and 1 µmol/L retinoic acid (RA). Immunocytochemistry was employed to identify the expression of the cell surface markers nestin, MAP2 and NeuN. RESULTS: The isolated ADSCs were positive for CD90 and CD29, and oil red O staining of the induced adipose-like cells yielded positive results. The third-passage ADSCs induced for 7 days aggregated as floating cell spheres positive for NSC surface antigen nestin. Further induction in neurobasal medium for 4 h resulted in adhesion of the cell spheres and the formation of cell processes extending from some peripheral cells, suggesting a morphological resemblance to neurons. Most of the cells showed positivity for MAP2 and NeuN. CONCLUSION: ADSCs can be induced to differentiate into neuron-like cells in vitro under appropriate conditions.

[Correlation of snoring with attention deficit and hyperactivity-impulsivity in school age children from Changsha City].

OBJECTIVE: To investigate the prevalence of snoring in school age children from Changsha City, and study the correlation of snoring with attention deficit and hyperactivity-impulsivity. METHODS: A total of 1 736 children aged 6 to 12 years were randomly sampled from five districts in Changsha City. Their parents completed the questionnaires about children's sleep conditions and the Attention Deficit Hyperactivity Disorder Diagnostic Scale-Parent Version. RESULTS: The total incidence rate of frequent snoring was 5.7%. Boys had higher incidence of frequent snoring than girls (7.5% vs 3.8%; x2=18.782, p<0.01). The incidence of snoring in the 6-to 9-year-old group was higher than that of the 10-to 12-year-old group (x2=9.666, P<0.01). The incidence of daytime sleepiness in the snoring group was higher than that in the non-snoring group (31.5% vs 25.9%; x2=6.678, p<0.01). The incidences of larynx choking, sleep apnea, mouth breathing, hyperhidrosis, and awaking for unknown reasons or awaking by choke in the frequent snoring group were significantly higher than in the occasional snoring and the non-snoring groups (x2=37.035, 27.745, 51.341, 30.975, 45.972 respectively; all P<0.01). The incidences of attention deficit (31.3%) and hyperactivity-impulsivity (18.2%) in the frequent snoring group were the highest, followed by the occasional snoring (16.2% and 9.9% respectively) and the non-snoring groups (13.9% and 8.8% respectively). There were significant differences in the incidence of both attention deficit (x2=20.592, p<0.01) and hyperactivity-impulsivity (x2=9.067, p<0.05) between groups. CONCLUSIONS: There is a high incidence of snoring in school age children from Changsha City. Snoring is correlated to attention deficit and hyperactivity-impulsivity. It is essential to pay attention to the mental growth and behavioral problems in children with sleep snoring.

[Induced differentiation of rat adipose-derived stem cells into Schwann-like cells].

OBJECTIVE: To assess the differentiation potential of rat adipose-derived stem cells (ADSCs) into Schwann-like cells in vitro. METHODS: ADSCs isolated from adult SD rats were cultured in vitro and identified with the cell surface antigens CD44, CD49d and CD106 by immunocytochemistry. The ADSCs of the sixth to eighth passages were inoculated in polylysine-coated culture plate and cultured for 12 days in DMEM/F12 culture medium containing 10% fetal bovine serum, 5 ng/ml platelet-derived growth factor, 10 ng/ml basic fibroblast growth factor, 14 micromol/L Forskolin and 200 ng/ml Heregulin to induce their differentiation in vitro. Immunocytochemistry was performed to identify the expression of the cell surface markers nestin, glial fibrillary acidic protein (GFAP), S-100, and P75. RESULTS: The isolated and purified ADSCs were positive for CD44 and CD49d expressions but negative for CD106. After 12 days of culture in the conditional culture medium, most of the cells showed positive expressions of GFAP, S-100, and P75, the specific protein markers of Schwann cells. CONCLUSION: Adult rat ADSCs are confirmed to have potentials of neuroglial differentiation and capable of differentiating into Schwann-like cells in vitro.