[Impacts of biological and family factors on lexical and intellectual development in Mandarin-speaking children].

OBJECTIVE: To investigate the impacts of biological factors (age and sex) and family factors (socioeconomic status and parenting style) on the early lexical and intellectual development of children in a longitudinal tracking study. METHODS: A total of 38 Mandarin-speaking children aged from 18 to 24 months were surveyed using the Putonghua Chinese Communicative Development Inventory (PCDI), the Ages and Stages Questionnaire (ASQ), and a self-designed Questionnaire for Parents. All of the subjects were retested using PCDI and ASQ after 6 months. RESULTS: Biological factors accounted for 65% of the variance in lexical development, 10% of which was attributed to gender, in the first survey. After six months, the contribution of age decreased to 26% and gender had no significant impact. Lexical development could positively predict the intellectual development of children. When age and gender were controlled, it accounted for 22% of the variance in intellectual development. Family socioeconomic factors had no significant impacts on lexical and intellectual development. Children's recognition of people and objects around them with guidance of parents in parenting styles could positively predict the intellectual development of children six months later, which accounted for 10% of the variance. CONCLUSIONS: Biological factors play an important role in the early lexical development of children. However, the influence decreases with the increase of age (months). Biological factors, lexical development, and parenting style have a combined influence on children's intellectual development.

Enhancement of transfection efficiency with NLS and SPB-NLS.

Low positive cell screening efficiency severely hinders the development of transgenic animals. The major rate-limiting step of positive cell screening is DNA entering the nucleus, particularly for large DNA molecules. To enhance the transport of large DNA molecules into the nucleus, particularly for the production of transgenic animals, nuclear localization sequence (NLS) peptides and the peptide derivative succinimidyl-[4-(psoralen-8-yloxy)]-butyrate (SPB)-NLS were synthesized to mediate transfection in vitro. To investigate the function of NLS and SPB-NLS in vitro, the expression levels of growth hormone (GH) mRNA and green fluorescent protein (GFP) protein were analyzed following transfection mediated by NLS and SPB-NLS. The results demonstrated that the expression of GH mRNA was significantly higher in the NLS (increased by 69%) and SPB-NLS (330%) groups than that in the liposome/pGN group. Similarly, GFP expression was found to be higher in the SPB-NLS group than that in the liposome group, while the expression in the NLS group was lower than that in the liposome group. Further analysis demonstrated that SPB-NLS enhanced the expression of insulin-like growth factor 1 in hard-to-transfect goat mammary epithelia cells. The results of the microscopy analysis revealed that transfected DNA entered the nucleus via the nuclear pores, facilitated by NLS. Analysis of the cell cycle demonstrated that the cytotoxic effects of NLS and SPB-NLS were low. In conclusion, the results of the present study demonstrate that SPB-NLS acts as a transfection-enhancing agent and may be used both to enhance nuclear delivery and for the development of genetically modified animals.

Enhancement of gene transfer efficiency in the Bcap-37 cell line by dimethyl sulphoxide and menthol.

Simple and efficient gene transfer into the nucleus would facilitate non-viral gene delivery. One promising method of non-viral gene delivery is to apply penetration enhancers. Chemicals, such as dimethyl sulfoxide (DMSO) and menthol, may have promise as non-toxic vehicles in improving gene transfer efficiency. In this study, the cytotoxic effects of DMSO and menthol were evaluated using MTT assays. Gene delivery efficiency in a human breast cancer cell line (Bcap-37) was investigated by quantitative PCR, fluorescence microscopy and flow cytometry. Non-toxic concentrations of DMSO (2%) and menthol (12.5 µM) enhanced the efficiency of liposome-mediated gene delivery in Bcap-37 cells. Quantitative PCR results showed that growth hormone (GH) mRNA expression in the post-menthol and pre-DMSO treatment groups was 10-fold higher compared to that in the liposome group, while in the pre-menthol and post-DMSO treatment groups, a 30-fold increase in GH mRNA expression was observed. Both DMSO and menthol treatments increased green fluorescent protein (GFP) expression efficiency as shown by fluorescence microscopy experiments. Compared to the liposome group, the number of positive cells in the pre-menthol and post-DMSO treatment groups was significantly increased by 15%. Furthermore, cell cycle analysis demonstrated that there were significant differences among the DMSO-treated group, the menthol-treated group and the normal group, which implied different effects of DMSO and menthol treatments. In conclusion, both non-toxic and harmless DMSO (2%) and menthol (12.5 µM) treatments improve gene transfer efficiency, while post-DMSO treatment may be the most effective protocol in increasing transgene expression efficiency.

[Factors influencing the language development of preterm infants].

Along with the development of pediatric emergency technology, more preterm infants with extremely small gestational age and birth weight can survive, yet the long-term follow-up of their neuropsychological development needs to be focused. Language development of preterm infants is an important component of their intellectual development, which reflects the development of their nervous system. Studies about how language develops in preterm infants and what factors are relevant yield inconsistent results. This paper describes the factors influencing the language development of preterm infants, such as gestational age, birth weight and gender. It provides suggestions as to future research and clinical intervention for the language development of preterm infants.