[A comparative analysis of the efficacy of two vitamin D supplementation regimens in preterm infants: a prospective randomized controlled study].

Objective: To study the effect of different vitamin D supplementation regimens on the nutritional status of vitamin D on day 28 after birth in preterm infants with a gestational age of <34 weeks.

Methods: A total of 59 preterm infants with a gestational age of <34 weeks who were born from October 2018 to October 2019 were enrolled and divided into an observation group with 30 infants and a control group with 29 infants. The infants in the observation group received a single-dose intramuscular injection of vitamin D (10 000 IU/kg), while those in the control group received oral vitamin D drops (900 IU/d) for 25 days.

[Site-directed mutagenesis and protein expression of ABCA3 gene in A549 cells].

Objective: To study the protocol of construction of the mutation E292V and M723I of hABCA3 gene associated with neonatal respiratory distress syndrome, as well as their eukaryotic green fluorescent protein expression rectors, and to examine the expression of mutation proteins in human lung carcinoma epithelial cells (A549).

Methods: Site-directed mutagenesis method based on overlap extension PCR was used to introduce mutations in the two sites which were E292V and M723I in the ABCA3. The PCR fragments were subcloned to PEGFP-C2 vectors to construct the eukaryotic green fluorescent protein expression rectors.