Placenta serves as an important organ, which determines the establishment of pregnancy and intrauterine fetal growth, as well as the complex maternal-fetal crosstalk. Different subtypes of trophoblast cells mediate the diverse functions of the placenta. During placental development, the trophectoderm-derived trophoblast stem cells differentiate into all subtypes of trophoblasts and thus maintaining the structure and function of the placenta. Histone modifications can regulate chromatin structure and gene transcription, which is involved in the establishment, maintenance and differentiation of trophoblast lineage. In this review, we systemically overview the indispensable roles of histone methylation and acetylation in trophoblast differentiation.

Placenta serves as an important organ, which determines the establishment of pregnancy and intrauterine fetal growth, as well as the complex maternal-fetal crosstalk. Different subtypes of trophoblast cells mediate the diverse functions of the placenta. During placental development, the trophectoderm-derived trophoblast stem cells differentiate into all subtypes of trophoblasts and thus maintaining the structure and function of the placenta. Histone modifications can regulate chromatin structure and gene transcription, which is involved in the establishment, maintenance and differentiation of trophoblast lineage. In this review, we systemically overview the indispensable roles of histone methylation and acetylation in trophoblast differentiation.

Objective To evaluate the diagnosis and differentiation of solitary pulmonary nodule (SPN) using dynamic spiral CT scan of thin collimation.Methods The thin collimation no-enhanced CT scan and contrast enhanced scan in 30 seconds,1 minute,1 minutes,2 minutes,5 minutes,10 minutes,and 15 minutes after administration of media 100 ml were performed in 38 cases. Results The mean enhanced CT numbers of lung cancer and inflammatory pseudotumor were much higher than that of tuberculosis(TB) and hamartoma and statistically significant in different time of enhancement;20 HU was the threshold for a positive test,the sensitivity was 100% and the specificity was 96%.In time-attenuation curve analysis,lung cancer reached peak enhancement about 2 minutes,inflammatory pseudotumor in 5 minutes and keep longer enhanced time than that of lung cancer.No marked enhancement in SPN of TB and harmatoma,but ring-shaped enhancement can be seen in some of TB.More valuable imaging signs were found with thin collimation scan and more accurate to measure the CT numbers than traditional scan.Conclusion Dynamic spiral CT scan of thin collimation is a very valuable method for diagnosis and differentiation of SPN.