Available evidence strongly suggests that early weaning and extubation are desirable, but our ability to predict the point at which can be accomplished safely in extremely preterm remains limited.Extubation failure remains frequent and may carry significant short and long-term consequences.Improved tools for predicting successful extubation in this population are currently being explored with the hope of reducing extubation failure and the attendant risks of reintubation.This review summarized and analyzed the related problems in the peri-extubation period of extremely preterm, in order to provide reference for successful extubation and weaning of ventilatory as soon as possible.

Purpose To investigate the clinicopathological features of adolescent mixed epithelial and stromal tumor of the kidney ( MESTK) and improve recognization of this rare disease. Methods Clinicopathological and immunohistochemical characteristics of MESTK occured in 17-year-old girl were studied. Reviewed the related literatures, clinical and pathological characteristics of adoles-cent MESTK were analysed comprehensively. Results Congenital perineal spill was the main clinical manifestations. Microscopically, the tumor showed nodules and was composed of a mixture of epithelial and stromal elements. Glands were lined with columnar or cilia-ted columnar cells. Stromal cells surrounding glands seemed like ovaries and away from glands seemed like the differentiation of smooth muscle. Immunohistochemical staining revealed that the epithelial cells were positive for CK7 and vimentin. Stromal cells expressed desmin, smooth muscle actin ( SMA) , ER and PR. It was noteworthy that stromal cells away from glands expressed desmin. Conclu-sions As a kind of rare benign neoplasm of kidney, MESTK often occurs in perimenopausal women. But MESTK can also occur in ad-olescence, and has nothing to do with the use of hormone. Therefore, the renal tumor occurred in teenagers with biphasic differentiation should be differentiated from MESTK.