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Background: A simple and reproducible model of hepatectomy provides an essential basis for the study of liver regeneration. However, current rodent models of hepatectomy involve lobectomy, which cannot simulate clinical liver resection with surgical margins. The main purpose of this study was to evaluate a novel murine modeling technique for hepatectomy using a gutta cutter., Methods: Seventy-five C57BL/6 mice were randomly divided into 3 groups (n = 25 mice per group). Group 1 (control) underwent single ligature of the left lobe. Group 2 underwent left lobe local (5-mm diameter) hepatectomy by gutta cutter. Group 3 underwent partial left lobe resection (1.5 cm) by gutta cutter. Postoperative complications were analyzed. Serum aspartate transaminase, alanine aminotransferase, alkaline phosphatase, urea nitrogen, interleukin 6, and tumor necrosis factor-α were detected using an automatic biochemical analyzer. Hematoxylin-eosin and immunohistochemical staining was used to examine pathology, proliferating cell nuclear antigen, caspase-3, CD34, signal transducer and activator of transcription 3 (STAT-3), and phosphorylated STAT-3 (p-STAT-3)., Results: Major postoperative complications, hepatic enzymes, kidney function, interleukin 6, and tumor necrosis factor-α were similar among the groups (all P > .05). Histology showed little necrosis and a clear surgical boundary in groups 2 and 3. Groups 1 and 3 had higher positive cell levels (proliferating cell nuclear antigen, CD34, p-STAT-3) than group 2 (P < .05). There were no significant differences in caspase-3 and STAT-3 positive cells., Conclusions: Hepatectomy in mice using a gutta cutter to better mimic human liver resection shows potential as an alternative and safe animal model. This model may be useful in investigating methods of promoting liver regeneration., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

The liver is an organ with regenerative capacity and is essential for maintaining the body homeostasis. Under pathological conditions, such as chronic hepatitis, liver cirrhosis and so on, the impairment of liver regeneration can lead to insufficient liver function or even liver failure. Therefore, promoting liver regeneration can improve the patient's prognosis. Prostaglandin E2 is a hormone-like messenger with physiological activity that can promote tissue regeneration. This article reviews the metabolism and transport pathways of prostaglandin E2 and its mechanism of action in liver tissue regeneration, and proposes that prostaglandin E2 is an important cytokine involved in the liver regeneration process, and has potential clinical application prospects for the treatment of liver injury.

In two growing seasons of wheat (2015-2017), we conducted a field trial with Taishan 28 in Tai'an Academy of Agricultural Science Feicheng experimental base, Tai'an City, Shandong Province. There were four irrigation levels of 150 (A 1 ), 300 (A 2 ), 450 (A 3 ), and 600 (A 4 ) m 3 ·hm -2 , and four nitrogen application levels of 90 (B 1 ), 135 (B 2 ), 180 (B 3 ), and 225 (B 4 ) kg·hm -2 . We examined the effects of the combination effects of irrigation and nitrogen on dry matter accumulation and transport, nitrogen accumulation and transport, water consumption and utilization, photosynthetic characteristics, wheat grain yield and yield components of wheat. The results showed that dry matter accumulation, nitrogen accumulation, vegetative organs production, storage and the transportation volume to grains of the dry matter and nitrogen, and dry matter and nitrogen accumulation of grain in the mature stage of wheat all reached the maximum in A 3 B 3 treatment, which were significantly different from other treatments. Under all the nitrogen treatments, soil water consumption in the 60-200 cm soil layer was A 3 &gt;A 4 &gt;A 2 &gt;A 1 . Water use efficiency and nitrogen use efficiency in A 3 B 3 treatment were higher than that under A 3 B 4 , A 4 B 3 and A 4 B 4 . The net photosynthetic rate, stomatal conductance and transpiration rate of flag leaves from 7 to 28 days after flowe-ring were all significantly higher in A 3 B 3 treatment, which was conducive to the photosynthetic synthesis of carbohydrates in wheat. The interaction effect of water and nitrogen addition significantly affected grain yield and yield components. Wheat yield was the highest in A 3 B 3 treatment which reached at 9400 kg·hm -2 . In conclusion, the treatment with irrigation of 450 m 3 ·hm -2 and nitrogen of 180 kg·hm -2 could significantly improve dry matter and nitrogen accumulation, and promote transportation volume of the dry matter and nitrogen to grain. Compared with the high water and nitrogen treatment, it could effectively increase water use efficiency and nitrogen use efficiency, enhance photosynthetic capacity of flag leaf, produce more carbohydrate, and increase grain yield.