Effect of Different Dietary Iron Contents on Liver Transcriptome Characteristics in Wujin Pigs.

Iron is an important trace element that affects the growth and development of animals and regulates oxygen transport, hematopoiesis, and hypoxia adaptations. Wujin pig has unique hypoxic adaptability and iron homeostasis; however, the specific regulatory mechanisms have rarely been reported. This study randomly divided 18 healthy Wujin piglets into three groups: the control group, supplemented with 100 mg/kg iron (as iron glycinate); the low-iron group, no iron supplementation; and the high-iron group, supplemented with 200 mg/kg iron (as iron glycinate). The pre-feeding period was 5 days, and the formal period was 30 days. Serum was collected from empty stomachs before slaughter and at slaughter to detect changes in the serum iron metabolism parameters. Gene expression in the liver was analyzed via transcriptome analysis to determine the effects of low- and high-iron diets on transcriptome levels. Correlation analysis was performed for apparent serum parameters, and transcriptome sequencing was performed using weighted gene co-expression network analysis to reveal the key pathways underlying hypoxia regulation and iron metabolism. The main results are as follows. (1) Except for the hypoxia-inducible factor 1 (HIF-1) content (between the low- and high-iron groups), significant differences were not observed among the serum iron metabolic parameters. The serum HIF-1 content of the low-iron group was significantly higher than that of the high-iron group (p < 0.05). (2) Sequencing analysis of the liver transcriptome revealed 155 differentially expressed genes (DEGs) between the low-iron and control groups, 229 DEGs between the high-iron and control groups, and 279 DEGs between the low- and high-iron groups. Bioinformatics analysis showed that the HIF-1 and transforming growth factor-beta (TGF-ß) signaling pathways were the key pathways for hypoxia regulation and iron metabolism. Four genes were selected for qPCR validation, and the results were consistent with the transcriptome sequencing data. In summary, the serum iron metabolism parameter results showed that under the influence of low- and high-iron diets, Wujin piglets maintain a steady state of physiological and biochemical indices via complex metabolic regulation of the body, which reflects their stress resistance and adaptability. The transcriptome results revealed the effects of low-iron and high-iron diets on the gene expression level in the liver and showed that the HIF-1 and TGF-ß signaling pathways were key for regulating hypoxia adaptability and iron metabolism homeostasis under low-iron and high-iron diets. Moreover, HIF-1α and HEPC were the key genes. The findings provide a theoretical foundation for exploring the regulatory pathways and characteristics of iron metabolism in Wujin pigs.

[Finite element analysis of a new shape memory alloy cervical hook for atlantoaxial instability].

The mechanics of a new shape memory alloy cervical hook for atlantoaxial instability was analyzed with finite element method on the basis of a three-dimensional model reconstructed from the images of CT scanning of an adult cadaveric upper cervical at 1-mm interval. The stress and displacement of every nodule and element in the course of deformation of the internal fixation were tested, and the results showed that the cervical hook was strong enough against tensile stress, which concentrates in the middle of the device. The pull was 237.58 N at the loading point. With such mechanical performance, this cervical hook can be reliable for correction of atlantoaxial instability.

[Study of three-dimensional computerized reconstruction and CT scanning with thin slice after filling hepatic duct system].

OBJECTIVE: To establish the modal of perfusing and casting in hepatic duct system and explore the methods of three dimensional reconstruction with CT scanning image after filling hepatic duct. METHODS: All canal of livers with integral porta hepatic were perfused with various filling material after pretreatment, then fixed and casted. Hepatic preparations that had been perfused were put into the model of modelling abdominal cavity and scanned with thin slice. The three dimensional duct structures of hepatic with three methods of MIP, SSD and computerized treatment. RESULTS: Fourteen hepatic samples were filled and casted. Nine hepatic samples were scanned with slice height 1.0 mm, all 2514 slice images and average 279 images. Five hepatic samples were scanned with slice height 3.0 mm, all 512 slice images and average 102 images. Intrahepatic vein and portal vein system of three dimensional reconstruction were seen clearly with MIP method. The three dimensional established three dimensional images with SSD method was shown much stronger than that of MIP method. The three dimensional images of hepatic solid and hepatic vein system were established with method of comperized treatment. Vary three dimensional shape of hepatic solid and hepatic vein was obtained through different direction rotational. CONCLUSIONS: The modal filled and casted hepatic duct system were practise. The images established three dimensional with methods of MIP, SSD and comperized treatment were seen clearly. The modal and images of thin slice CT scanning are a better method for researching hepatic duct system.