1.The effect of NAD kinase homologues on the beta-oxidation of unsaturated fatty acids with the double bond at an even position in Saccharomyces cerevisiae.
Chinese Journal of Biotechnology 2006;22(4):667-671
ATP-NAD kinase phosphorylates NAD to produce NADP by using ATP, whereas ATP-NADH kinase phosphorylates both NAD and NADH. Three NAD kinase homologues, namely, Utr1p, Pos5p and Utr1p, exist in the yeast Saccharomyces cerevisiae, which were all confirmed as ATP-NADH kinases and found to be important to supply NADP(H) for yeast cells. In S. cerevisiae, fatty acid beta-oxidation is restricted to peroxisomes and peroxisomal NADPH is required for beta-oxidation of unsaturated fatty acids with the double bonds at even positions. Single and double gene disruption strains of NAD kinase genes, i.e., utr1, pos5, yef1, utr1yef1, utr1pos5 and yef1pos5 were constructed by PCR-targeting method. The utilization ability of these mutants for unsaturated fatty acids with the double bonds at even or uneven positions was examined, with wild type BY4742 as positive control cell, and fatty-acyl-CoA oxidase gene deletion mutant (fox1) and peroxisomal NADP-dependent isocitrate dehydrogenase isoenzymes gene deletion mutant (idp3) as negative control cells. The results indicated that the NAD kinase homologues, especially Pos5p, were critical for supplying NADP and then NADPH in peroxisomal matrix. NADP, which was supplied mainly by Utr1p, Pos5p and Yef1p, particularly by Pos5p, was proposed to be able to transfer from outside of peroxisome into peroxisomal matrix and then converted to NADPH by Idp3p.
Fatty Acids, Unsaturated
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metabolism
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Mitochondrial Proteins
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physiology
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NADP
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metabolism
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Oxidation-Reduction
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Phosphotransferases (Alcohol Group Acceptor)
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physiology
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Saccharomyces cerevisiae
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growth & development
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metabolism
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Saccharomyces cerevisiae Proteins
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physiology
2.A new clinical classification of hepatolithiasis based on biliary anatomy and pathology
Shifeng FU ; Shihua HUANG ; Chunman LI ; Nan XIE ; Lei WEI ; Gang LI ; Ming HU ; Quanying LIU ; Bimang FU
Chinese Journal of General Surgery 2019;34(5):384-388
Objective To investigate a new clinical classification of hepatolithiasis based on biliary anatomy and pathology in order to guide clinical decision-making.Methods The cases of hepatolithiasis admitted to our hospital from Mar 2015 to Aug 2018 were classified into six types and an additional type according to biliary anatomy,stone site and extent,liver pathological changes,and Oddi sphincter function.Results Of the214 cases of hepatolithiasis,5 cases (2.3%) were type Ⅰ;41 cases (19.2%) were type Ⅱ;76 cases (35.5%) were type Ⅲ;17 cases (7.9%) were type Ⅳ;29 cases (13.5%) were type Ⅴ;46 cases (21.5%) of type Ⅵ.The most common complication was incision infection (28 cases,13.1%),liver failure 0,and perioperative death 0.During the follow-up from 3 months to 3 years,there were 14cases of stone recurrence,the recurrence rate was 7.6%.Conclusion This classification scheme and the "individualized precise anatomical combined hepatectomy or segmental hepatectomy" based on this classification is safe and effective while enhancing the cure rate.
3.Biomechanical characteristics of thoracic T10 bone tumor metastasis at different locations:three-dimensional finite element analysis
Guoren XIA ; Hao YU ; Shifeng JIANG ; Xin PENG ; Xiao FU ; Qi CHEN ; Lizhuang YANG ; Tengfei WANG ; Hai LI
Chinese Journal of Tissue Engineering Research 2024;28(36):5759-5765
BACKGROUND:With the innovation of examination technique,the number of patients with spinal metastases in different stages is increasing year by year.Percutaneous vertebroplasty is an important treatment for spinal metastases;however,there is no report on the biomechanical effect in different stages and different activities after operation. OBJECTIVE:To simulate thoracic T10 bone stress and displacement of the different locations of the tumor metastasis based on the three-dimensional finite element model. METHODS:According to thoracic three-dimensional CT images of a 30-year-old healthy male,Mimics software was used to construct a three-dimensional geometric model of thoracic vertebrae(T9-T11),including ribs,ligaments and intervertebral discs.Three-dimensional models of T9-T11 vertebral bodies and different parts of the posterior thoracic vertebrae invaded by thoracic metastatic tumors were simulated,including the control group with intact vertebral structure,unilateral metastasis involving the vertebral body area(experimental group 1),unilateral metastasis involving the vertebral body and pedicle area(experimental group 2),unilateral metastasis involving the vertebral body,pedicle and transverse process area(experimental group 3),and bilateral metastasis involving the vertebral body,pedicle and transverse process area(experimental group 4).Abaqus software was used to create a three-dimensional finite element model.The von Mises stress distribution and the displacement of the model were analyzed under the loading condition,buckling condition,extension condition,and rotation condition. RESULTS AND CONCLUSION:(1)In the study of the maximum total displacement of loading points in different experimental groups under loading,flexion,extension,and rotation conditions,with the increase of metastatic tumor invasion site and invasion surface,the total displacement of loading points increased,and the overall stiffness decreased,especially the total displacement of loading points in experimental group 4 was the largest.(2)Under flexion condition,the maximum Von Mises stress value increased significantly after vertebral body and pedicle destruction,while the maximum Von Mises stress value was almost unchanged when the thoracocostal joint destruction was added.(3)On the basis of finite element analysis and simulation of bone tumor model,the elements in the bone cement region were set as a single set,and the bone cement region was set as the corresponding material properties to simulate bone cement filling.The results showed that the maximum total displacement under loading,flexion,extension,and rotation conditions was less than that of each experimental group.(4)The maximum stress values of the simulated percutaneous vertebroplasty patients in the loading,flexion,extension and rotation conditions were significantly lower than those of the femoral model.(5)It is concluded that the three-dimensional finite element model based on thoracic T9-T11 conducive to the biomechanics characteristics of thoracic vertebrae tumor metastasis,and on the basis of the thoracic vertebrae tumor metastasis model can accurately simulate load point after percutaneous vertebral body under different conditions of total displacement and the maximum Von Mises stress situation.
4.The experience on the construction of the cluster prevention and control system for COVID-19 infection in designated hospitals during the period of "Category B infectious disease treated as Category A"
Wanjie YANG ; Xianduo LIU ; Ximo WANG ; Weiguo XU ; Lei ZHANG ; Qiang FU ; Jiming YANG ; Jing QIAN ; Fuyu ZHANG ; Li TIAN ; Wenlong ZHANG ; Yu ZHANG ; Zheng CHEN ; Shifeng SHAO ; Xiang WANG ; Li GENG ; Yi REN ; Ying WANG ; Lixia SHI ; Zhen WAN ; Yi XIE ; Yuanyuan LIU ; Weili YU ; Jing HAN ; Li LIU ; Huan ZHU ; Zijiang YU ; Hongyang LIU ; Shimei WANG
Chinese Critical Care Medicine 2024;36(2):195-201
The COVID-19 epidemic has spread to the whole world for three years and has had a serious impact on human life, health and economic activities. China's epidemic prevention and control has gone through the following stages: emergency unconventional stage, emergency normalization stage, and the transitional stage from the emergency normalization to the "Category B infectious disease treated as Category B" normalization, and achieved a major and decisive victory. The designated hospitals for prevention and control of COVID-19 epidemic in Tianjin has successfully completed its tasks in all stages of epidemic prevention and control, and has accumulated valuable experience. This article summarizes the experience of constructing a hospital infection prevention and control system during the "Category B infectious disease treated as Category A" period in designated hospital. The experience is summarized as the "Cluster" hospital infection prevention and control system, namely "three rings" outside, middle and inside, "three districts" of green, orange and red, "three things" before, during and after the event, "two-day pre-purification" and "two-director system", and "one zone" management. In emergency situations, we adopt a simplified version of the cluster hospital infection prevention and control system. In emergency situations, a simplified version of the "Cluster" hospital infection prevention and control system can be adopted. This system has the following characteristics: firstly, the system emphasizes the characteristics of "cluster" and the overall management of key measures to avoid any shortcomings. The second, it emphasizes the transformation of infection control concepts to maximize the safety of medical services through infection control. The third, it emphasizes the optimization of the process. The prevention and control measures should be comprehensive and focused, while also preventing excessive use. The measures emphasize the use of the least resources to achieve the best infection control effect. The fourth, it emphasizes the quality control work of infection control, pays attention to the importance of the process, and advocates the concept of "system slimming, process fattening". Fifthly, it emphasizes that the future development depends on artificial intelligence, in order to improve the quality and efficiency of prevention and control to the greatest extent. Sixth, hospitals need to strengthen continuous training and retraining. We utilize diverse training methods, including artificial intelligence, to ensure that infection control policies and procedures are simple. We have established an evaluation and feedback mechanism to ensure that medical personnel are in an emergency state at all times.
5.Simultaneous quantification of ginsenoside Rg1 and its metabolites by HPLC-MS/MS: Rg1 excretion in rat bile, urine and feces.
Chiyu HE ; Ru FENG ; Yupeng SUN ; Shifeng CHU ; Ji CHEN ; Chao MA ; Jie FU ; Zhenxiong ZHAO ; Min HUANG ; Jiawen SHOU ; Xiaoyang LI ; Yuzhu WANG ; Jinfeng HU ; Yan WANG ; Juntian ZHANG
Acta Pharmaceutica Sinica B 2016;6(6):593-599
Ginsenoside Rg1 (Rg1), the major effective component of ginseng, has been shown to have multiple bioactivities, but low oral bioavailability. The aim of this study was to develop a simple, sensitive and rapid high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, which could be used to validate and quantify the concentrations of Rg1 and its metabolites in Sprague-Dawley rat bile, urine, and feces after oral administration (25 mg/kg). Calibration curves offered satisfactory linearity (>0.995) within the determined ranges. Both intra-day and inter-day variances were less than 15%, and the accuracy was within 80-120%. The excretion recoveries of Rg1, ginsenoside Rh1 (Rh1), and protopanaxatriol (Ppt) in bile, urine, and feces combined were all greater than 70%. The fecal excretion recoveries of Rg1, Rh1, and Ppt were 40.11%, 22.19%, and 22.88%, respectively, whereas 6.88% of Rg1 and 0.09% of Rh1 were excreted in bile. Urinary excretion accounted for only 0.04% of Rg1. In conclusion, the observed excretion profiles for Rg1 and its metabolites after oral administration are helpful for understanding the poor oral bioavailability of Rg1 and will aid further investigations of Rg1 as a pharmacologically active component.