1.Three-dimensional finite element models of advancement skin flap and simulation analysis based on skin biomechanical features
Zhao ZHANG ; Jie LUAN ; Zuojun JING ; Guanyi LI ; Yujing LI
Chinese Journal of Medical Aesthetics and Cosmetology 2011;17(2):121-124
Objective To build three-dimensional (3-D) finite element models for local advancement skin flap, by which the post-operative local strain and local stress of skin were figured out to assist in the design of skin flap in clinic. Methods The biomechanical parameters of human forehead skin were obtained in vitro from biomechanical experiments. The 3-D finite element model of local advancement skin flap was set up by MSC Marc/Mentat 2005 (3-D finite element software). Six models were built with the same flap but different skin defects, to simulate post-operative local strain of skin and local stress of skin in different models. Results Post-operative local stress of skin increased with the skin flaps stretching, but the relationship between increase and stretching did not meet the linear rule. Skin flap was able to stretch to 40 % of its initial length in theory if we did not consider blood supply of it. When the skin flap stretched over 40 % of its initial length, the maximal stress could exceed the yield limit. Conclusion It is an effective and workable way to simulate local advancement skin flap using 3-Dfinite element model and biomechanical parameters of human skin. The stretch ratio of local advancement skin flap should be not over 40% for safety.
2.Expression and clinical significance of Survivin and MHC in non-small cell lung cancer
Xigui YANG ; Zupeng LUAN ; Huazhi ZHANG ; Yujing ZHAN ; Qingmei TIAN
Journal of International Oncology 2009;36(1):69-72
Objective To explore the expression of Survivin and MHC in non-small cell lung cancer (NSCLC), and their interaction.Methods A total of 40 patients with histologically diagnosed NSCLC were enrolled in this study.Control samples were consisted of normal lung tissues from 15 patients.Expression of Survivin and MHC were detected by flow cytometry in 40 non-small cell lung cancer tissues and 15 normal lung tissues.Results The positive rates of Survivin protein expression in NSCLC tissues classified stages Ⅰ,Ⅱ and Ⅲ were 28.57% ,30.77% and 80.00% respectively.There was a correlation between Survivin protein expres-sion and stages of NSCLC.Survivin protein expression was detected in 19 of 29 patients with lymph node metas-tasis, and 3 of 11 patients with no metastasis.There was a statistically significant difference between the two groups (P<0.030).The loss expression rates of MHC-Ⅰ in NSCLC tissues of low grade,intermediate grade and high grade were 84.62% ,42.10% and 37.50% respectively.There was a correlation in expression be-tween MHC-Ⅰ and tumor grade.The positive rates of MHC-Ⅱ expression in NSCLC tissues was related to pa-thology type (P=0.005).The expression in squamous cancer and non-squamous non-adno cancer was lower than that of adenocarcinoma (P=0.002, P=0.04).There was no obvious correlation between the expression of Survivin and MHC-Ⅰ,MHC-Ⅱ in NSCLC.Conclution The expression of Survivin and MHC could be in-volved in the pathogenesis and development of NSCLC, and the combined detection will predict the prognosis of the patients with NSCLC.
3.Determination of dexamethasone in human plasma by solid phase extraction with ultra performance liquid chromatography-tandem mass spectrometer
Yujing LUAN ; Ruihua WANG ; Ying DONG ; Leiping ZHANG ; Zhongshan YU
Chinese Journal of Forensic Medicine 2017;32(3):297-299
Objective To develop the analytical method to determine the content of dexamethasone in human plasma by solid phase extraction with ultra performance liquid chromatography-tandem mass spectrometer. Methods The human plasma was extracted with a solid phase extraction(SPE) and determined by UPLC-MS/MS. LC-MS/MS was performed in ESI source with MRM mode for quantification. Results The lowest detectable limit was 0.05ng/mL, the linear range was 1~100ng/mL. The absolute recovery was more than 78.1%. The intra- and inter day precision was within 15% at three concentrations. Conclusion Since the procedure proved to be simple, quick and effective, it could be used for the determination of dexamethasone in human plasma.
4.Determination of dexmedetomidine in human plasma by solid phase extraction with gas chromatography-mass spectrometry
Ruihua WANG ; Rui LIU ; Yujing LUAN ; Ying DONG ; Xinxin REN
Chinese Journal of Forensic Medicine 2017;32(5):497-499
Objective To develop the analytical method of dexmedetomidine in human plasma by solid phase extraction with gas chromatography-mass spectrometry(SPE-GC/ MS). Methods The human plasma were extracted with a solid phase extraction(SPE) and determined by GC/MS. Results The lowest detectable limit was 0.05μg/mL, the standard curve was linear over the range of 0.2μg/mL~5μg/mL. The absolute recovery was 86.1%~91.5%. The intra-and interday precision was within 7.86% at three concentrations. Conclusion Since the procedure proved to be simple, quick and sensitive, it could be used for the determination of dexmedetomidine in human plasma.
5.Rapid detection of oleandrin and adynerin in human blood by HPLC-MS/MS
Rui SONG ; Jifeng WU ; Haiyan LIU ; Yujing LUAN
Chinese Journal of Forensic Medicine 2017;32(5):514-517
Objective To establish the analytical method of oleandrin and adynerin in human blood by HPLC-MS/MS. Methods After protein sediment by acetonitril, the concentrations of oleandrin and adynerin in human blood were quantitatively determined by HPLC-MS/MS. The qualitative analysis was conducted based on retention time and MRM ions. Besides, the standard curve method was used for quantification. Results The detection limits of both oleandrin and adynerin were 0.5ng/mL, the linear range was from 1ng/mL to 1mg/mL, with a recovery rate of 75.2%~95.7%. Conclusion The detecting protocol has the advantages of high sensitivity, fast and high accuracy with a relatively wide linear range, which is especially suitable for rapid detection of oleander toxins, alexandrine and adynerin in particular, in human blood in poisoning cases.
6.The expression difference between estrus and non-estrus of ERβmRNA of beagles by real-time quantitative PCR
Rui ZHONG ; Yi GAN ; Xiumei REN ; Qin XU ; Yanbin ZHAO ; Bing LIU ; Zhaozeng SUN ; Yujing ZHU ; Xinhong LUAN ; Zhongming HU ; Yong ZHANG ; Lin ZENG
Chinese Journal of Comparative Medicine 2014;(11):15-19
Objective To quantitative the changing information of estrogen receptor βgene which was in tissue and organ of sex gland during oestrus and dioestrus of Beagles, and to show the different expression situation of hypothalamus-pituitary-gonad axis during oestrus and dioestrus, and providing the basic of theory to research deeply the mechanism of heat of Beagles. Methods As the key gene in regulation reproduction, ERβgene is located in hypothalamus-pituitary-gonad axis, so using Beagles which was in oestrus and dioestrus, and extract the RNA from hypothalamus、pituitary、ovary and uterus respectively,after reverse transcription we detected the expression of ERβgene by real-time quantitative PCR.Results The expression of ERβgene mRNA from ovary、uterus、pituitary、hypothalamus of Beagles which was in dioestrus was 0.35 times, 0.17 times, 0.44 times and 0.43 times than the expression of ERβgene mRNA from ovary, uterus, pituitary, hypothalamus of Beagles which was in oestrus.Conclusion The expression of ERβgene was up-regulation in hypothalamus-pituitary-ovary axis of Beagles which was in oestrus.
7.Detection of 13 Paralytic shellfish toxins in human whole blood by high-performance liquid chromatography-tandem mass spectrometry
Xiuqin MA ; Qiang JIE ; Yujing LUAN ; Zeyu WANG ; Fanglin WANG
Chinese Journal of Forensic Medicine 2024;39(4):458-461,466
Objective To establish the analysis method of 13 Paralytic shellfish toxins(PSTs)in human whole blood by high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).Methods 13 kinds of PSTs were extracted from the whole blood using acetonitrile with 1%acetate(1︰3,v︰v)solution,and separated by UPLC BEH Amide chromatographic column(100mm×2.1mm,1.7μm).The samples were detected by an electrospray ionization source(ESI)and positive and negative ion multiple reaction monitoring(MRM)mode,and quantified by matrix matching curve external standard method.Results The results showed that 13 kinds of PSTs in blood samples were linear well in the ranges of 1~100 ng/mL,with the correlation coefficient(r2)>0.995.The limit of detection(LODs)of the method were 0.5~2 ng/mL,the limit of quantitation(LOQs)were 1~4 ng/mL,and the recoveries of the method were 65.55%~114.12%.Conclusion The method is highly sensitive,reproducible,and can qualify and quantify thirteen toxins at the same time,which is suitable for the rapid detection of PSTs in whole blood samples.