1.Ethic Problems of Animal Experiments
Chinese Medical Ethics 1994;0(05):-
Animal experiments play an important role in development of biomedicine.But with the rise of aniaml protection,animal experiments are suffering the challenge from the theory on animal rights and animal welfare act.The theory about animal rights is a genre of ecoethics,which claims animal has congenital survival and freedom rights as well as human.Medicine people should have scientific,serious and humane attitudes to take aniaml experiments.
2.Relationship between high mobility group box-1 protein and inflammation
Wanghua LIU ; Hua LI ; Xianzhong XIAO
Chinese Journal of Pathophysiology 2000;0(08):-
High mobility group box-1(HMGB1)distributed widely.It exists in many organs.HMGB1 locates in nuclei and cytoplasm in normal condition.It involves in many activity of life(i.e.,duplication of DNA,cellular differentiation,gene expression).The immunocytes(i.e.,mononuclear macrophage and dendritic cells)secrete HMGB1 into the extracellular milieu when stimulated with LPS and cytokines.It acts as proinflammatory cytokines,activates inflammatory and immunological responses.As a late mediators of inflammation and last long,HMGB1 plays an important role in sepsis,so it may be a convenient and practical index in evaluating severity of sepsis and may be an important and new therapeutic target in sepsis.It has been initially proved in experimental and clinical study.
3.Pathophysiological function of HMGB1 as a late-acting mediator of inflammation
Daolin TANG ; Rui KANG ; Xianzhong XIAO
Chinese Journal of Pathophysiology 2000;0(07):-
High mobility group box chromosomal protein (HMGB1), an abundant eukaryotic nonhistone chromosomal protein, is previously known as a nuclear DNA-binding protein that stabilizes the structure and function of chromatin, regulates gene transcription. Recent studies identify that extracellular HMGB1 as a late mediator of endotoxemia and sepsis.HMGB1 is released by activated macrophages,induces the release of other proinflammatory mediators,and mediates lethality when overexpressed. It may also be a key signal for eliciting immune responses to cellular injury and death.Moreover,the late kinetics of HMGB1,in compared with other proinflammatory cytokines such as TNF and IL-1,suggest that targeting HMGB1 may provide a wide and clinically accessible therapeutic window.Three independent strategies to inhibit HMGB1 release and action are now available:anti-HMGB1 antibodies,A box,and ethyl pyruvate. This review covers the general features of HMGB1 and progress in research on its newly role as a cytokine participating in the development of sepsis.
4.Protective effect of Allicin on intestinal mucosal barrier of septic rats
Min GAO ; Xuefei XIAO ; Yue PENG ; Xianzhong XIAO ; Mingshi YANG
Chinese Journal of Emergency Medicine 2016;25(2):167-172
Objective To investigate the protective effect of allicin on intestinal mucosal barrier of septic rats so as to explore the possible mechanism.Methods Twenty-four male SD rats were randomly (random number) divided into sham,septic model and allicin treatment group.Septic model was established by cecal ligation and puncture (CLP) in rats.Rats in the treatment group were administered with allicin (30 mg/kg,ip)at 6 h and 12 h after modeling,while those in the model and sham groups were treated with equal amount of saline instead.Rats were sacrificed at 24 h and the serum D-lactic acid,diamine oxidase (DAO) and fluorescence isothiocyanate-dextran (FITC-Dextran,FD-40) were determined to evaluate the intestinal mucosal barrier function.The levels of tumor necrosis factor-α (TNF-α),interleukin-6 (IL-6),malondialdehyde (MDA),and the activity of superoxide dismutase (SOD) in intestinal tissue were measured.Histopathological changes of intestinal mucosa injury were assessed by Hematoxylin-eosin staining.Results Compared with the sham group,levels of serum D-lactic acid,DAO and FD-40 increased significantly in the CLP group (D-lactic acid:599.4±101.1 vs.149.2±20.63 nmoL/mL,t=11.84,P<0.01;DAO:302.1 ±64.5 vs.76.57±14.76 ng/mL,t=9.433,P<0.01;FD-40:6664.0±1437.0vs.1446.0±205.0 ng/mL,t =9.704,P <0.01);intestinal morphology damage occurred in the CLP group;intestinal levels of TNF-α,IL-6 and MDA increased greatly (TNF-αt:186.35 ±20.43 vs.58.76 ±8.94 pg/mL,t=17.23,P<0.01;IL-6:763.25±85.23vs.125.36±14.37 pg/mL,t=22.54,P<0.01;MDA:29.36±3.27vs.7.24±0.85 nmol/mg prot,t=16.61,P<0.01),while SOD activity reduced (35.75±6.53 vs.73.26 ±8.35 U/rmg prot,t =10.57,P <0.01) in the CLP group.Allicin treatment greatly inhibited the increase of D-lactic acid,DAO and FD-40 levels in rat plasma caused by CLP (D-lactic acid:330.1 ±81.77 vs.599.4±101.1 nmol/mL,t=7.086,P<0.01;DAO:171.8±49.70vs.302.1±64.56ng/mL,t=5.45,P<0.01;FD-40:3349.0±1167.0 vs.6664.0±1437.0 ng/mL,t=6.165,P<0.01);intestinal morphology damage was improved in the allicin treatment group;allicin treatment greatly inhibited the intestinal levels of TNF-o,IL-6 and MDA and preserved the intestinal SOD activity compared with the CLP group (TNF-α:95.37 ±12.68 vs.186.35 ±20.43 pg/mL,t =12.29,P<0.01;IL-6:354.27±46.27vs.763.25±85.23pg/mL,t=14.45,P<0.01;MDA:16.27±3.14vs.29.36±3.27 nmol/mgprot,t=9.831,P<0.01;SOD:55.35 ±6.23vs.35.75±6.53 U/mgprot,t=5.522,P <0.01).Conclusions Allicin could inhibit local inflammation and oxidative stress in the intestine and exerts protective effect on intestinal mucosal barrier of septic rats.
5.Surface display of phytase on Saccharomyces cerevisiae for efficient bioethanol production from corn starch.
Yan XIAO ; Xianzhong CHEN ; Wei SHEN ; Haiquan YANG ; You FAN
Chinese Journal of Biotechnology 2015;31(12):1700-1710
Production of bioethanol using starch as raw material has become a very prominent technology. However, phytate in the raw material not only decreases ethanol production efficiency, but also increases phosphorus discharge. In this study, to decrease phytate content in an ethanol fermentationprocess, Saccharomyces cerevisiae was engineered forheterologous expression of phytase on the cell surface. The phy gene encoding phytase gene was fused with the C-terminal-half region of α-agglutinin and then inserted downstream of the secretion signal gene, to produce a yeast surface-display expression vector pMGK-AG-phy, which was then transformed into S. cerevisiae. The recombinant yeast strain, PHY, successfully displayed phytase on the surface of cells producing 6.4 U/g wet cells and its properties were further characterized. The growthrate and ethanol production of the PHY strain were faster than the parent S. cerevisiae strain in the fermentation medium by simultaneous saccharification and fermentation. Moreover, the phytate concentration decreased by 91% in dry vinasse compared to the control. In summary, we constructed recombinant S. cerevisiae strain displaying phytase on the cell surface, which could effectively reduce the content of phytate, improve the utilization value of vinasse and reduce the discharge of phosphorus. The strain reported here represents a useful novel engineering platform for developing an environment-friendly system for bioethanol production from a corn substrate.
6-Phytase
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metabolism
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Biofuels
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Ethanol
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chemistry
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Fermentation
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Industrial Microbiology
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Saccharomyces cerevisiae
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metabolism
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Starch
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chemistry
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Zea mays
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chemistry
6.The plasmic translocation and release of high mobility group box chromosomal protein 1 in peripheral blood monocytes of patients with rheumatoid arthritis and the effect of thalidomide
Xiaoxia ZUO ; Yanhui GONG ; Yaou ZHOU ; Hui LUO ; Xianzhong XIAO
Chinese Journal of Internal Medicine 2008;47(5):374-377
Objective To investigate the release and intracellular localization of high mobility group box chromosomal protein 1(HMGBl)in the peripheral blood monocytes of rheumatoid arthritis(RA) patients and the inhibitive effect of thaiidomide.Methods 19 RA patients and 20 healthy controls were included in the study.Monocytes were separated from peripheral blood with Ficoll density gradient centrifugation.Monocytes were treated with 100 ng/ml tumor necrosis factor α(TNFa)or 100 ng/ml TNFα plus 40 μg/ml thalidomide and grown in an incubator at 37℃ with 5%CO,for 24 hours.The cuIture supernatants of the monocytes were collected.HMGB1 level in the culture medium was detected with Western blot.In addition,the intraceUular localization of HMGB1 in the fflonocytes was investigated with immunocytochemical analysis. Results Without stimulation. the release of HMGBl protein was significantly increased in the culture supernatants of peripheral blood monocytes from RA patients as compared with that from healthy controls(P<0.05).TNFα(100 ng/ml)did not further increase the release of HMGBl in the monocytes from the patients with RA.Thalidomide(40 μg/ml)could inhibit the release of HMGB1 in the monocytes from RA patients stimulated with TNFα(P<0.05).In the monocytes from RA patients,HMGBl was mainly localized in the nucleus.Treatment with TNFOL(100 ng/ml)for 24 hour resulted in a cytoplasmic translocation of HMGB1,which was inhibited significantly by thalidomide. Conclusion TNFα induces the release and cytoplasmic translocation of HMGBI in the peTipheral blood monocytes of RA patients and thalidomide inhibits the release and translocation of HMGB1.
7.Discussion on PBL Teaching in Pathophysiology
Chao LI ; Zining LIANF ; Zhizhi TU ; Bimei JIANG ; Xianzhong XIAO
Chinese Journal of Medical Education Research 2006;0(09):-
Problem based learning(PBL) pedagogy has been widely used in medical teaching process.But how to best use and develop PBL teaching,many universities try actively.According to PBL philosophy and the disciplines characteristics,the department of Pathophysiology in Central South University designed and carried out CPBL(Case and Problem Based Learning,CPBL) pedagogy.From the perspective of students,the authors have compared the CPBL pedagogy with PBL pedagogy in other academies,and make some positive recommendations.
8.Investigations on biological functions of heat shock transcription factor 1 (HSF1) using a gene knock out mouse model
Xianzhong XIAO ; Guangwen CHEN ; Jialu YOU ; J.benjamin IVOR
Chinese Journal of Pathophysiology 2001;17(8):793-
HSF1 is the major heat shock transcription factor that binds heat shock element (HSE) in the promoter of heat shock proteins (HSPs) and controls rapid HSP induction in cells subjected to various stresses such as elevated temperature, chemicals, or exposure to toxins. Although at least four members of the vertebrate HSF have been cloned, details of their individual physiological roles remain relatively obscure. To clarify the exact in vivo functions of HSF1 and assess whether HSF1 exhibits redundant or unique roles, we have created homozygous Hsf1-/- mice using standard gene targeting techniques and isolated Hsf1-/- embryonic fibroblasts. Here we demonstrate that heat shock response (HSR) was not attainable in Hsf1-/- embryonic fibroblasts, and this response was required for thermotolerance and protection against heat-induced apoptosis, and that homozygous Hsf1-/- mice, which survived to adulthood according to genetic background, exhibited multiple phenotypes including: (1) placental defects that reduced embryonic viability after late midgestation (day 13.5); (2) growth retardation; (3) female infertility caused by preimplantation lethality, and (4) increased mortality (+/+ vs -/-, P<0.05) and exaggerated production of proinflammatory cytokine, TNF α (+/- vs -/-, P<0.05) after endotoxin challenge. Interestingly, although Hsf1-/- mice exhibited placental defects and embryonic death, basal HSP expression is not appreciably altered during embryonic development by the HSF1 null mutation, suggesting this factor might be involved in regulating some non-HSP genes or signaling pathways which may be important for development. Taken together, our results established direct causal effects for the HSF1 transactivator in regulating diverse physiological and pathophysiological conditions such as developnent, growth, reproduction, apoptosis and sepsis. The present work also provided a useful mammalian model for further investigating the implications of Hsf1 and its target genes (HSPs and other possible non-HSP genes) in various physiological and pathophysiological processes.
9.Effect of nucleolin on cardiac cell apoptosis in Type 2 diabetic cardiomyopathy mice
Meidong LIU ; Li SUN ; Bimei JIANG ; Sipin TAN ; Ke LIU ; Xianzhong XIAO
Journal of Central South University(Medical Sciences) 2017;42(3):241-245
Objective:To investigate the effect of nucleolin on cardiac cell apoptosis in Type 2 diabetic cardiomyopathy mice.Methods:Mice were fed with high-fat and high-sugar food for 20 weeks (mice were injected intraperitoneally with 60 mg/kg streptozotocin in the 5th and 6th weeks) to establish a mouse model of Type 2 diabetes.The mice were divided into 4 groups:a wild type (WT) control group,a nucleolin transgenic (TG) control group,a WT diabetic group,a TG diabetic group.Diabetesrelated indicators were detected at the end of the 8th week.At the end of the 20th week,HE staining was used to observe myocardial morphological changes;TUNEL staining and caspase-3 activity were used to detect the extent of apoptosis of cardiac myocytes.Results:The level of fasting blood glucose was significantly increased in the diabetic group than that in the control group.In WT diabetic group,myocardial disarrangement,fragmentation and dissolution were observed (determined by HE staining);cellular apoptosis (determined by TUNEL staining and caspase-3 activity) also increased markedly in the WT diabetic group.Compared with the wild mice in the diabetic group,myocardial morphological changes and cardiac myocytes apoptosis were alleviated significantly.Conclusion:Nucleolin overexpression affectes the occurrence and development of diabetic cardiomyopathy through inhibition of cardiac myocyte apoptosis.
10.Measurement of serum lipopolysaccharide binding protein for diagnosis and prognosis prediction in septic patients
Jing JIAO ; Yu JIANG ; Min GAO ; Nian WANG ; Mingshi YANG ; Xianzhong XIAO
Chinese Journal of Pathophysiology 2015;(7):1294-1299
AIM:To investigate the role of lipopolysaccharide binding protein (LBP) for diagnosis and prog-nosis prediction in the septic patients.METHODS:A total number of 80 ICU patients were enrolled.The patients were divided into systemic inflammatory response syndrome ( SIRS) group and sepsis group, the patients in sepsis group were di-vided into non-survivor sub-group and survivor sub-group.We collected the serum samples and analyzed acute physiology and chronic health evaluation ( APACHE) II score on the first day of the patients hospitalized in ICU.In addition, we also selected 10 healthy volunteers and collected their serum samples.The serum concentrations of LBP, C-reactive protein ( CRP) and procalcitonin ( PCT) were measured by ELISA.ROC analysis of LBP, CRP, PCT and APACHE II score was conducted to discriminate among critically ill patients with sepsis and predict the prognosis of the patients with sepsis.RE-SULTS:The levels of the 4 indicators in the septic patients were higher than those in the patients of SIRS (P<0.05).In addition, serum LBP and APACHE II score in the non-survivor sub-group were higher than those in the survivor sub-group (P<0.05), whereas no difference of the PCT and CRP levels between survivors and non-survivors with sepsis was ob-served.LBP levels greater than 26.84 mg/L had 97.1% sensitivity and 95.9% specificity to discriminate between SIRS and sepsis.LBP levels greater than 54.16 mg/L had 85.2%sensitivity and 80.0%specificity for prognosis of unfavorable outcome.CONCLUSION:LBP level was more accurately correlated with diagnosis or prognosis prediction than CRP or PCT in patients with sepsis.