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Jian-Guo Xu

Publications and source records attributed to Jian-Guo Xu.

18 recordsLinked to original sources
PubMed2025

Association of MTHFD1 G1958A (rs2236225) gene polymorphism with the risk of congenital heart disease: a systematic review and meta-analysis.

BACKGROUND: We did this study to better clarify the correlations of methylenetetrahydrofolate dehydrogenase 1 (MTHFD1)-G1958A (rs2236225) gene polymorphism with the risk of congenital heart diseases (CHD) and its subgroups. METHODS: Relevant articles were searched in PubMed, Web of Science, Cochrane Library, Embase, CNKI, VIP database and Wanfang DATA until October 2023. We will use odds ratios (ORs) and 95% confidence intervals (CIs) to examine the potential associations of MTHFD1- G1958A gene polymorphism with CHD and its subgroups. RESULTS: We included a total of 9 eligible studies, encompassing 1917 children with CHD, 1863 healthy children, 1717 mothers of the children with CHD and 1666 mothers of healthy children. In our study, the meta-analysis of fetal group revealed no significant association between any of the five genetic models for the MTHFD1-G1958A polymorphism and the risk of CHD. Subgroup analysis showed that associations between the MTHFD1-G1958A polymorphism and Tetralogy of Fallot (TOF) risk in the homozygote model (AA vs. GG, OR = 2.82, 95%CI [1.16, 6.86], P = 0.02) and recessive model (AA vs. GG + GA, OR = 3.09, 95%CI [1.36, 7.03], P = 0.007). In addition, the MTHFD1-G1958A polymorphism was associated with the risk of CHD in racial subgroup, increasing the risk of CHD in Caucasians. In maternal analysis, 2 genetic models of MTHFD1-G1958A polymorphism increased the risk of CHD: the heterozygote model (GA vs. GG, OR = 1.22, 95%CI [1.04, 1.42], P = 0.01), and the dominance model (GA + AA vs. GG, OR = 1.17, 95%CI [1.01, 1.34], P = 0.03). CONCLUSIONS: The fetal MTHFD1-G1958A (rs2236225) gene polymorphism increase their risk of TOF. The maternal MTHFD1-G1958A polymorphism has a strong correlation with the risk of CHD, and there are racial differences in this correlation. Compared with GG genotype, the GA genotype increases the risk of CHD.

Humans↗
PubMed2006

Influence of age and sex on pharmacodynamics of propofol in neurosurgical patients: model development.

AIM: To determine propofol concentration in the cerebral spinal fluid (CSF) of neurosurgical patients and carry out a preliminary population pharmacodynamic study. METHODS: Twenty-seven elective neurosurgical patients (12 men and 15 women) aged 17-74 years received propofol in a bolus dose of 2 mg/kg for 5 min and an infusion of 10 mg/kg per h for 5 min. Frequent CSF samples were drawn and assayed for propofol concentration. The bispectral index (BIS) was used to measure the drug effect. All data were analyzed first with the Excel software package, then pharmacodynamics modeling was performed using the NONMEM software package. RESULTS: The CSF concentration was related to the drug effect with linear and sigmoid Emax models. The parameters for the linear addictive model were a=1.11 and b=95.4. The parameters for the linear exponential model were a=1.05 and b=92.7. The parameters for the sigmoid E(max) model were E(max)=119, EC(50)=53.6 ng/mL, and N=1.51. When the covariates of age, weight and sex were considered, the parameters of models, objective function, the standard error of the mean and the prediction error were not optimized. CONCLUSION: Linear additive, linear exponential and sigmoid E(max) models can be used to describe the pharmacodynamics of propofol with respect to the concentration in CSF. In this small population, age (17-74 years), weight (47-98 kg) and sex did not influence any of the pharmacodynamic parameters of propofol. To verify these preliminary results, a larger study population is required.

Adolescent↗
PubMed2006

Cytolethal distending toxin in Escherichia coli O157:H7: spectrum of conservation, structure, and endothelial toxicity.

We identified the cytolethal distending toxin V (CDT-V) gene cluster in 19 (4.9%) of 391 enterohemorrhagic Escherichia coli O157:H7. cdt-V+ strains belonged to five phage types (PTs) and were most frequent within PTs 14 and 34. CDT-V was expressed in all but two cdt-V+ strains and was lethal to cultured endothelial cells. Subtyping schemes should include cdt-V as a marker to differentiate E. coli O157:H7 even within the same phage type.

Alleles↗
PubMed2006

Hydroxyethyl starch exhibits antiinflammatory effects in the intestines of endotoxemic rats.

We performed the present in vivo study to investigate the effect of hydroxyethyl starch (HES) on intestinal production of inflammatory mediators and activation of transcription factors during endotoxemia. Rats with endotoxemia induced by lipopolysaccharide (LPS) (5 mg/kg, IV) were treated with HES (16 mL/kg, IV) or saline (64 mL/kg, IV). At 2, 3, or 6 h after the LPS challenge, the rat ileal tissues were collected. Various ileal inflammatory mediator levels (tumor necrosis factor-alpha, interleukin [IL]-6, cytokine-induced neutrophil chemoattractant-1, and IL-10), inflammatory mediator messenger RNAs (mRNAs), activities of nuclear factor (NF)-kappaB and activator protein (AP)-1, and ileal myeloperoxidase-positive cells were determined in each group. HES significantly reduced the increased intestinal levels of tumor necrosis factor-alpha, IL-6, cytokine-induced neutrophil chemoattractant-1, and the mRNAs in the endotoxemic rats. Similarly, HES could decrease the myeloperoxidase-positive cells induced by LPS and also inhibit ileal NF-kappaB and AP-1 activations. Our results suggest that during endotoxemia HES may down-regulate intestinal inflammatory mediator production, and this antiinflammatory effect of HES may act through suppression of NF-kappaB and AP-1 activations.

Animals↗
PubMed2005

Inhibition of p38 mitogen-activated protein kinase may decrease intestinal epithelial cell apoptosis and improve intestinal epithelial barrier function after ischemia- reperfusion injury.

AIM: To investigate the role of p38 mitogen-activated protein kinase in rat small intestine after ischemia-reperfusion (I/R) insult and the relationship between activation of p38 MAPK and apoptotic cell death of intestine. METHODS: Ninety Wistar rats were divided randomly into three groups, namely sham-operated group (C), I/R vehicle group (R) and SB203580 pre-treated group (S). In groups R and S, the superior mesenteric artery (SMA) was separated and occluded for 45 min, then released for reperfusion for 0.25, 0.5, 1, 2, 6, 12 and 24 h. In group C, SMA was separated without occlusion. Plasma D-lactate levels were examined and histological changes were observed under a light microscope. The activity of p38 MAPK was determined by Western immunoblotting and apoptotic cells were detected by the terminal deoxynucleotidyl transferase (TdT)-mediated dUDP-biotin nick end labeling (TUNEL). RESULTS: Intestinal ischemia followed by reperfusion activated p38 MAPK, and the maximal level of activation (7.3-fold vs sham-operated group) was reached 30 min after I/R. Treatment with SB 203580, a p38 MAPK inhibitor, reduced intestinal apoptosis (26.72+/-3.39% vs 62.50+/-3.08% in I/R vehicle, P<0.01) and decreased plasma D-lactate level (0.78+/-0.15 mmol/L in I/R vehicle vs 0.42+/-0.17 mmol/L in SB-treated group) and improved post-ischemic intestinal histological damage. CONCLUSION: p38 MAPK plays a crucial role in the signal transduction pathway mediating post-ischemic intestinal apoptosis, and inhibition of p38 MAPK may attenuate ischemia-reperfusion injury.

Animals↗
PubMed2005

Effect of glutamate on inflammatory responses of intestine and brain after focal cerebral ischemia.

AIM: To study the modulation of glutamate on post-ischemic intestinal and cerebral inflammatory responses in a ischemic and excitotoxic rat model. METHODS: Adult male rats were subjected to bilateral carotid artery occlusion for 15 min and injection of monosodium glutamate intraperitoneally, to decapitate them at selected time points. Tumor necrosis factor alpha (TNF-alpha) level and nuclear factor kappa B (NF-kappaB) activity were determined by enzyme-linked immunosorbant assay (ELISA) and electrophoretic mobility shift assay (EMSA), respectively. Hemodynamic parameters were monitored continuously during the whole process of cerebral ischemia and reperfusion. RESULTS: Monosodium glutamate (MSG) treated rats displayed statistically significant high levels of TNF-alpha in cerebral and intestinal tissues within the first 6 h of ischemia. The rats with cerebral ischemia showed a minor decrease of TNF-alpha production in cerebral and intestinal tissues. The rats with cerebral ischemia and treated with MSG displayed statistically significant low levels of TNF-alpha in cerebral and intestinal tissues. These results correlated significantly with NF-kappaB production calculated at the same intervals. During experiment, the mean blood pressure and heart rates in all groups were stable. CONCLUSION: Glutamate is involved in the mechanism of intestinal and cerebral inflammation responses. The effects of glutamate on cerebral and intestinal inflammatory responses after ischemia are up-regulated at the transcriptional level, through the NF-kappaB signal transduction pathway.

Animals↗
PubMed2005

A serological survey on neutralizing antibody titer of SARS convalescent sera.

A seroepidemiologic study was conducted in North China in 2003 to determine the neutralizing antibody titer of severe acute respiratory syndrome (SARS) convalescent sera. A total of 99 SARS convalescent serum samples were collected from patients from the Inner Mongolia Autonomous Region, Hebei Province, and Beijing 35-180 days after the onset of symptoms. The anti-SARS antibodies were detected by enzyme-linked immunosorbent assay (ELISA), neutralization assay, and Western blot. Eighty-seven serum samples were confirmed to be positive for SARS antibodies. The neutralizing antibody titer of the 87 positive sera was analyzed quantitatively by neutralization assay. The geometric mean titer (GMT) of the 87 convalescent sera was 1:61. The Kolmogorov-Smirnov test showed that the neutralizing antibody titers conform to normal distribution, which suggests that the average anti-SARS antibody level in this study was representative of the convalescent antibody level of the SARS population. This result could be useful for the development and quality control of SARS vaccines.

Antibodies, Viral↗
PubMed2005

Cerebrospinal fluid and plasma propofol concentration during total intravenous anaesthesia of patients undergoing elective intracranial tumor removal.

OBJECTIVE: The aim of this paper is to compare the propofol concentration in plasma and cerebrospinal fluid (CSF) in patients scheduled for intracranial tumor removal and anaesthetized using propofol as part of a total intravenous anaesthesia technique. METHODS: Twenty-seven patients (ASA I-II) scheduled for elective intracranial tumor removal were studied. Anesthesia was induced with 2 mg/kg propofol for 5 min and infused at 10 mg/(kg x h) for 5 min and then stopped. CSF and arterial blood were collected simultaneously before infusion of propofol and at different time points after infusion of propofol according to bispectral index (BIS) values. Concentrations of propofol in plasma and CSF were measured by HPLC with fluorescence detection. The correlation coefficient and regression equation between plasma and CSF concentration of propofol were worked out by linear simple regression. RESULTS: The propofol CSF concentration that we measured was 1.46% of the plasma concentration. The coefficient of relation between plasma and CSF concentration was 76.7%. CONCLUSIONS: The propofol CSF concentration was positively correlated with and much lower than the plasma concentration. Discrepancies may result from high plasma protein binding of propofol, intracranial pathology and sampling volume.

Adolescent↗
PubMed2004

Ketamine suppresses intestinal NF-kappa B activation and proinflammatory cytokine in endotoxic rats.

AIM: To investigate the protective effect of ketamine on the endotoxin-induced proinflammatory cytokines and NF-kappa B activation in the intestine. METHODS: Adult male Wistar rats were randomly divided into 6 groups: (a) normal saline control, (b) challenged with endotoxin (5 mg/kg) and treated by saline, (c) challenged with endotoxin (5 mg/kg) and treated by ketamine (0.5 mg/kg), (d) challenged with endotoxin (5 mg/kg) and treated by ketamine (5 mg/kg ), (e) challenged with endotoxin (5 mg/kg) and treated by ketamine (50 mg/kg), and (f) saline injected and treated by ketamine (50 mg/kg). After 1, 4 or 6 h, TNF-alpha and IL-6 mRNA were investigated in the tissues of the intestine (jejunum) by RT-PCR. TNF-alpha and IL-6 were measured by ELISA. We used electrophoretic mobility shift assay (EMSA) to investigate NF-kappa B activity in the intestine. RESULTS: NF-kappa B activity, the expression of TNF-alpha and IL-6 were enhanced in the intestine by endotoxin. Ketamine at a dose of 0.5 mg/kg could suppress endotoxin-induced TNF-alpha mRNA and protein elevation and inhibit NF-kappa B activation in the intestine. However the least dosage of ketamine to inhibit IL-6 was 5 mg/kg in our experiment. CONCLUSION: Ketamine can suppress endotoxin-induced production of proinflammatory cytokines such as TNF-alpha and IL-6 production in the intestine. This suppressive effect may act through inhibiting NF-kappa B.

Anesthetics, Dissociative↗
PubMed2004

Protective effect of shen-fu on myocardial ischemia-reperfusion injury in rats.

The present study used in vivo rat heart to investigate (1) whether Shen-Fu (SF), a traditional Chinese formulation comprising Radix Ginseng (RG) and Radix Aconitum Carmichaeli (AC), is protective against myocardium damage due to ischemia-reperfusion injury, and (2) whether the cardioprotective effect of SF is related to scavenging of hydroxyl radicals. The model of ischemia-reperfusion injury was established by ligation of left anterior descending coronary artery for 60 minutes followed by reperfusion for 240 minutes in anesthetized rats. The size of infarction and the pathologic changes of myocardium were observed. Lactate dehydrogenase (LDH) and creatine kinase (CK) in serum, the amounts of malondialdehyde (MDA) and superoxide dismutase (SOD) in myocardium were measured at the end of the reperfusion period. Pretreatment groups with SF (10 mg/kg), RG (9 mg/kg) and AC (1 mg/kg) inhibited the rise in MDA and LDH as well as CK, increased SOD activity, reduced the size of infarction, and improved the pathologic changes of myocardium during ischemia-reperfusion compared with the control group. The effect of SF is better than that of RG and AC. These results indicate that SF, RG and AC protect obviously myocardium against damage due to ischemia-reperfusion in rats. The cardioprotective effect of SF injection may be in part related to scavenging of hydroxyl radicals or inhibition of lipid peroxidation. SF is more effective than its separated herbal extracts prepared from RG and AC.

Aconitum↗
PubMed2004

The effects of hydroxyethyl starch on lung capillary permeability in endotoxic rats and possible mechanisms.

UNLABELLED: In this study we examined the effects of hydroxyethyl starch (HES 200/0.5) on lung capillary permeability in endotoxic rats and explored the possible mechanisms. Male Wistar rats were randomly divided into seven groups treated with saline, lipopolysaccharide (LPS; 6 mg/kg), LPS plus HES (3.75, 7.5, 15, or 30 mL/kg), or HES (30 mL/kg) alone for 4 or 2 h. Lung capillary permeability, lung neutrophil accumulation, expression of CD11b on the blood neutrophil cell surface, lung cytokine-induced neutrophil chemoattractant protein level, and nuclear factor kappa B (NF-kappaB) activation in blood neutrophils and lungs were measured. HES at doses of 3.75 and 7.5 mL/kg significantly reduced LPS-induced increases of lung capillary permeability. HES was found to inhibit lung neutrophil accumulation, cytokine-induced neutrophil chemoattractant protein, and NF-kappaB activation in parallel and to inhibit CD11b expression in a dose-dependent manner. These findings demonstrate that HES has beneficial effects on capillary leak in acute lung injury and that the mechanisms underlying this action involve an antiinflammatory effect of HES, including inhibition of NF-kappaB activation. IMPLICATIONS: A randomized, controlled laboratory experiment indicated that hydroxyethyl starch (HES) could reduce increased lung capillary permeability in endotoxemia. This effect may be due to an antiinflammatory effect of HES.

Animals↗
PubMed2003

Unique physiological and pathogenic features of Leptospira interrogans revealed by whole-genome sequencing.

Leptospirosis is a widely spread disease of global concern. Infection causes flu-like episodes with frequent severe renal and hepatic damage, such as haemorrhage and jaundice. In more severe cases, massive pulmonary haemorrhages, including fatal sudden haemoptysis, can occur. Here we report the complete genomic sequence of a representative virulent serovar type strain (Lai) of Leptospira interrogans serogroup Icterohaemorrhagiae consisting of a 4.33-megabase large chromosome and a 359-kilobase small chromosome, with a total of 4,768 predicted genes. In terms of the genetic determinants of physiological characteristics, the facultatively parasitic L. interrogans differs extensively from two other strictly parasitic pathogenic spirochaetes, Treponema pallidum and Borrelia burgdorferi, although similarities exist in the genes that govern their unique morphological features. A comprehensive analysis of the L. interrogans genes for chemotaxis/motility and lipopolysaccharide synthesis provides a basis for in-depth studies of virulence and pathogenesis. The discovery of a series of genes possibly related to adhesion, invasion and the haematological changes that characterize leptospirosis has provided clues about how an environmental organism might evolve into an important human pathogen.

Bacterial Adhesion↗
PubMed2003

Population pharmacokinetics of propofol in Chinese patients.

AIM: To analyze population pharmacokinetics of propofol in Chinese surgical patients using a nonlinear mixed-effect model (NONMEM) program and to quantitate the effects of covariance of gender, age, and body weight. METHODS: The population pharmacokinetics of propofol was investigated in 76 selective surgical patients (37 males and 39 females aged 19-77 a, weighing 39-86 kg). A total of 1439 blood samples were analyzed using NONMEM (NONMEM Project Group, University of California, San Francisco, CA). Interindividual variability was estimated for clearances and distribution volumes. The effects of age, body weight, and gender were investigated. RESULTS: The pharmacokinetics of propofol in Chinese patients was best described by a three-compartment pharmacokinetic model. Body weight was found to be a significant factor for the elimination clearance, the two inter-compartmental clearances, and the volume of the central compartment. The volumes of the shallow peripheral compartment and deep peripheral compartment remain constant for all individuals. The estimates of these parameters for a 60-kg adult were 1.56 L/min, 0.737 L/min, 0.360 L/min, 12.1 L, 43 L, and 213 L, respectively. For old patients, the elimination clearance and volume of the central compartment decreased. CONCLUSION: The pharmacokinetics of propofol in Chinese patients can be well described by a standard three-compartment pharmacokinetic model. Inclusion of age and body weight as covariances significantly improved the model. Adjusting pharmacokinetics to the individual patients should improve the precision of target-controlled infusion system.

Adult↗
PubMed2002

Inhibition of intracellular calcium elevation and blunting of vasopressor response due to serotonin by ginkgolide B.

The vascular effects of each individual composition in the extract of Ginkgo biloba have not been clarified. In this work, we have investigated whether ginkgolide B (GKB), a terpene lactone component from Ginkgo biloba, modulates intracellular calcium ([Ca (2+)] i) of vascular smooth muscle cells (smc) and how it influences the vasopressor response in vitro caused by serotonin (5-HT). GKB (3.2 - 9.6 microM) selectively decreased serotonin-induced [Ca (2+)] i elevations in cultured smc from bovine aorta in dose-dependent manner, while it had no effects on both resting [Ca (2+)] i and potassium-elicited [Ca (2+)] i elevations. On the other hand, GKB in a concentration of 3.2 - 9.6 microM moderately decreased the maximal pressor efficacy of serotonin by 14 - 45 % in rat mesenteric vascular beds, and the EC50 remained unchanged. The comparison study also showed GKB had no effects on noradrenaline-elicited pressor reactions. These results implicate that GKB may selectively inhibit serotonin-mediated [Ca (2+)] i mobilization in vascular smc and non-competitively alleviate the vasopressor effect of serotonin in vitro.

Animals↗
PubMed2002

[Analysis of gene cluster of Tat-dependent protein export system of Vibrio cholerae and its function].

The Tat (Twin-arginine translocatin) system is a recently defined protein export pathway that serves to translocate folded proteins. The substrates of the Tat pathway contain specific amino-terminal signal peptides that exhibit a conserved amino acid consensus motif-S/T-R-R-x-F-L-X. Here is the report of knocked out the tatA, tatB and tatC genes of the V. cholerae by suicide plasmid homologous recombination technology. Mutant strains showed obvious changes of growth characteristics. The transport of a typical Tat pathway substrate, trimethylamine N-oxide reductase (molybdoenzyme), was completely blocked. The physiochemical reactions of the parent and mutant strains were also analyzed. Four physiochemical reactions using D-galactose, L-asparagine, glyl-L-aspartic acid and D-L-alpha-glycerol phosphate as substrates were negative in mutant strains, which might be affected by the inactivation of the Tat-dependent system.

Asparagine↗
PubMed1998

Changes in erythrocyte membrane ATPases and plasma lipid peroxides in upper abdominal surgery under intravenous procaine-balanced anesthesia.

AIM:To observe the changes in erythrocyte membrane ATPases and plasma lipid peroxides (LPO) patients with in abdominal surgery under intravenous procainebalanced anesthesia.METHODS:By determining the ATPase activities of erythrocyte membrane, effects of upper abdominal surgery under intravenous procaine-balanced anesthesia on the function of erythrocytes were observed in 15 patients undergoing cholecystectomy and gastrectomy (5 males and 10 females, aged 45.9 ± 10.20 years and weighed 60.60kg ± 11.93kg). All patients were free from severe renal,hepatic, pulmonary, cardiac, metabolic and endocrinological diseases and acute infection for at least 2 weeks before surgery. Patients receiving any drug known to affect carbohydrate metabolism prior to anesthesia were excluded from the study.RESULTS:Erythrocyte membrane Na(+), K(+)-ATPase, Mg(2+)-ATPase, Ca(2+), Mg(2+)-ATPase activities were not significantly changed 60min-90min after incision as compared with 30min before anesthesia, but were decreased markedly 10min and 24 hours after completion of operation (P < 0.01). Plasma lipid peroxides (LPO) were increased significantly 24 hours after surgery (P < 0.01) following an initially marked but transient reduction. Plasma LPO changes were not correlated with erythrocyte membrane ATPase activities, r =-0.0396, -0.0097 and 0.4383, respectively (P > 0.05).CONCLUSION:Abdominal surgical trauma under intravenous procaine-balanced anesthesia may be associated with the decreased ATPase activities of erythrocyte membrane and increased LPO in plasma.

Journal Article↗