Red in vivo recombination is a new kind of genetic engineering technique based on homologous recombination. In this work, plasmid pKD46 which expresses Red recombination proteins is transferred into Escherichia coli strain DH5?.The kanamycine resistant gene is generated by PCR by using primers with homology to hisDCB gene of E.coli chromosome. Thus, the hisDCB gene was replaced with kanamycine resistant gene by the plasmid recombination system, then the resistant gene was eliminated by a helper plasmid encoding the FLP recombinase. At last, a E.coli histidine auxotroph which is sensitive to kanamycine was got. The results indicate that Red in vivo recombination is a convenient method to construct auxotrophs.

OBJECTIVETo investigate the role of the key intracellular signaling molecule glycogen synthase kinase-3 beta in the mechanism of liver ischemia reperfusion (IR).

METHODSC57BL/6 mice were subjected to 90 min warm liver cephalad lobe ischemia, followed by various length of reperfusion. Experiment groups included sham control group, liver IRI model group and glycogen synthase kinase-3 beta inhibitor-treated group (SB216763 in DMSO, 25 g/kg, i.p, 2 hour prior to the onset of liver ischemia). The expression of glycogen synthase kinase-3 beta protein was analysed by Western blotting. The serum ALT levels were determined to reflect the function of liver. The affected liver lobes were harvested for histology analysis. The inflammatory gene expression was detected by Quantitative PCR.

RESULTSBy western blot analysis, we found that ischemia itself activated glycogen synthase kinase-3 beta by a significant decrease of its phosphorylation. Glycogen synthase kinase-3 beta inhibitor SB216763-pretreatment ameliorated the liver damages significantly as compared to the controls (sALT: 2046+/-513 U/L vs 5809+/-1689 U/L, P = 0.0153), and suppressed the gene expressions of IL-12, TNFa, IL-1b and IL-6.

CONCLUSIONSThis study demonstrated that the ischemia process modulated liver innate immune activation via a GSK-3-dependent mechanism which favored the development of a pro-inflammation response and lead to liver tissue damages. GSK-3b may be a new therapeutic target to ameliorate liver IRI in transplant patients.

Animals ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Inflammation ; metabolism ; Liver ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Reperfusion Injury ; metabolism ; pathology

OBJECTIVETo determine the mechanism underlying the therapeutic activities of glycogen synthase kinase 3b (GSK3b) against hepatic ischemia-reperfusion (H-IR) injury by investigating the inhibitive effects of GSK3b on inflammation mediated by Toll-like receptor 4 (TLR4).

METHODSC57BL/6 male mice were subjected to 90 min of warm liver cephalad lobe ischemia, followed by reperfusion for various lengths of time. The mice were divided into three groups: the H-IR untreated model (control group), and the H-IR inflammation-induced models that received an intraperitoneal injection of purified lipopolysaccharide (LPS) endotoxin alone (inflammation group) or with pretreatment of the SB216763 GSK3b-specific inhibitor (intervention group). To create a parallel isolated cell system for detailed investigations of macrophages, marrow-derived stem cells were isolated from femurs of the H-IR control group of mice and used to derive primary macrophages. The cells were then divided into the same three groups as the whole mouse system: control, LPS-induced inflammation model, and inflammation model with SB216763 intervention. Differential expressions of inflammation-related proteins and genes were detected by Western blotting and real-time quantitative PCR, respectively.

RESULTSThe phosphorylation levels of ERK, JNK and p38 MAPK were induced in liver at 1 h after reperfusion, but then steadily decreased and returned to baseline levels by 4 h after reperfusion. In addition, the phosphorylation levels of ERK and JNK were induced in macrophages at 15 min after LPS stimulation, while the phosphorylation level of p38 MAPK was induced at 1 h; SB216763 pretreatment suppressed the LPS-stimulated ERK, JNK and p38 phosphorylation in macrophages. In the mouse model, GSK3b activity was found to promote the gene expression of anti-inflammatory cytokine IL-10 (control: 0.21 ± 0.08, inflammation: 0.83 ± 0.21, intervention: 1.76 ± 0.67; F = 3.16, P = 0.027) but to significantly inhibit the gene expression of pro-inflammatory cytokines IL-12 (control: 0.11 ± 0.05, inflammation: 0.85 ± 0.11, intervention: 0.43 ± 0.10; F = 2.67, P = 0.038), TNF-a, (control: 0.052 ± 0.012, inflammation: 8.11 ± 0.98, intervention: 3.9 ± 0.82; F = 4.13, P = 0.016), IL-6 (control: 0.22 ± 0.08, inflammation: 6.37 ± 0.81, intervention: 2.11 ± 0.63; F = 3.21, P = 0.024), and IL-1b (control: 0.12 ± 0.07, inflammation: 2.51 ± 0.62, and intervention: 1.28 ± 0.33; F = 2.22, P = 0.030).

CONCLUSIONInhibition of GSK3b selectively regulates the expression of anti-inflammatory and pro-inflammatory cytokines in liver Kupffer cells (liver macrophages). This process may be one of the mechanisms underlying the ability of GSK3b to ameliorate hepatic ischemia-reperfusion injury, possibly because inhibition of pro-inflammatory cytokines may indirectly mediate liver cell apoptosis.

Animals ; Cells, Cultured ; Cytokines ; metabolism ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Inflammation ; metabolism ; pathology ; Lipopolysaccharides ; adverse effects ; Liver ; pathology ; Macrophages ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Reperfusion Injury ; Toll-Like Receptor 4 ; metabolism

OBJECTIVETo identify independent risk factors for myocardial infarction (MI) in Chinese men and to develop a model to predict risk profile of an individual suffering MI.

METHODSStudy sample included 5 137 men aged 45.2 +/- 7.8 years who came from a cohort in Beijing Capital Steel and Iron Company, based on the three surveys on coronary heart disease conducted in 1974, 1979 and 1980, respectively. Demographic data and other risk factors, such as life style, medical history, blood pressure, total serum cholesterol level (TC), etc. were collected according to the same protocol in 1980. All the participants were followed up for MI in an average period of 20.84 years until 2001.

RESULTS(1) There were 122 cases with MI identified during the period of follow-up, with an incidence of MI 117.4 per 100 000 person-years. Age of more than 50, smoking, higher systolic and diastolic blood pressure (SBP and DBP) levels, higher TC all were identified as important risk factors of MI. (2) Incidence of MI increased with TC. An increment of 0.52 mmol/L of TC significantly increased relative risk of MI by approximately 40% after adjusted for age, blood pressure and smoking. (3) An increment of 20 mm Hg in SBP or 10 mm Hg in DBP associated with a 40% increase in incidence of MI, adjusting for age, TC and smoking. (4) Smoking was the most risky factors for MI. Smokers had 2.3 times risk of MI, after as compared to non-smokers (or its incidence increased by 137%), after adjusting for blood pressure, TC and age, etc. (5) Incidence of MI increased by 20% with increment of five-year of age in those aged over 50 (P < 0.05), after adjusting for blood pressure, TC and smoking. And, (6) finally, based on multivariate logistic and Cox regression analyses, a model containing several risk factors, such as age, blood pressure, TC and smoking, was developed to predict individual's risk for afflicting MI.

CONCLUSIONSResults of this prospective study showed several established risk factors for MI, including age, blood pressure, TC and smoking all as independent predictors of MI in Chinese men. It is clear and rational that intervention and modification of those traditional risk factors can lead to a decrease in coronary events in Chinese population.

Adult ; Age Factors ; Blood Pressure ; physiology ; China ; epidemiology ; Cohort Studies ; Follow-Up Studies ; Humans ; Incidence ; Iron ; Male ; Metallurgy ; Middle Aged ; Multivariate Analysis ; Myocardial Infarction ; epidemiology ; etiology ; Proportional Hazards Models ; Prospective Studies ; Risk Factors ; Smoking ; adverse effects ; Steel ; Triglycerides ; blood

OBJECTIVETo study the relationship between pulmonary surfactant-associated protein B (SP-B) gene polymorphisms and their susceptibility to neonatal respiratory distress syndrome (RDS).

METHODSEighty-eight preterm infants with RDS (RDS group) and 103 infants without RDS (control group) were enrolled. The genomic DNA was isolated using DNA kits. Polymerase chain reaction with restriction fragment length polymorphism technique was used to detect the genotype and allele frequency of the SP-B -18A/C and SP-B 1580C/T single nucleotide polymorphisms. The association between the polymorphisms and RDS was analyzed.

RESULTSSP-B -18A/C and SP-B 1580C/T were found to be polymorphic in both RDS and control groups. The frequencies of CC genotype (X2=12.26, P<0.01) and C allele (X2=11.97, P<0.01) of SP-B 1580C/T were significantly higher in the RDS group than in the control group. The C allele significantly increased the risk of RDS (OR=2.26, 95%CI: 1.42-3.60). The frequencies of genotype and allele of SP-B -18A/C showed no significant difference between the two groups.

CONCLUSIONSSP-B 1580C/T polymorphism contributes to the etiology of RDS and may serve as the susceptibility gene for RDS. The C allele increases the risk of RDS. SP-B -18A/C shows no association with the etiology of RDS.

Genetic Predisposition to Disease ; Genotype ; Humans ; Infant, Newborn ; Polymorphism, Single Nucleotide ; Pulmonary Surfactant-Associated Protein B ; genetics ; Respiratory Distress Syndrome, Newborn ; etiology ; genetics

AIM:To investigate the effect of recombinant bovine basic fibroblast growth factor (rb-bFGF) eye drops and hydroxyl indican eye drops on tear film stability and dry eye symptoms after age-related cataract surgery.METHODS:Totally 80 patients with 80 affected eyes undergoing age-related cataract surgery in our hospital from January 2015 to October 2016 were selected as study subjects,and they were randomly divided into control group and experimental group with 40 patients (40 affected eyes) in each group.The two groups were treated with hydroxyl indican eye drops and rb-bFGF eye drops,respectively.The clinical curative effect,inflammation related factors [interleukin 6 (IL-6),tumor necrosis factor α (TNF-α)],Schirmer test (S Ⅰ t),break-up time (BUT) of tear film,corneal sodium fluorescein staining (FL) and scores of dry eye symptoms in the two groups were observed.RESULTS:The total treatment effective rate of experimental group after treatment was significantly higher than that of the control group (90.0％ vs 72.5％;x2 =4.021,P＜ 0.05).Before treatment,there was no significant difference in IL-6,TNF-α,S Ⅰ t,BUT,FL score and scores of dry eye symptoms between the two groups (P＞0.05).After treatment,IL-6,TNF-α,S Ⅰ t,FL score and scores of dry eye symptoms in two groups significantly decreased while BUT significantly increased (P＜ 0.05),and changes of the indexes were more significant in the experimental group than the control group (P＜0.05).CONCLUSION:In the treatment of patients after age-related cataract after surgery,rb-bFGF eye drops has more advantages over hydroxyl indican eye drops in regulating the expression of inflammatory factors,improving the tear film stability and relieving dry eye symptoms.

Aim To evaluate the effects of different doses of baicalin on rheumatoid arthritis (RA) in SD rats and explore the possible mechanism.Methods Firstly,the model of RA in SD rats was prepared and the hind foot swelling was measured;HE staining was used to observe the pathological changes of the knee joint synovial tissue;RT-qPCR was adopted to determine the mRNA expressions of TLR2 and MyD88 in synovial tissue;Western blot was used to determine the protein expressions of TLR2,MyD88 and NF-κB p65 aher intragastric administration of different doses of baicalin solution.Results Compared with the model,baicalin (60 and 30 mg · kg-1) could inhibit the proliferation of fibroblasts and inflammatory damages in synovial tissue,significantly cut down mRNA expressions of TLR2 and MyD88 (P ＜ 0.05) and markedly reduce protein expressions of TLR2,MyD88 and NF-κB p65 (P ＜ 0.01).Conclusion Baicalin has good effects on RA,which may be realized by inhibiting the activation of TLR2-NF-κB signaling pathway.

OBJECTIVETo evaluate the major causes of death and risk factors among male steelworkers in Beijing.

METHODSThe study included 5137 men from the cohort of Beijing Capital Steel and Iron Company. The baseline survey was performed in 1974, 1979 and 1980 and the final follow-up evaluation was made in 2001 with a mean follow-up of 20.8 years. Causes of death were coded according to the Ninth Revision of International Classification of Diseases (ICD-9). The mortality was calculated by person-years of follow-up and age-standardized according to the 2000 census data in China. Cox proportional-hazards models adjusting for risk factors were used to estimate the relative risk of death.

RESULTSThere is 760 deaths during follow-up. Age-standardized mortality from all causes was 643.0 per 100,000 person-years. The three leading causes of death were malignant neoplasms (mortality, 231.3 per 100,000 person-years), cerebrovascular diseases (mortality, 139.3 per 100,000 person-years) and heart diseases (mortality, 96.4 per 100,000 person-years). The multivariate-adjusted relative risk of death and the population attributable risk proportion for risk factors were as follow: cigarette smoking (95% CI, 1.174 to 1.765); hypertension (95% CI, 1.370 to 1.904) and hypercholesterolemia (95% CI, 1.057 to 1.537).

CONCLUSIONSOur study indicates that malignant neoplasms, cerebrovascular diseases and heart diseases were major causes of death among male steelworkers. Furthermore, cigarette smoking, hypertension and hypercholesterolemia are leading preventable risk factors for death.

Adolescent ; Adult ; Aged ; Cardiovascular Diseases ; mortality ; Cause of Death ; China ; epidemiology ; Follow-Up Studies ; Humans ; Male ; Metallurgy ; Middle Aged ; Neoplasms ; mortality ; Proportional Hazards Models ; Prospective Studies ; Risk Factors ; Stroke ; mortality

OBJECTIVETo elucidate the mechanism of carcinogenesis induced by coke oven emissions by investigating the cell genetic damage index and the methylation of O⁶-methylguanine-DNA methyltransferase (MGMT).

METHODSThe human bronchial epithelial cell 16HBE was treated by 1 µmol/L B(a)P for 48 h, and then was exposed continuously to either 1‰ dimethyl sulfoxide (DMSO) or organic extracts of coke oven emission (OE-COE) for five days at the concentrations of 0, 2.5, 5.0, 10.0 and 20.0 µg/ml. The methylation-specific PCR (MSP-PCR), RT-PCR and immunoblotting were applied to detect the methylation status, changes of mRNA and protein of MGMT, respectively. Single cell gel electrophoresis was used to detect DNA damage induced by OE-COE.

RESULTSCompared with the control group (DMSO), there was a significant hypermethylation in all study groups, along with the suppression of mRNA and protein in a dose-dependent manner, and the gradation ratio of them was 1.0, 0.96, 0.96, 0.85, 0.32 and 1.0, 1.0, 1.1, 0.41, 0.52, separately. There was a significant DNA damage with a dose-effect relationship in all study groups (F = 41.22, P < 0.05), and the comet Olive tail moment was (2.98 ± 1.43), (4.76 ± 1.79), (10.09 ± 1.75), (11.38 ± 1.77), (11.67 ± 1.88). The further study found that the index of DNA damage was negatively correlated to the expression of MGMT mRNA and its protein.

CONCLUSIONThe DNA damage induced by COE might be associated with the suppression of MGMT caused by its hypermethylation.

Bronchi ; cytology ; Cell Line ; Coke ; adverse effects ; Comet Assay ; DNA Damage ; DNA Methylation ; DNA Repair ; Epithelial Cells ; metabolism ; Gene Silencing ; Humans ; O(6)-Methylguanine-DNA Methyltransferase ; genetics ; metabolism