High altitude hypoxia aggravates chronic inflammation induced by LPS in rats / 军事医学

Objective To investigate the effect of high altitude hypoxia on chronic inflammation in rats.Methods Forty SD rats were randomly divided into 4 groups: control group (Con),chronic inflammation group (CI),high altitude hypoxia group (HH),high altitude hypoxia+chronic inflammation group (HH+CI).Rats in CI group were injected with lipopolysaccharide (LPS) (0.5 mg/kg) through the caudal vein twice a week for 4 weeks.Rats in HH+CI group were treated just as CI group was,but together with HH group rats were settled in a hypoxic environment of 6000 m altitude for three days.Pathological changes in lung tissues were observed by hematoxylin eosin stain.The peripheral white blood cell count and classification were measured.The levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in serum and lung tissues were detected by enzyme-linked immunosorbent assay (ELISA).Changes in IL-6 expression in rat lung tissues were observed by Western blotting.Results After LPS and high altitude hypoxia exposure,inflammatory cells infiltration and alveolar capillary expansion were observed in rats' lung tissue.Compared with Con group,not only the peripheral white blood cell count,but also the level of IL-6 and TNF-α in serum and lung tissue increased in CI and HH group(P<0.01).IL-6 expression levels observed by Western blotting were also increased in HH and CI group(P<0.01).High altitude hypoxia and chronic inflammation interacted(P<0.01).The peripheral white blood cell count was higher in HH+CI group than in other groups,and IL-6 and TNF-α expressions in lung tissue were increased(P<0.05).Conclusion An LPS-induced chronic inflammation model in rats is successfully obtained,and high altitude hypoxia could aggravate chronic inflammation.

The protective effect of rosiglitazone on the rats with high altitude pulmonary edema / 中华急诊医学杂志

Objective To investigate the protective effect of rosiglitazone on the rats with high altitude pulmonary edema.Methods Thirty-six SD rats were randomly (random number) divided into 6 groups (n =6 each):control group (Control),hypobaric hypoxia model group (HH),rosiglitazone groups (RSG) which were administered with 3 different doses [RSG-L:5 mg/ (kg · d),RSG-M:10 mg/ (kg·d),RSG-H:20 mg/ (kg· d)],dexamethasone group [Dex,4 mg/ (kg· d)].Rats were injected intraperitoneally with different doses of rosiglitazone (RSG),dexamethasone (Dex) or vehicle (Control and HH) for 3 days before placed in simulated altitude of 6 000 m hypobaric hypoxia animal chamber where the temperature and pressure were constant.After 72 h in the chamber,each rat was anesthetized.The water content of lung was determined with wet/dry weight ratio.Bronchoalveolar lavage fluid was measured by bradford method.The contents of GSH was measured by micro-ezymed labeled method.The contents of MDA was measured by TBA method.The enzymatic activities of SOD was measured by WST-1 method.The changes of the TNF-α,IL-6 and IL-10 in serum were determined by ELISA.Light microscope was used to observe the pathological changes of lung tissue.Results Compared with Control group,the wet/dry weight ratio of lung (5.08 ± 0.24) and total protein content of BALF (351.06 ± 44.55) μg/mL increased significantly (P ＜ 0.01) in HH group.There were red blood cells in the alveolar and interstitium,pink fluid exudation in the alveolar,the alveolar septum enhancement,and a large number of inflammatory cell infiltration;the SOD activity (10.65 ± 0.94) U/mgprot and the content of GSH (1.63 ±0.20) μmol/gprot in lung tissue were significantly decreased (P ＜ 0.01),the contents of MDA (2.1 5 ± 0.18) nmol/mgprot increased significantly (P ＜ 0.01),TNF-o (56.92 ± 2.87) pg/mL and IL-6 (217.80 ±48.01) pg/mL levels in serum were significantly increased (P ＜0.01),and IL-10 (76.85 ± 16.72) pg/mL level decreased (P ＜ 0.05).Compared with the HH group,the wet/dry ratio of lung and total protein content of BALF in different doses of rosiglitazone group significantly decreased (P ＜ 0.01),the pathological changes of the lung tissue was significantly improved,SOD activity and the content of GSH in lung tissue was significantly increased (P ＜ 0.01),the content of MDA decreased (P ＜ 0.01),The levels of TNF-α and IL-6 in serum were significantly decreased (P ＜ 0.01),while the IL-10 level was significantly increased (P ＜ 0.01).Conclusion Rosiglitazone could protect the high altitude pulmonary edema by alleviating the oxidative stress and inflammatory response.

Optimization of prokaryotic expression condition and purification of soluble GST-CRH protein / 天津医药

Objective To obtain the recombinant corticotropin releasing hormone (CRH) protein with soluble, high purity protein through optimizing prokaryotic expression condition and purifying glutathione thiol transferase (GST)-CRH protein. Methods To detect the expression of soluble CRH protein through grope of the host strain GST-CRH temperature of induction expression, the host strain concentration (OD600), IPTG concentration and induction time, the purification of GST-CRH was performed by GST-CRH agarose gel. Western Blot assay was used for the expression identification of the target protein. Results The optimal conditions for the induction of CRH protein were determined: temperature of 30 ℃, IPTG induced concentration 0.1 mmol/L, bacteria density (OD600) 0.8, the induction time of 8 hours, purified GST-CRH>95% fusion protein was obtained. Conclusion The optimal expression conditions of GST-CRH are obtained, and the soluble protein of high purity GST-CRH is also obtained.

Oxidative damage and related signal pathways caused by lipopolysaccharide induced sepsis in rat brain / 军事医学

Objective To investigate the mechanism of oxidative damage caused by lipopolysaccharide (LPS)induced sepsis in rat brain.Methods The rats were randomly divided into control group and model group (low LPS group and high LPS group).Twenty-four hours after the modeling,the rats were sacrificed before their brain tissue was taken out and prepared for the test.The changes in malondialdehyde (MDA),superoxide dismutase (SOD),glutathione peroxidase (GSH-Px),total antioxidant capacity (T-AOC),hydrogen peroxide (H2 O2 )and succinate dehydrogenase (SDH)were detected.The expression level of JNK and Nrf2 protein in brain tissue was detected by qRT-PCR and Western blotting. Results Compared with the control group,the MDA,SOD,GSH-px,T-AOC,H2O2 and SDH level increased significantly in the model group,and the difference in expressions of JNK and Nrf2 was statistically significant (P <0.05). Conclusion The LPS induced septic oxidative brain damage model in rats is successfully established,and the process may be regulated through the Nrf2 and JNK signal pathways.

Preparation of anti-TLR4 extracellular C-terminal domain monoclonal antibody and its application to sepsis / 中华创伤杂志

Objective To prepare the anti-TLR4 C-terminal domain monoclonal antibody and investigate its effect in treatment of sepsis.Methods TLR4 C-terminal polypeptide (amino acid sequence:368-579,named as TLR4-C) was obtained through prokaryotic expression and Sephacryl S-100 gel purification,and then was used to immunize female Balb/c mice (6-8 weeks old).After cell fusion,antibody screening and purification,monoclonal antibody specific for the C terminal of TLR4 was obtained.Specificity of monoclonal antibody was detected by Western blot and cell immunofluorescence.In vitro antibody activity test,NR8383 was cultured for 1 h with adding antibody (100 μg/ml) and then 12 h after adding lipopolysaccharide (LPS) (10 ng/ml),and level of tumor growth factor (TNF)-α in the culture medium was tested by ELISA.In vivo septic animal experiment,40 SD rats were assigned to control antibody group (n =20) and anti-TLR4 monoclonal antibody group (n =20) according to the random number table.Each group was rejected 50 mg/kg corresponding antibodies via caudal vein for 1 h,and then LPS (10 mg/kg) via intraperitoneal injection for 4 h.Blood samples from caudal vein of ten rats in each group were collect to test the serum level of TNF-α.The rest rats in each group were used to measure the animal survival rate within 72 h.Results Three highly specific anti-TLR4 monoclonal antibodies were obtained and could combined with TLR4-C and TLR4 holoprotein.In vitro cell activity study indicated only one monoclonal antibody could obviously inhibit the release of TNF-α.In vivo animal experiment showed serum TNF-α level in anti-TLR4-C antibody group was (1.54 ± 0.18) ng/ml,significantly lower than (0.51 ± 0.10) ng/ml in antibody control group (P ＜ 0.01).Animal survival rate in anti-TLR4-C antibody group was 70％,higher than 30％ in antibody control group (P ＜ 0.05).Conclusion Anti-TLR4-C monoclonal antibodies have great capacity to neutralize TLR4 and good protective effect on LPS-induced sepsis.

A clinical study of neuromuscular electrical stimulation on patients with dysphagia after stroke / 中华物理医学与康复杂志

Objective To investigate the types of dysphagia after stroke (DAS) calling for neuromuscular electrical stimulation (NMES) and to explore the probable mechanisms of the treatment. Methods Sixty patients with DAS diagnosed by videofluoroscopie swallowing study (VFSS) were enrolled in this study. They were randomly divided into a treatment group (n = 30) and a control group (n = 30). VFSS, misaspiration, laryngeal elevation, food residues and food intake scores of the two groups were evaluated and compared before and after 10 days of treat-ment. After that, both groups were divided into mild, moderate and severe sub-groups separately according to their VFSS scores. The VFSS scores of the six subgroups were then compared. Results There was no significant differ-ence between the two groups with regard to VFSS scores and misaspiration, laryngeal elevation, food residues, food intake scores before treatment. After 10 days of treatment, VFSS scores in the treatment group were significantly high-er than in the control group, and miaspiration and laryngeal elevation scores were significantly lower. There were no significant difference between the two groups in terms of food residues and food intake scores. The VFSS scores of pa-tients with moderate DAS in the treatment group were significantly higher than those in the control group, but there was no significant difference between patients with mild and moderate DAS in the two groups. Conclusions NMES could be an effective treatment for DAS. NMES treatment is most effective for moderate DAS, but has no advantage in treating the mild cases. NMES may improve laryngeal elevation and decrease misaspiration.