Objective:To investigate the changes in sympathetic nerve activity after lower limb immobilization and the role of sympathetic nerve in regulating disuse atrophy of skeletal muscles.Methods:The experiment was divided into the following 3 parts: ① Twelve 8-week-old male C57 mice were randomly divided into a blank control group and a hind limb fixation group ( n=6). The blank control group received no intervention while the hind limb fixation group received splint fixation of the hind limbs for 2 weeks before the musculoskeletal multi-dimensional characterization was completed at the behavioral, pathological and molecular levels. ② Thirty-six 8-week-old male C57 mice were selected and randomly divided into a control group and 5 hind limb fixation groups (for 1, 3, 5, 7 and 14 days) ( n=6). The control group was fed normally until 14 days without any intervention while the 5 hind limb fixation groups were sampled after fixation for 1, 3, 5, 7 and 14 days, respectively. The level of norepinephrine in the serum and the expression level of tyrosine hydroxylase (TH), a marker of sympathetic nerve activity in the paraventricular nucleus of hypothalamus (PVN), were detected to observe the plasticity of sympathetic nerve activity. ③ Eighteen 8-week-old male C57 mice were selected and randomly divided into a blank control group, a hind limb fixation group and a hind limb fixation plus medication group ( n=6). The blank control group received no intervention while the 2 fixation groups were injected with phosphate buffer (PBS) and propranolol hydrochloride solution for 2 consecutive weeks, respectively. The parameters related to the skeletal muscles were compared between the 3 groups. Results:① Compared with the control group, the mass and function of skeletal muscles in the hind limb fixation group were statistically significantly decreased ( P<0.05). ② The levels of serum norepinephrine [(3.27±1.03) ng/mL, (9.21±1.05) ng/mL, (6.36±0.88) ng/mL, (3.84±1.00) ng/mL, and (3.91±0.75) ng/mL] and the PVN TH levels (42.00%±5.38%, 61.67%±5.57%, 55.82%±3.11%, 50.90%±2.53%, and 39.17%±9.07%) in the 5 hind limb fixation groups (for 1, 3, 5, 7 and 14 days) were significantly higher than those in the control group [(1.81±0.72)] ng/mL and 23.33%±5.50%] ( P<0.05). ③ The wet weight of the gastrocnemius muscle [(93.50±4.32) mg] and the cross-section area of the tibial anterior muscle [(1,180.00±95.09) μm 2] in the hind limb fixation plus medication group were increased significantly compared with those in the hind limb fixation group [(80.83±9.99) mg and (907.80±121.00) μm 2] ( P<0.05). Conclusions:Overactivation of the sympathetic nervous system occurs in the mice model of skeletal muscle disuse atrophy after hind limb fixation. Inhibition of sympathetic nerve activity may reduce the severity of skeletal muscle atrophy at the lower limbs.

Objective:To investigate the changes in sympathetic nerve activity after lower limb immobilization and the role of sympathetic nerve in regulating disuse atrophy of skeletal muscles.Methods:The experiment was divided into the following 3 parts: ① Twelve 8-week-old male C57 mice were randomly divided into a blank control group and a hind limb fixation group ( n=6). The blank control group received no intervention while the hind limb fixation group received splint fixation of the hind limbs for 2 weeks before the musculoskeletal multi-dimensional characterization was completed at the behavioral, pathological and molecular levels. ② Thirty-six 8-week-old male C57 mice were selected and randomly divided into a control group and 5 hind limb fixation groups (for 1, 3, 5, 7 and 14 days) ( n=6). The control group was fed normally until 14 days without any intervention while the 5 hind limb fixation groups were sampled after fixation for 1, 3, 5, 7 and 14 days, respectively. The level of norepinephrine in the serum and the expression level of tyrosine hydroxylase (TH), a marker of sympathetic nerve activity in the paraventricular nucleus of hypothalamus (PVN), were detected to observe the plasticity of sympathetic nerve activity. ③ Eighteen 8-week-old male C57 mice were selected and randomly divided into a blank control group, a hind limb fixation group and a hind limb fixation plus medication group ( n=6). The blank control group received no intervention while the 2 fixation groups were injected with phosphate buffer (PBS) and propranolol hydrochloride solution for 2 consecutive weeks, respectively. The parameters related to the skeletal muscles were compared between the 3 groups. Results:① Compared with the control group, the mass and function of skeletal muscles in the hind limb fixation group were statistically significantly decreased ( P<0.05). ② The levels of serum norepinephrine [(3.27±1.03) ng/mL, (9.21±1.05) ng/mL, (6.36±0.88) ng/mL, (3.84±1.00) ng/mL, and (3.91±0.75) ng/mL] and the PVN TH levels (42.00%±5.38%, 61.67%±5.57%, 55.82%±3.11%, 50.90%±2.53%, and 39.17%±9.07%) in the 5 hind limb fixation groups (for 1, 3, 5, 7 and 14 days) were significantly higher than those in the control group [(1.81±0.72)] ng/mL and 23.33%±5.50%] ( P<0.05). ③ The wet weight of the gastrocnemius muscle [(93.50±4.32) mg] and the cross-section area of the tibial anterior muscle [(1,180.00±95.09) μm 2] in the hind limb fixation plus medication group were increased significantly compared with those in the hind limb fixation group [(80.83±9.99) mg and (907.80±121.00) μm 2] ( P<0.05). Conclusions:Overactivation of the sympathetic nervous system occurs in the mice model of skeletal muscle disuse atrophy after hind limb fixation. Inhibition of sympathetic nerve activity may reduce the severity of skeletal muscle atrophy at the lower limbs.

Objective To explore response element that maintains basic transcriptional activity of intestinal trefoil factor (ITF) promoter.Methods Truncated and mutant 5' flanking sequences of ITF gene were cloned from ITF promoter sequences by PCR,and then they were inserted into the pGL3-basic vector to construct truncated and mutant luciferase vectors to conduct the following experiments.(1) Human embryonic kidney 293 (HEK293) cells were divided into pGL3-basic group,pGL3-300 group,pGL3-280 group,pGL3-260 group,pGL3-240 group,pGL3-220 group,and pGL3-200 group according to the random number table (the same grouping method below),with 3 wells in each group,and they were respectively transfected with 500 ng corresponding plasmids and 15 ng renilla luciferase reporter plasmids pRL-TK.After being cultured for 48 hours,the relative luciferase activity of cells was measured by single tube detection system.(2) Another batch of HEK293 cells were divided into pGL3-basic group,pGL3-300 group,mutant 1,2,3,and 4 groups,with 3 wells in each group,and they were respectively transfected with 500 ng pGL3-basic,pGL3-300,mutant 1,2,3,and 4 plasmids and 15 ng pRL-TK plasmids.After being cultured for 48 hours,the relative luciferase activity of cells was measured as in (1).(3) Another batch of HEK293 cells were divided into blank control group and 10,50 μmol/L mithramycin groups,with 3 wells in each group.After being transfected with 500 ng pGL3-300 plasmids and 15 ng pRL-TK plasmids,cells in blank control group were not transfected with mithramycin,while cells in the latter two groups were respectively transfected with 10 and 50 μmol/L mithramycin.After being cultured for 24 hours,the relative luciferase activity of cells was measured as in (1).(4) Another batch of HEK293 cells were divided into blank control group and 0.1,0.2,and 0.3 μg pcDNA3,1-Sp1 groups,with 3 wells in each group.After being transfected with 500 ng pGL3-300 plasmids and 15 ng pRL-TK plasmids,cells in blank control group were not transfected with pcDNA3.1-Spl plasmids,while cells in the latter three groups were respectively transfected with 0.1,0.2,and 0.3 μg pcDNA3.1-Sp1 plasmids.After being cultured for 48 hours,the relative luciferase activity of cells was measured as in (1).Data were processed with one-way analysis of variance and LSD test.Results (1) The relative luciferase activity of cells in pGL3-basic group,pGL3-300 group,pGL3-280 group,pGL3-260 group,pGL3-240 group,pGL3-220 group,and pGL3-200 group was 1.00,7.99 ±0.51,2.03 ±0.55,2.50 ±0.40,2.50 ±0.15,1.72 ±0.19 and 2.10 ± 0.21,respectively.The relative luciferase activity of cells in pGL3-280 group,pGL3-260 group,pGL3-240 group,pGL3-220 group,and pGL3-200 group was significantly lower than that in pGL3-300 group (with P values below 0.01).(2) The relative luciferase activity of cells in pGL3-basic group,pGL3-300 group,mutant 1,2,3,and 4 groups was 1.00,7.99 ±0.51,2.10 ±0.56,7.03 ± 1.05,5.09 ± 1.40 and 8.15 ± 1.48,respectively.The relative luciferase activity of cells in mutant 1 group was significantly lower than that in pGL3-300 group (P ＜ 0.01).The relative luciferase activity of cells in pGL3-300 group,mutant 2,3,and 4 groups was similar (with P values above 0.05).(3) The relative luciferase activity of cells in 10 and 50 μmol/L mithramycin groups was respectively 3.07 ± 0.60 and 2.93 ± 0.55,which was significantly lower than that in blank control group (8.05 ± 0.83,with P values below 0.01).(4) The relative luciferase activity of cells in 0.1,0.2,and 0.3 μg pcDNA3.1-Sp1 groups was respectively 12.74 ± 1.12,14.52 ± 1.25,and 15.66 ± 1.82,which was significantly higher than that in blank control group (8.13 ± 0.71,with P values below 0.05).Conclusions One Sp1 binding site,locating in the region from-301 to-293 bp of ITF promoter,is the core element for regulating the basic transcriptional activity of ITF.

OBJECTIVE Through detecting to drug susceptibility results of 12 commonly used antibiotics in Pseudomonas aeruginosa (PAE),we provide the scientific basis for the prevention of infection and reasonable choice of antibiotics. METHODS Twelve antibiotics′ susceptibility tests in vitro were carried out in PAE isolated from lower respiratory tract in Renming Hospital,Wuhan University from Jan 2007 to Dec 2008. RESULTS In the anti-infective drugs,the resistance rate to ceftazidime was the lowest (36.8%),followed by amikacin (39.6%),piperacillin/tazobactam (43.8%),cefepime (47.8%) and cefoperazone/sulbactam (48.5%).The resistant status of PAE was serious and multi-drug resistance existed. CONCLUSIONS The lower respiratory tract infection caused by PAE which possesses single and multiple drug-resistance. We should more think of it and strengthen preventive measures to reduce the rate of infection. Reasonably prudent use of antibiotics is still the best way of delaying its rapid increase of drug-resistance strains.

OBJECTIVE To investigate antibiotic resistance in nosocomial infections with Acinetobacter baumannii from lower respiratory tract in the intensive care unit(ICU) and guide clinically rational use of drug.METHODS Antibiotics susceptibility tests in 109 clinical isolates of A.baumannii from lower respiratiory tract were performed by K-B disk diffusion method.The results were judged according to CLSI 2007.As controls,standard strain was used simultaneously.RESULTS The sensitivity rate to cefoperazone/sulbactam was the highest,arriving at 77.1% and followed by imipenem(57.8%) and meropenem(54.9%).The other antibiotics were below 50.0%,generally.The serious cross-resistance phenomenon was in present.Pan-resistant strains had been detected.CONCLUSIONS The drug-resistant status in nosocomial infections with A.baumannii from lower respiratory tract in ICU is very serious.We should continue to strengthen the monitoring of the antibiotic resistance and prevent the outbreak epidemics of drug resistant strains in ICU.