Objective To evaluate the effect of mechanical stretch preconditioning on pathological stretch-induced activation of γ-aminobutyric acid (GABA) signaling pathway in human type Ⅱ alveolar epithelial cells (AEC Ⅱ).Methods AEC Ⅱ cell line (A549 cells) culturedin vitro were divided into control group (group C), pathological stretch group (group P1) and mechanical stretch preconditioning group (group P2). In group C, A549 cells were cultured routinely. In group P1, A549 cells were exposed to 20% cyclic stretch for 6 hours. In group P2, A549 cells were exposed to 5% cyclic stretch for 60 minutes, and then exposed to 20% cyclic stretch for 6 hours. The cells were harvested for determination of the cell viability by methyl thiazolyl tetrazolium assay, lactate dehydrogeuase (LDH) release was determined by colorimetric method, the levels of interleukin (IL-1β and IL-6) and tumor necrosis factor-α (TNF-α) were determined by enzyme linked immunosorbent assay (ELISA), the mRNA expressions of IL-1β, IL-6 and TNF-α were determined by reverse transcription-polymerase chain reaction (RT-PCR), and the protein expressions of glutamic acid decarboxylase (GAD) and γ-aminobutyric acid A receptor (GABAAR) were determined by Western Blot.Results Compared with group C, the cell viability of group P1 was significantlydecreased (A value: 0.196± 0.071 vs. 0.886±0.107), the release rate of LDH was significantly increased [(12.3±2.4)% vs. (1.9±0.5)%]; the contents and mRNA expressions of IL-1β, IL-6 and TNF-α in cell culture medium were significantly increased [IL-1β (ng/L): 138.6±19.7 vs. 32.7±7.4, IL-6 (ng/L): 196.5±31.7 vs. 55.4±13.8, TNF-α (ng/L): 111.3±21.8 vs. 20.8±7.6; IL-1β mRNA (2-ΔΔCT): 2.79±0.44 vs. 0.83±0.12, IL-6 mRNA (2-ΔΔCT): 1.99±0.25 vs. 0.56±0.11, TNF-α mRNA (2-ΔΔCT): 2.54±0.37 vs. 0.72±0.09]; the protein expressions of GAD and GABAAR were significantly decreased [GAD (gray value): 0.38±0.12 vs. 1.75±0.45, GABAAR (gray value): 0.29±0.09 vs. 1.68±0.39; allP < 0.05]. Compared with group P1, the cell viability of group P2 was significantly increased (A value: 0.523±0.132 vs. 0.196±0.071),the release rate of LDH was significantly decreased [(6.9±1.7)% vs. (12.3±2.4)%]; the contents and mRNA expressions of IL-1β, IL-6 and TNF-α in cell culture medium were significantly decreased [IL-1β (ng/L): 79.2±11.6 vs. 138.6±19.7, IL-6 (ng/L): 89.6±15.6 vs. 196.5±31.7, TNF-α (ng/L): 55.9±11.4 vs. 111.3±21.8; IL-1β mRNA (2-ΔΔCT): 1.92±0.36 vs. 2.79±0.44, IL-6 mRNA (2-ΔΔCT): 1.09±0.18 vs. 1.99±0.25, TNF-α mRNA (2-ΔΔCT): 1.77±0.25 vs. 2.54±0.37]; the protein expressions of GAD and GABAAR were significantly increased [GAD (gray value): 1.26±0.33 vs. 0.38±0.12, GABAAR (gray value): 1.04±0.15 vs. 0.29±0.09; allP < 0.05]. Conclusion The mechanism by which mechanical stretch preconditioning attenuates pathological stretch-induced injury in human AECⅡ is related to the activation of GABA signaling pathway.

Objective To evaluate plasma natriuretic peptide brain (BNP) levels in elderly male patients with type 2 diabetes and primary osteoporosis.Methods A total of 122 elderly male patients with type 2 diabetes were divided into 3 groups according to bone mineral density(BMD):normal group (41 cases),osteopenia group (40 cases) and osteoporosis group (41 cases),and another 33 age matched healthy subjects as control group.Plasma BNP levels were determined by ELISA.Results Plasma BNP levels in osteoporosis group [(1.95 ± 0.49) pmol/L] and osteopenia group [(1.64±0.48) pmol/L] were significantly elevated compared with that in normal group [(1.32±0.38) pmol/L] and control group [(1.26±0.39) pmol/L] (all P＜0.01).There was a statistical difference between osteoporosis group and osteopenia group (t=3.539,P＜0.05),and also between normal group and control group (t=2.726,P＜0.05).Plasma BNP levels had negative correlation with BMD of 2na-4th lumbar vertebra (r=-0.366) and femoral neck (r=-0.375),body mass index (r=-0.288) and estrodiol (E2) (r=-0.352) (all P＜0.05); while had a positive correlation with parathyroid hormone (PTH) (r=0.353,P＜0.05).Conclusions With BMD declining,plasma BNP levels are elevated in elderly male type 2 diabetes,which may be related to the compensatory increase in PTH and the decrease in estradiol.

Objective To evaluate the effect of dexmedetomidine on janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway in mice with endotoxin-induced acute lung injury (ALI).Methods Twenty-four male C57BL/6 mice,weighing 20-25 g,were randomly divided into 3 groups (n=8 each) using a random number table:control group (group C),endotoxin-induced ALI group (group ALI),and dexmedetomidine group (group Dex).ALI was induced with lipopolysaccharide (LPS) 5 mg/kg injected intraperitoneally.Dexmedetomidine 40 μg/kg was injected intraperitoneally at 1 h after LPS injection in group Dex,while the equal volume of normal saline was given in C and ALI groups.At 6 h after LPS injection,blood samples were collected from the carotid artery to detect arterial oxygen partial pressure (PaO2).The mice were then sacrificed,and broncho-alveolar lavage fluid (BALF) was collected for determination of the concentrations of total protein,interleukin-1β (IL-1β),IL-6 and tumor necrosis factor-or (TNF-α).The lung tissues were removed for determination of wet to dry lung weight ratio (W/D ratio),and expression of phosphorylated JAK2 (p-JAK2),phosphorylated STAT3 (p-STAT3),IL-1β mRNA,IL-6 mRNA and TNF-α mRNA,and for examination of the pathological changes which were scored.Results Compared with group C,the PaO2 was significantly decreased,and W/D ratio,lung injury score,concentrations of total protein,IL-1β,IL-6 and TNF-α in BALF,and expression of IL-1β,IL-6 and TNF-α mRNA,p-JAK2 and p-STAT3 were increased in ALI and Dex groups (P＜0.05).Compared with group ALI,the PaO2 was significantly increased,and W/D ratio,lung injury score,concentrations of total protein,IL-1β,IL-6 and TNF-α in BALF,and expression of IL-1β,IL-6 and TNF-α mRNA,p-JAK2 and p-STAT3 were decreased in group Dex (P＜0.05).Conclusion The mechanism by which dexmedetomidine attenuates LPS-induced ALI is probably related to inhibition of activation of JAK2/STAT3 signaling pathway in mice.

Objective To evaluate the effect of goal-directed fluid therapy (GDFT) on postoperative cognitive function in the patients undergoing intracranial tumor resection.Methods One hundred patients of both sexes,aged 45-64 yr,weighing 50-70 kg,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,scheduled for elective cerebral glioma or meningioma resection,were randomly divided into 2 groups (n=50 each) using a random number table:GDFT group (group G) and conventional fluid therapy group (group C).The mean arterial pressure was maintained at 65-110 mmHg,urine volume ＞0.5 ml · kg-1 · h-1,and central venous pressure at 8-12 cmH2O in group C.In group G,GDFT was performed using FloTrac/Vigileo system,and the cardiac index was maintained at 2.5-4.0 L · min-1 · n 2,stroke volume variation≤ 13％,mean arterial pressure at 65-110 mmHg,and stroke volume index at 35-47 ml/m2.The requirement for crystalloid and colloid,urine volume,blood loss,and requirement for vasoactive agents were recorded during operation.Before induction of anesthesia (baseline),when the dura of brain was opened,at the end of tumor removal,at the end of operation,and at 24 h after operation (T0-4),venous blood samples were taken to determine the concentrations of serum neuron-specific enolase (NSE) and S100β protein by enzyme-linked immunosorbent assay.The patient's cognitive function was assessed using Mini-Mental State Examination at T0 and 7 days after operation (T5).Results Compared with the baseline value at T0,the serum NSE and S100β protein concentrations were significantly increased at T24 in the two groups (P＜0.05).Compared with group C,the requirement for colloid,total volume of fluid infused and urine volume during operation were significantly increased,the serum NSE and S100β protein concentrations were significantly decreased at T3,4 (P＜0.05),and no significant change was found in Mini-Mental State Examination score at T0 and T5 in group G (P＞0.05).Conclusion GDFT based on FloTrac/Vililgeo system can reduce the damage to brains after operation,but it has no significant effect on postoperative cognitive function in the patients undergoing intracranial tumor resection.

Objective To evaluate the effects of mechanical stretch preconditioning on pathological stretch-induced activation of nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) signaling pathways in human type Ⅱ alveolar epithelial cells.Methods Human type Ⅱ alveolar epithelial cell line A549 cells cultured in vitro were randomly divided into 3 groups (n =24 each) using a random number table: control group (group Ⅰ), pathological stretch group (group Ⅱ), and mechanical stretch preconditioning group (group Ⅲ).In group Ⅰ , A549 cells were cultured routinely without receiving pathological stretch.In group Ⅱ , A549 cells were exposed to 20％ cyclic stretch at 0.3 Hz for 6 h.In group Ⅲ , A549 cells were exposed to 5％ cyclic stretch at 0.3 Hz for 60 min, and then exposed to 20％ cyclic stretch at 0.3 Hz for 6 h.After the end of the treatment, the cells were collected for determination of the cell viability (by methyl thiazolyl tetrazolium assay) and lactate dehydrogeuase (LDH)release (by colorimetric method).The concentrations of tumor necrosis factor-alpha (TNF-α),interleukin-8 (IL-8) and high mobility group box 1 (HMGB1) in the culture medium were detected using enzyme linked immunosorbent assay.The expression of total NF-κB, phosphorylated NF-κB, total STAT3 and phosphorylated STAT3 was detected using Western blot.The ratios of phosphorylated NF-κB to total NF-κB and phosphorylated STAT3 to total STAT3 were calculated to reflect the activation.Results Compared with group Ⅰ , the cell viability was significantly decreased, the amount of LDH released was increased, and the concentrations of TNF-α, IL-8 and HMGB1, and activation of NF-κB and STAT3 were increased in Ⅱ and Ⅲ groups.Compared with group Ⅱ , the cell viability was significantly increased, the amount of LDH released was decreased, and the concentrations of TNF-α, IL-8 and HMGB1, and activation of NF-κB and STAT3 were decreased in group Ⅲ.Conclusion The mechanism by which mechanical stretch preconditioning attenuates pathological stretch-induced damage to human type Ⅱ alveolar epithelial cells is related to inhibited activation of NF-κB and STAT3 signaling pathways.

Objective To evaluate the effect of ulinastatin on γ-aminobutyric acid (GABA) signal pathway in mice with ventilator-induced lung injury (VILI).Methods Thirty-six male Wister mice were randomly divided into 3 groups using a random number table:control group (group C), ventilator-induced lung injury group (group VILI),and ventilator-induced lung injury+ ulinastatin group (group UTI),n =12 in each group.VILI was induced by 4 h mechanical ventilation with tidal volume 40 ml/kg in groups VILI and UTI.Ulinastatin 1×10 5 U/kg was injected intraperitoneally 1 h before ventilation in group UTI,while the equal volume of normal saline was given in groups C and VILI.The mice were then sacrificed,the left lung was lavaged,and broncho-alveolar lavage fluid (BALF)was collected for determination of concentrations of protein,tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and intercellular adhesion molecule-1 (ICAM-1).The lung tissues were re-moved for determination of the wet to dry lung weight (W/D)ratio,the mRNA expression level of IL-1β,TNF-αand ICAM-1.The pathological changes of the lungs were determined under light micro-scope and the lung injury scores were also determined.Immunohistochemistry and Western blot were used to detected the protein expression level of GAD and GABAA R.Results The W/D ratio (6.7 ± 2.4 vs.8.5±2.3)and lung scores [(6.9±2.3)scores vs.(1 1.8±2.7)scores]were significantly de-creased in group UTI than those in group VILI.The concentrations of IL-1β[(56±1 1)ng/L vs.(77 ±1 5)ng/L],TNF-α[(105±29)ng/L vs.(1 58±37)ng/L]and ICAM-1 [(205±46)ng/L vs.(293 ±61)ng/L]in BALF in group UTI were significantly decreased than those in group VILI.The mRNA ex-pression levels of IL-1β(1.81±0.26 vs.2.58±0.34),TNF-α(1.61±0.15 vs.2.94±0.27)and ICAM-1 (1.74±0.27 vs.2.79±0.31)were significantly decreased in group UTI than those in group VILI.The protein expression levels of GAD (0.44±0.08 vs.0.18 ±0.04)and GABAA R (0.30 ±0.09 vs.0.15 ± 0.04)were significantly increased in group UTI than those in group VILI.Conclusion Ulinastatin can at-tenuate VILI probably through activating GABA signaling pathway.

Objective To evaluate the effect of lung protective ventilation strategy on inflammatory responses in brain tissues of elderly patients requiring one-lung ventilation (OLV) during radical resection for esophagus cancer.Methods Sixty patients of both sexes,aged 65-80 yr,weighing 45-75 kg,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,scheduled for elective radical resection for esophageal cancer,were divided into volume-controlled ventilation (VCV) group (n =30) and VCV plus protective ventilation strategy group (PV group,n =30) using a random number table.In group VCV,the tidal volume was set at 10 ml/kg during two-lung ventilation (TLV) and at 7 ml/kg during OLV with inspiratory/expiratory ratio 1:2.In group PV,the tidal volume was set at 7 ml/kg during TLV and at 5 ml/kg during OLV with inspiratory/expiratory ratio 1:2 and positive end-expiratory pressure 5 cmH2O,and lung recruitment maneuver was performed every 45 min.End-tidal pressure of carbon dioxide was maintained at 35-45 mmHg,and bispectral index value at 40-60 in both groups.Before induction of anesthesia (T1),at 10 min of TLV (T2),at 30 min of OLV (T3),at 15 min after restoration of TLV (T4) and at 24 h after operation (T5),jugular bulb venous blood samples were taken for determination of serum glial fibrillary acid protein,tumor necrosis factor-α and interleukin-6 concentrations by enzyme-linked immunosorbent assay.The cognitive function was assessed using Mini-Mental State Examination before operation (T0),at T5 and at 3 and 7 days after operation (T6,7).The occurrence of postoperative delirium was recorded.Results Compared with group VCV,the serum concentrations of tumor necrosis factor-α,interleukin-6 and glial fibrillary acid protein were significantly decreased at T3-5,Mini-Mental State Examination scores were increased at T6,7,and the incidence of postoperative delirium was decreased in group PV (P＜0.05).Conclusion The mechanism by which lung protective ventilation strategy decreases the development of postoperative cerebral dysfunction is related to reduction of inflammatory responses in brain tissues of elderly patients requiring OLV during radical resection for esophagus cancer.

Objective To investigate the relationship of plasma fibrinogen (FIB) and non-highdensity lipoprotein cholesterol (non-HDL-C) with diabetic nephropathy in the elderly with type 2 diabetes. Methods Totally 152 patients (aged 60 years and over) with type 2 diabetics were divided into normal albuminuria (UAER＜30 mg/24 h,n=89) and abnormal albuminuria (UAER≥ 30 mg/24 h,n=63) groups,with high FIB (＞4.00 g/L,n=88) and normal FTB (2.00-4.00 g/L,n=64)sub-groups.The body mass index (BMI),systolic blood pressure (SBP),diastolic blood pressure (DBP),fasting plasma glucose (FPG),postprandial blood glucose (2 hPG),glycated hemoglobin (HbAlc),serum triglyceride (TG),total cholesterol (TC),high density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol (LDL-C),FIB and 24-hour urinary albumin excretion rate (UAER) were measured.The non-HDL-C and estimated glomerular filtration rate (eGFR) were calculated. Results Compared with normal albuminuria group,the values of age,hypertension rate,SBP,Scr and FIB in abnormal albuminuria group were increased [(74.6 ± 7.3) years,57 cases (90.5％),(146.8±23.2)mm Hg,(1.010.7)μmol/L,(4.8±1.5)g/Lvs.(71.6±7.2)years,59 cases (66.3％),(137.7±19.2) mm Hg,(0.8±0.3)μmol/L,(4.2±1.3)g/L,t=-2.536,-2.656,- 2.474,-2.857,x2 =11.936,all P＜0.05] while eGFR was significantly decreased [(68.5±31.2)ml · min-1 · 1.73 m-2 vs.(81.4±25.9)ml · min-1 · 1.73m-2,t=2.791,P＜0.05].The number of patients with high FIB was enhanced in abnormal albuminuria group than normal albuminuria group[45 cases (71.4％) vs. 18 cases (28.6％),x2 =8.085,P=0.004]. The proportion of abnormal albuminuria in high FIB group was lower than that in normal FIB group [(62.6±30.5) ml· min-1 · 1.73 m-2 vs.(83.2±28.7) ml· min-1 · 1.73 m 2,t=2.459,P=0.017].The Pearson analysis revealed that UAER was positively correlated with FIB,TG,TC and non-HDL-C (r=0.276,0.268,0.243,0.176,all P＜0.05).Stepwise regressive analysis showed that FIB was an independent risk factors of urinary albumin in the elderly with type 2 diabetes.Conclusions Higher levels of FIB and non-HDL-C are well correlated with diabetic nephropathy in the elderly with type 2 diabetes.

Objective To evaluate the effects of lung-protective ventilation on the cerebral oxygen metabolism and postoperative cognitive function in elderly patients requiring one-lung ventilation (OLV).Methods Sixty patients of both sexes,aged 65-80 yr,weighing 45-75 kg,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,scheduled for elective radical resection for esophageal cancer performed via video-assisted thoracoscope with general aneshesia,were divided into 2 groups (n =30 each)using a random number table:volume-controlled ventilation group (group VCV) and protective ventilation group (group PV).In group VCV,the tidal volume (VT) was set at 10 ml/kg during two-lung ventilation (TLV) and at 7 ml/kg during OLV.In group PV,the VT was set at 7 ml/kg during TLV and at 5 ml/kg during OLV with positive end-expiratory pressure of 5 cmH2O,and lung recruitment maneuver was performed every 45 min with inspiratory pressure at 15,20 and 25 cmH2O,PEEP 5 cmH2O,3 breaths per pressure,5 s/breath.Before induction of anesthesia (T1),at 10 min of TLV (T2),at 30 min of OLV (T3) and at 15 min after restoration of TLV (T4),blood samples were taken from the radial artery and jugular bulb for blood gas analysis,and pH value,arterial oxygen partial pressure (PaO2),arterial carbon dioxide partial pressure (PaCO2),arterial oxygen saturation (SaO2) and jugular venous oxygen saturation (SjvO2) were recorded.Oxygenation index (OI),intrapulmonary shunt (Qs/Qt),arteriovenous blood O2 content difference (Da-jvO2) and cerebral O2 extraction rate (CERO2) were calculated at the same time.Cognitive function was assessed using Mini-Mental State Examination at 7 days and 1 month after operation,and the development of postoperative cognitive dysfunction was recorded.Results PaO2,DajvO2,CERO2 and Qs/Qt were significantly higher and SjvO2 and OI were lower at T2-4 than at T1 in two groups (P＜0.05).PaO2,SjvO2 and OI were significantly lower and Qs/Qt and CERO2 were higher at T3 than at T2,and Da-jvO2 was higher at T3-4 than at T2 in two groups (P＜0.05).Compared with group VCV,PaO2,PaCO2,SjvO2 and OI were significantly increased and Qs/Qt,Da-jvO2 and CERO2 were decreased at T3,the Mini-Mental State Examination scores were increased on postoperative day 7,and the incidence of postoperative cognitive dysfunction was decreased in group PV (P＜O.05).Conclusion Lungprotective ventilation is helpful in improving postoperative brain function of elderly patients requiring OLV.

Objective To evaluate the effect of dexmedetomidine on the expression of gamma-aminobutyric acid(GABAA)receptors during ventilator-induced lung injury(VILI)in rats. Methods Thirty pathogen-free adult male Sprague-Dawley rats,weighing 280-320 g,were divided into 3 groups(n=10 each)using a random number table:control group(group C),group VILI and dexmedetomidine group(group Dex).The rats were mechanically ventilated for 4 h with the tidal volume of 40 ml/kg to establish VILI model. Dexmedetomidine 50 μg/kg was injected intraperitoneally after the rats were anesthetized in group Dex,while the equal volume of normal saline was given instead in C and VILI groups. The animals were sacrificed at 4 h of mechanical ventilation,the lungs were removed for examination of pathological changes which were scored,bronchoalveolar lavage fluid(BALF)was collected for determination of concentrations of total protein,interleukin-1 beta(IL-1β),IL-6 and tumor necrosis factor-alpha(TNF-α),and the lung specimens were obtained for determination of the wet/dry weight ratio(W/D ratio),alveolar fluid clearance(AFC)and expression of GABAA receptors,IL-1β,IL-6 and TNF-α mRNA in lung tissues. Results Compared with group C,the W/D ratio,pathological scores,expression of total protein,IL-1β,IL-6 and TNF-α in BALF and expression of IL-1β,IL-6 and TNF-α mRNA in lung tissues were significantly increased,and the GABAA receptor expression and AFC were decreased in VILI and Dex groups(P<0.05).Compared with group VILI,the W/D ratio,pathological scores,expression of total protein,IL-1β,IL-6 and TNF-α in BALF and expression of IL-1β,IL-6 and TNF-α mRNA in lung tissues were significantly decreased,and the GABAA receptor expression and AFC were increased in group Dex(P<0.05).Conclusion The mechanism by which dexmedetomidine reduces VILI is related to up-regulation of GABAA receptor expression in rats.