ABSTRACT
AIM: To explore the role of PI3K/Akt/nNOS in Zhouluotong extract resisting diabetic peripheral neuropathy.METHODS:The Schwann cells were divided into normal group ( D-glucose 25 mmol/L) , model group ( D-glucose 100 mmol/L) , Zhouluotong extract Z-6 +high glucose group, Zhouluotong +high glucose group, mecobalamine+high glucose group.The viability, nitric oxide content and the Ca2+-ATPase activity in Schwann cells were determined by Cell Counting Kit-8 , nitric oxide assay kit and Ca2+-ATPase assay kit, respectively.The apoptosis of Schwann cells were analyzed by flow cytometry.The expression of Bcl-2, Bcl-xL, Bax, Bak and caspase-3, and the phosphorylation levels of nNOS and Akt were determined by Western blotting.The signal pathway of PI3K/Akt was explored by dominant negative PI3K and Akt (δp85 and DN-Akt) transient transfection assay.RESULTS:Under high-glucose culture, the cell viability, nitric oxide content in culture supernatant, the expression of Bcl-2 and Bcl-xL, and the phosphorylation levels of Akt and nNOS in the Schwann cells were significantly increased.The cell apoptosis, the expression of Bax, Bak and caspase 3 in the Schwann cells were significantly decreased by Zhouluotong extract Z-6, compared with model group.In-creased nitric oxide content and the up-regulation of nNOS were observed.However, the effects of blocking PI3K/Akt, the upstream pathway of nNOS , by transfection with DN-δp85 on Akt phosphorylation in the Schwann cells was still unclear. CONCLUSION:Zhouluotong extract Z-6 changes the phosphorylation of nNOS, and the expression of anti-apoptotic fac-tors , caspase-3 and pro-apoptotic factors in Schwann cells under high-glucose culture, thus reducing apoptosis and elevating viability.The relationship to PI3K/Akt/nNOS pathway needs further investigation.
ABSTRACT
Objective To discuss the clinical significance of fluid management of severe patients according to arterial pressure-based cardiac output (APCO) monitoring volume responsiveness index.Methods A retrospective cohort study was conducted.The severe patients were selected from the intensive care unit (ICU) of the First Hospital of Jilin University from June 1st,2012 to December 31st,2013.The hemodynamic parameters were monitored by APCO,and the fluid resuscitation was managed by stroke volume variation (SVV) and passive leg-raising test (PLR) when the acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score ≥ 15,heart rate ＞ 100 bpm with the result that the preload and heart function could not be evaluated.The heart rate,SVV,lactic acid (Lac) and central venous pressure (CVP) and curative effect were recorded before and after carrying out fluid management strategy.The criteria of clinical effective was defined as heart rate decreased and (or) stroke volume (SV) increased ≥ 10％,accompanied by blood Lac and SVV decreased,other than,the cases did not meet above criteria were considered ineffective.Results Sixty-eight patients were enrolled in the study.① Before carrying out fluid management strategy:40 cases with CVP＞ 12 cmH2O (1 cmH2O=0.098 kPa),and 16 cases with 5-12 cmH2O,12 with ＜5 cmH2O.SVV＞13％ in 35 cases,SVV ＜ 13％ in 9 cases.PLR positive in 18 cases,and PLR negative in 6 cases.It was implicated that the patients with poor preload (SVV ＞ 13％ and PLR positive) accounted by 77.9％ (53/68).② There were 49 effective cases and 19 ineffective cases 4 hours after carrying out fluid management strategy,and the effective rate was 72.06％ (49/68).While there were 56 effective cases and 12 ineffective cases after 12 hours,and the total effective rate was 82.35％ (56/68).③ In effective group,heart rate,SVV,Lac after fluid management strategy were significantly lower than those before fluid management strategy [4 hours after fluid management strategy:heart rate (bpm) 112.45 ± 13.53 vs.129.55 ± 15.49,SVV (15.47 ± 6.32)％ vs.(21.20 ± 7.40)％,Lac (mmol/L) 4.16 ± 3.12 vs.6.21 ± 4.11 ; 12 hours after fluid management strategy:heart rate (bpm) 110.02 ± 13.92 vs.129.61 ± 14.93,SVV (14.61 ± 15.52)％ vs.(20.66 ± 7.40)％,Lac (mmol/L) 3.35 ± 2.26 vs.6.11 ± 4.02,P＜0.05 or P＜0.01],while there was no significant difference in those markers between before and after fluid management strategy in ineffective group [4 hours after fluid management strategy:heart rate (bpm) 119.53 ± 11.68 vs.125.79 ± 11.58,SVV (16.95 ±6.48)％ vs.(18.47 ±4.96)％,Lac (mmol/L) 5.55 ± 3.80 比 6.54 ± 3.72 ; 12 hours after fluid management strategy:heart rate (bpm) 115.92 ± 11.71 vs.123.40 ± 11.59,SVV (17.17 ± 6.09)％ vs.(19.42 ± 8.25)％,Lac (mmol/L) 6.33 ± 3.40 vs.7.21 ± 3.81,all P＞ 0.05].CVP only at 12 hours after fluid management strategy in effective group was significantly higher than that before fluid management strategy (cmH2O:12.88 ± 3.38 vs.11.27 ± 4.97,P＜0.05).Conclusion SVV monitored by APCO is a good indicator of volume responsiveness index,which can be used as an important reference combined with PLR for fluid management of severe patients.