Background The measurement of retinal nerve fiber layer (RNFL) by Cirrus optical coherence tomography (OCT) has been applied widely in ophthalmology.However,previous assessment of RNFL is based on spatial measurement,while the evaluation based on optical characteristics of OCT can offset the shortcomings of spatial measurement in some eye diseases.Objective This study was to analyze the optical characters of RNFL measured by OCT and its correlation with age in healthy Chinese individuals.Methods Four hundred and six normal healthy subjects were collected in Shanghai Shibei Hospital from June 2011 to June 2012,with the age of 40-83 years old.Macular RNFL was unilateral imaged using a Cirrus OCT device with 5 line raster macular scan mode under the approval of Ethic Committee of Shanghai Shibei Hospital and informed consent of subjects.A customized software was used to measure RNFL optical characters,including absorbance (A value) and attenuate coefficient.The difference of the measured parameters in different genders was compared.The correlations between RNFL optical characters and age were analyzed by linear regression analysis.Results The data of 353 eyes were included in the final outcomes.The RNFL thickness,A value and attenuate coefficient were (35.1 ±4.4) μm,121.6 ±5.3 and 2.06 ±0.25,respectively.RNFL thickness and A value showed significantly negative correlations with age (r=-0.487,-0.571,both at P＜0.01) with the regression equation Y=-0.17 X+45.23 and Y=-0.24 X+ 135.82,while a positive correlation was found between the attenuate coefficient and age (r=0.368,P＜0.01) with the regression equation Y=0.01 X+1.63.RNFL thickness and A value showed weaker positive correlations with OCT signal intensity (rs =0.128,P =0.016;rs =0.284,P＜0.01),but no remarked correlation was seen between the attenuate coefficient and OCT signal intensity (rs =-0.053,P=0.319).Conclusions Age of subjects affects the parameters of OCT optical characteristics in normal populaition.Age-related RNFL change in optical characters of OCT should be considered before concluding optical parameters.

Objective To investigate the efficacy of dexmedetomidine on sedation in post-cardiac surgery patients with NIV intolerance.The changes of respiratory function and hemodynamics of the patients as well as non-invasive ventilation (NIV) failure rate were also under evaluation.Methods Thirty-five post-cardiac surgery patients with NIV intolerance and hypoxemia were enrolled in this prospective study.All patients were sedated with dexmedetomidine.NIV was standardized according to the uniform protocol.The main outcome was NIV success (avoiding endotracheal intubation) or NIV failure (requiring endotracheal intubation or die).The cardiorespiratory parameters (BP,HtR and RR) and artery blood gas analysis were prospectively recorded before and after sedation.The respiratory function and hemodynamics changes in both groups (NIV success group and NIV failure group) were then evaluated.Factors independently associated with NIV failure were identified using a logistic regression model.Results Twenty out of 35 patients (57.14％) survived while 15 (42.86％) patients failed NIV.After 1 h and 4 h of NIV with dexmedetomidine sedation,respiratory rate in both groups were decreased compared with baseline,especially in NIV success group.The PaO2/FiO2 was also improved after 1h and 4h of NIV treatment compared with baseline.The improvement was more significantly in NIV success group.The heart rate was decreased compared with baseline with no differences between two groups.There were no significant changes on PaCO2 and mean arterial pressure (MAP) during the treatment.The respiratory and hemodynamics variables identified as predictors of NIV failure were included in a multivariate logistic regression.RR ＞ 23 time/min (OR =3.2,95％ CI:2.043 ～ 4.301,P ＜ 0.01) 1 h after NIV,RR ＞ 20 time/min (OR =2.1,95％ CI:1.659～3.231,P=0.025) 4 h after NIV,PaO2/FiO2 ＜178 mmHg (OR=2.4,95％CI:1.892 ～ 3.287,P ＜0.01) 1 h after NIV and PaO2/FiO2 ＜ 185 mmHg (OR =1.7,95％ CI:1.243 ～ 2.365,P =0.041) 4 h after NIV independendy predicted NIV failure.Conclusions Dexmedetomidine might be considered as an effective and safe sedative for post-cardiac surgery patients with NIV intolerance.Early identification of predictors of NIV failure may facilitate early intervention.

Background and Objectives: Chronic obstructive pulmonary disease (COPD) is a common, frequently-occurring disease and poses a major health concern. Unfortunately, there is current no effective treatment for COPD, particularly emphysema. Recently, experimental treatment of COPD using mesenchymal stem cells (MSCs) mainly focused on bone marrow-derived MSCs (BM-MSCs). Human umbilical cord-derived MSCs (hUC-MSCs) have more advantages compared to BM-MSCs. However, studies on the role of hUC-MSCs in management of COPD are limited. This study sought to explore the role of hUC-MSCs and its action mechanisms in a rat model of VEGF receptor blocker SU5416-injured emphysema. Methods: and Results: hUC-MSCs were characterized by immunophenotype and differentiation analysis. Rats were div-ided into four groups: Control, Control＋MSC, SU5416 and SU5416＋MSC. Rats in model group were administered with SU5416 for three weeks. At the end of the second week after SU5416 administration, model group were infused with 3×106 hUC-MSCs through tail vein. After 14 days from hUC-MSCs transplantation, rats were euthanized and data were analyzed. HE staining and mean linear intercepts showed that SU5416-treated rats exhibited typical emphysema while emphysematous changes in model rats after hUC-MSCs transplantation disappeared completely and were restored to normal phenotype. Furthermore, hUC-MSCs inhibited apoptosis as shown by TUNEL and Western blotting.ELISA and Western blotting showed hUC-MSCs rescued VEGF-VEGFR2-AKT pathway in emphysematous lungs. Conclusions The findings show that hUC-MSCs effectively repair the emphysema injury. This study provides the first evidence that hUC-MSCs inhibit apoptosis via rescuing VEGF- VEGFR2-AKT pathway in a rat model of emphysema.