Chemokine receptor 7 promotes the paracrine of hepatocyte growth factor by mesenchymal stem cells via inhibitor of differentiation-1 / 中华危重病急救医学

Objective:To investigate the possible mechanism of mesenchymal stem cells (MSC) secreting hepatocyte growth factor (HGF).Methods:① C57BL/6 mouse mesenchymal stem cells (mMSC) were cultured in vitro, and mMSC with high expression of chemokine receptor 7 (CXCR7) were transduced by lentivirus plasmid. Blank control group and empty carrier control group were set at the same time. After 20 generations of cell culture, the transfection efficiency was identified by fluorescence microscopy and flow cytometry. The mRNA expression levels of CXCR7 in mMSC were detected by real-time fluorescent quantitative reverse transcription-polymerase chain reaction (RT-PCR). ② mMSC with passage number 4-6 were divided into MSC control group [MSC-blank group, 100 μg/L lipopolysaccharide (LPS) was added to wild-type MSC], highly expressed CXCR7 group (MSC-OE-CXCR7 group, 100 μg/L LPS was added to mMSC transduced by lentivirus plasmid with high expression of CXCR7), highly expressed CXCR7 control group (MSC-OENC-CXCR7 group, 100 μg/L LPS was added to mMSC transduced by no load lentivirus plasmid), CXCR4 inhibitor group (MSC-IE-CXCR4 group, 100 μg/L LPS was added to mMSC after 0.1 mg/L CXCR4 inhibitor TC14012 pretreatment for 24 hours), and CXCR4 inhibitor control group (MSC-IENC-CXCR4 group, 100 μg/L LPS was added to mMSC after DMEM culture medium with equal amount of TC14012 pretreatment for 24 hours). Cells in each group were collected after treatment with LPS, and mRNA expression of inhibitor of differentiation-1 (ID-1) was detected by RT-PCR. The cell supernatant was collected, and the levels of HGF were detected by enzyme linked immunosorbent assay (ELISA). Results:① The high expression of CXCR7 for mMSC which were transduced through lentivirus plasmid were successfully constructed detected by fluorescence microscope and flow cytometry. Compared with the blank control group, the expression of CXCR7 mRNA in the lentivirus with high expression of CXCR7 group was significantly increased (2 -ΔΔCt: 5.81±0.97 vs. 1.02±0.12, P < 0.05). There was no significant difference in CXCR7 mRNA expression between the empty carrier control group and the blank control group (2 -ΔΔCt: 0.95±0.22 vs. 1.02±0.12, P > 0.05). ②Compared with the MSC-blank group, high expression of CXCR7 in MSC-OE-CXCR7 group or inhibition of CXCR4 in MSC-IE-CXCR4 group could induce high expression of ID-1 mRNA in mMSC (2 -ΔΔCt: 5.56±0.66, 2.47±0.58 vs. 1.00±0.10, both P < 0.05) and increase HGF exocrine level (ng/L: 632.02±149.98, 217.21±40.53 vs. 108.53±24.62, both P < 0.05). However, there were no significant differences in ID-1 mRNA expression and HGF exocrine level of mMSC among MSC-OENC-CXCR7 group, MSC-IENC-CXCR4 group and MSC-blank group [ID-1 mRNA (2 -ΔΔCt): 1.01±0.27, 1.21±0.32 vs. 1.00±0.10, HGF (ng/L): 133.56±25.19, 107.11±25.30 vs. 108.53±24.62, both P > 0.05]. Conclusion:High expression of CXCR7 or inhibition of CXCR4 in MSC can increase the expression of ID-1 and promote the secretion of HGF, thus promoting pulmonary microvascular endothelial repair.

Validation of Reference Genes for Quantitative Real-Time PCR in Bovine PBMCs Transformed and Non-transformed by Theileria annulata

Theileria annulata is a tick-borne intracellular protozoan parasite that causes tropical theileriosis, a fatal bovine lymphoproliferative disease. The parasite predominantly invades bovine B lymphocytes and macrophages and induces host cell transformation by a mechanism that is not fully comprehended. Analysis of signaling pathways by quantitative real-time PCR (qPCR) could be a highly efficient means to understand this transformation mechanism. However, accurate analysis of qPCR data relies on selection of appropriate reference genes for normalization, yet few papers on T. annulata contain evidence of reference gene validation. We therefore used the geNorm and NormFinder programs to evaluate the stability of 5 candidate reference genes; 18S rRNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ACTB (β-actin), PRKG1 (protein kinase cGMP-dependent, type I) and TATA box binding protein (TBP). The results showed that 18S rRNA was the reference gene most stably expressed in bovine PBMCs transformed and non-transformed with T. annulata, followed by GAPDH and TBP. While 18S rRNA and GAPDH were the best combination, these 2 genes were chosen as references to study signaling pathways involved in the transformation mechanism of T. annulata.

Effects of high-frequency oscillatory ventilation and conventional mechanical ventilation on oxygen metabolism and tissue perfusion in sheep models of acute respiratory distress syndrome / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>High-frequency oscillatory ventilation (HFOV) allows for small tidal volumes at mean airway pressures (mPaw) above that of conventional mechanical ventilation (CMV), but the effect of HFOV on hemodynamics, oxygen metabolism, and tissue perfusion in acute respiratory distress syndrome (ARDS) remains unclear. We investigated the effects of HFOV and CMV in sheep models with ARDS.</p><p><b>METHODS</b>After inducing ARDS by repeated lavage, twelve adult sheep were randomly divided into a HFOV or CMV group. After stabilization, standard lung recruitments (40 cmH2O × 40 seconds) were performed. The optimal mPaw or positive end-expiratory pressure was obtained by lung recruitment and decremental positive end-expiratory pressure titration. The animals were then ventilated for 4 hours. The hemodynamics, tissue perfusion (superior mesenteric artery blood flow, pHi, and Pg-aCO2), oxygen metabolism and respiratory mechanics were examined at baseline before saline lavage, in the ARDS model, after model stabilization, and during hourly mechanical ventilation for up to 4 hours. A two-way repeated measures analysis of variance was applied to evaluate differences between the groups.</p><p><b>RESULTS</b>The titrated mPaw was higher and the tidal volumes lower in the HFOV group than the positive end-expiratory pressure in the CMV group. There was no significant difference in hemodynamic parameters between the HFOV and CMV groups. There was no difference in the mean alveolar pressure between the two groups. After lung recruitment, both groups showed an improvement in the oxygenation, oxygen delivery, and DO2. Lactate levels increased in both groups after inducing the ARDS model. Compared with the CMV group, the superior mesenteric artery blood flow and pHi were significantly higher in the HFOV group, but the Pg-aCO2 decreased in the HFOV group.</p><p><b>CONCLUSION</b>Compared with CMV, HFOV with optimal mPaw has no significant side effect on hemodynamics or oxygen metabolism, and increases gastric tissue blood perfusion.</p>

Impact of a computer-driven knowledge-based system of SmartCare on weaning patients with chronic obstructive pulmonary diseases detached from mechanical ventilation / 中华急诊医学杂志

ObjectiveTo compare the outcomes of 3 modes of weaning,e.g.SmartCare (a computerdriven knowledge-based system),spontaneous breathing trials (SBBT) and empirical methods,used in patients with chronic obstructive pulmonary diseases (COPD) weaned off mechanical ventilation.MethodsSixty-eight COPD patients were enrolled and randomly (random number) assigned to receive SmartCare (SC group,n =24),SBT (SBT group,n=24) or empirical methods (EM group,n =20).The following data were recorded including beginning of weaning:time consumed for weaning,duration of mechanical ventilation,length of ICU stay,success rate of weaning,survival rate during hospitalization and the complications of mechanical ventilation.The patients were considered as successfully weaned when they were able to tolerate at least 48 consecutive hours of spontaneous breathing.ResultsTime required for weaning and total time for mechanical ventilation in SC group were greatly shorter than those in EM group (P =0.002,0.002),but there were no differences between SC group and SBT group (P =0.540,0.573).Though the length of ICU stay (7.5 d) in SBT group was notably shorter than that in EM group (82.5 d) (P=0.015),there was no difference between SBT group and SC group (8.0 d).Weaning success rate was greater in the SC group (88.3％) than that in EM group (50.0％),but there was no difference between SBT group (66.7％ ) and SC group.No significant differences in survival rate during hospitalization,rate of re-intubation,self-extubation and need for noninvasive ventilation were found among three groups.ConclusionsCompared to empirical methods for weaning,SmartCare could greatly increase the success rate of weaning,but it was not superior to SBT.

The effect of stress dose glucocorticoid on patients with acute respiratory distress syndrome combined with critical illness-related corticosteroid insufficiency / 中华内科杂志

Objective To investigate the effect of stress dose glucocorticoid on patients with acute respiratory distress syndrome (ARDS) combined with critical illness-related corticosteroid insufficiency (CIRCI).Methods All early ARDS patients combined with CIRCI were screened by an adrenal corticotrophic hormone (ACTH) test and randomly divided into treatment group (hydrocortisone 100 mg intravenous,3 times/day,consecutively for 7 days,n =12 ) and control group (equivalent normal saline,n =14 ).General clinical data,changes of arterial blood gas,hemodynamics and respiratory mechanics were observed and recorded at admission and at 7 days after treatment.Ventilator-free and shock-free days,ICU stay within 28 days after admission were recorded and 28-day mortality was used as judge prognosis index.Results CIRCI rate in 45 early ARDS patients was 57.8％ ( 26 patients),and the shock rate was markedly higher in ARDS patients with CIRCI than patients without CIRCI (46.2％ vs 5/19 ).There were no significant differences in baseline parameters,oxygenation and illness severity between the treatment and control groups,except for markedly lower lactic level in the treatment group [ 2.7 ( 1.2,3.9 ) mmol/L vs 4.6 ( 2.5,6.3 ) mmol/L,P ＜ O.05].After 7 days of treatment,PaO2/FiO2 markedly increased,while heart rate obviously decreased in the both groups.Compared with the control group,survival time of patients was significantly longer and shock rate of the patients was markedly lower in treatment group within 28 days (5/12 vs 10/14,P ＜ 0.05).The 28-day mortality,which were adjusted by baseline arterial lactic,was lower in the treatment group (2.6/12 ) than in the control group (5.8/14) while with no significant difference ( P ＞ 0.05 ).There was no significant difference in complication incidence between the two groups.Conclusion Stress dose glucocorticoid could reduce shock incidence and prolong survival time,and has a tendency of lower 28-day mortality in early ARDS patients combined with CIRCI.

The evaluation value of severity and prognosis of septic shock patients based on the arterial-to-venous carbon dioxide difference / 中华内科杂志

Objective To assess the value of central venous-to-arterial carbon dioxide difference [ P( cv-a) CO2 ] in evaluation of disease severity and prognosis in patients with septic shock.Methods There were 45 consecutive resuscitated septic shock patients from April 2009 to October 2010 included immediately after their admission into our ICU.The patients were divided into low P(cv-a) CO2 group and high P(cv-a) CO2 group according to a threshold of 6 mm Hg ( 1 mm Hg=0.133 kPa).All patients were treated by early goal directed therapy (EGDT).The parameters of hemodynamics,lactate clearance rate,the Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ ) score,the sequential organ failure assessment (SOFA)score,6 h rate of EGDT achievement,the ICU mortality and 28 days in-hospital mortality were recorded for all patients.Results There were 30 patients in the low P(cv-a) CO2 group,and 15 in the high P(cv-a)CO2group.There were no significant differences between low P(cv-a) CO2 and high P(cv-a) CO2 patients in age,APACHE Ⅱ score and SOFA score (all P ＞ 0.05 ).Compared with the high P(cv-a)CO2 group,the low P(cv-a) CO2 group had higher cardiac index ( CI ) and 24 h CI,higher delivery O2 ( DO2 ) and 24 h DO2,higher central venous oxygen saturation ( ScvO2 ) [ (74 ± 9) ％ vs (67 ± 8) ％ ],lower lactate [ ( 3.4 ± 2.1 )mmol/L vs (5.7 ± 4.5 ) mmol/L] and higher △SOFA score [ (0.7 ± 1.8 ) vs ( - 0.4 ± 1.1 ) ],lower 24 h SOFA score [ (7.8 ± 2.0) vs (9.8 ± 2.0 ) ],higher 6 h rate of EGDT achievement ( 83.3％ vs 53.3 ％ )(P ＜ 0.05 ),however,there were no differences in 28 days mortality and ICU mortality between the two groups ( P ＞ 0.05 ).Conclusion P(cv-a) CO2 might be an indicator for predicting the severity of patients with septic shock and evaluating tissue perfusion.

The clinical application of pulmonary vascular permeability index on differential diagnosis of acute pulmonary edema / 中华内科杂志

Objective To assess the value of pulmonary vascular permeability index in differentiating acute lung injury (ALI) from cardiac pulmonary edema. Methods Critically ill patients with acute pulmonary edema were included from May, 2004 to September, 2008. Patients were divided into two groups, the ALI group and the cardiac pulmonary edema group (C group). Pulmonary vascular permeability index (PVPI) , intrathoracic blood volume (ITBVI) were determined by pulse indicator continuous cardiac output(PiCCO) system. Results ( 1 ) Thirty-four patients were enrolled, 22 cases in ALI group and 12 cases in C group. (2) The PVPI in patients of ALI group (2.7 ± 1.4) was higher than that of C group (1.9 ±0.6 ;P＜0.05). EVLWI and ITBVI did not have the significant difference between the two groups (P ＞0. 05). (3) PVPI was positively correlated with EVLWI(r = 0. 762) , negatively correlated with PaO2/ FiO2(r= -0.478). (4)ARDS was diagnosed in 13 cases, including 8 pulmonary cause(ARDSp) and 5 extra-pulmonary cause ( ARDSexp). PVPI, EVLW/ITBV and EVLWI of patients with ARDSexp were obviously higher than those with ARDSp. Conclusions PVPI may be useful for differentiating the types of pulmonary edema in the critically ill.

Use of extracorporeal membrane oxygenation on adults with adult acute respiratory distress syndrome: a meta-analysis and systematic review / 中华急诊医学杂志

Objective To investigate the effects of extracorporeal membrane oxygenation (ECMO) on survival of adult from acute respiratory distress syndrome (ARDS). Method We searched Pubmed, Embase, Cochrane Library, Web of Science databases to find relevant literatues on ECMO in treatment of ARDS, which are reported from January 1966 to June 2010. Meta analyses was performed. Results Three papers about randomized controlled trial (RCT) of evaluating ECMO in patients with severe ARDS were enrolled for analyses. Meta-analysis of the three randomized controlled trials revealed ECMO did not decrease the mortality of ARDS patients. However, the cumulative meta-analysis of randomized trials showed ECMO had a protective effect on patients with ARDS. The most recent observational studies suggested that ECMO significantly decreased the mortality of ARDS caused by H1 N1 viral pneumonia. Conclusions There is no evidence to prove the benefit of ECMO in patients with ARDS. However, ECMO should be considered to use in early stage of ARDS as a last rescue resort for potentially reversible severe acute respiratory failure. Further investigation of large sample of high quality RCTs is needed.

Effects of noninvasive positive pressure ventilation on mortality and rate of reintubation in mechanical ventilation patients after extubation: a meta-analysis / 中华急诊医学杂志

Objective To evaluate the effects of noninvasive positive pressure ventilation (NPPV)used after extubation on mortality and rate of reintubation in patients with acute respiratory failure (ARF).Method Pubmed, Embase, Web of Science databases were searched to collect data from randomized controlled trials (RCT) of the relevant subject from January 1995 to May 2010. Meta analysis of data about NPPV on mortality and rate of reintubation in patients after extubation carried out by using the methods recommended by the Cochrane Collaboration. Results Six RCTs included sample size of 381 NPPV and 379routine medical care. In total, the mortalities of patients in NPPV group and routine medical care group were 18.6% (62/334) vs. 21.6% (72/333), respectively, and the rates of reintubation of the two groups were 30.2% (115/381) vs. 33.5% (127/379), respectively. Compared with routine medical care, NPPV did not significantly reduce the mortality ( OR: 0.83, 95% CI =0.57 ～ 1.21 ,P =0.34) and rate of reintuation( OR: 0.83, 95% CI = 0.59 ～ 1.16, ( P = 0.27). When the analysis was focused to the four studies of them in which patients received NPPV as soon as extubation, the results were quite different. From these four studies, the mortalities of patients in NPPV group and routine medical care group were 12. 2% (22/181) vs.23.9% (44/184),(P=0.004), and the rate of reintubation of the two groups were 14.0% (32/228) vs.20.4% (47/230), (P =0.07). Compared with routine medical care, early application of NPPV to patients after extubation reduced the mortality. Conclusions This study suggests the favorable effects of early application of NPPV to patients after extubation on the mortality of acute respiratory failure.