Removing acoustic ringing baseline curvature in 13 C NMR spectra for quantitative analyses.

13 C nuclear magnetic resonance (NMR) is traditionally considered an insensitive technique, requiring long acquisition times to measure dilute functionalities on large polymers. With the introduction of cryoprobes and better electronics, sensitivity has improved in a way that allows measurements to take less than 1/20th the time that they previously did. Unfortunately, a high Q-factor with cryoprobes creates baseline curvature related to acoustic ringing that affects quantitative NMR analyses. Manual baseline correction is commonly used to compensate for the baseline roll, but it is a time-intensive process. The outcome of manual baseline correction can vary depending on processing parameters, especially for complicated spectra. Additionally, it can be challenging to distinguish between broad peaks and baseline rolls. A new anti-ring pulse sequence (zgig_pisp) was previously reported to improve on the incumbent single pulse experiment (zgig). The original report presented limited comparison data with 13 C NMR, but a thorough validation is needed before broader implementation can be considered. In this work, we report the round-robin testing and comparison of zgig_pisp and zgig pulse sequences. During the testing phase, we found that zgig_pisp is practically equivalent to zgig to ±2% for the majority of integrals examined. Additionally, a short broadband inversion pulse (BIP) was demonstrated as an alternative to the originally reported adiabatic CHIRP shaped pulse. The zgig_pisp pulse sequence code for Bruker spectrometers is also simplified.

Carnosol protects against spinal cord injury through Nrf-2 upregulation.

BACKGROUND: Carnosol is an ortho-diphenolic diterpene with excellent antioxidant potential. The present study was designed to identify the protective role of carnosol against spinal cord injury (SCI)-induced oxidative stress and inflammation in Wistar rats. METHODS: In the present study, oxidative stress status was determined through estimating total antioxidant capacity, total oxidant status, lipid peroxide content, protein carbonyl and sulfhydryl levels, reactive oxygen species (ROS), antioxidant status (superoxide-dismutase, catalase, glutathione, glutathione peroxidase, glutathione-S-transferase). Inflammatory effects were determined by analyzing the expression of NF-κB and COX-2 through Western blot analysis. Further, carnosol-mediated redox homeostasis was analyzed by determining p-AKT and Nrf-2 levels. RESULTS: SCI resulted in a significant increase in oxidative stress status through increased ROS generation, total oxidant levels, lipid peroxide content, protein carbonyl and sulfhydryl levels. The antioxidant status in SCI rats was significantly reduced, indicating imbalance in redox status. In addition, the expression of NF-κB and COX-2 was significantly upregulated, while p-AKT and Nrf-2 levels were downregulated in SCI rats. However, treatment with carnosol showed a significant enhancement in the antioxidant status with concomitant decline in oxidative stress parameters. Further, carnosol treatment regulated the key proteins in inflammation and redox status through significant downregulation of NF-κB and COX-2 levels and upregulation of p-AKT and Nrf-2 expression. CONCLUSION: Thus, the present study shows for the first time on the protective role of carnosol against SCI-induced oxidative stress and inflammation through modulating NF-κB, COX-2 and Nrf-2 levels in Wistar rats.

Increased cardiac index attenuates septic acute kidney injury: a prospective observational study.

BACKGROUND: The relationship between cardiac output and septic acute kidney injury (AKI) remains unclear. The purpose of this study was to assess the association between the cardiac index (CI) and the renal outcomes in patients with septic shock. METHODS: A one-year prospective cohort study was performed in the surgical and medical ICU of a teaching hospital in Nanjing, China. Twenty-nine septic shock patients who required early goal-directed fluid resuscitation were consecutively included. Pulse indicator continuous cardiac output (PiCCO) device was used to measure hemodynamic parameters before and after early goal-directed therapy (EGDT). Based on CI changes after EGDT, patients were assign to the CI increased group or the CI constant group, respectively. The incidence of poor renal outcome, which was defined as AKI on admission without recovery in following three days or new onset AKI within 28 days, was recorded. We investigated whether an increased CI was associated with a better renal outcome. RESULTS: After EGDT, there were 16 patients in the CI increased group and 13 patients in the CI constant group. The incidence of poor renal outcome was lower in CI increased group than in the CI constant group (6% vs. 62%; P = 0.003) with a relative risk of 0.10. The logistic regression showed that the CI percent change was associated with renal outcome, with an odd ratio of 0.003 (P = 0.056) after adjustment of possible confounding factors. The CI percent change would predict a good renal outcome (AU ROC 0.739, P = 0.012) with moderate accuracy (sensitivity 75% and specificity 89%) when using a 10% cut-off value from Youden index. The CI percent change was also positively correlated with creatinine clearance (CCr) after EGDT (ρ = 0.548; P = 0.002). CONCLUSIONS: The increased CI after EGDT was a protective factor for kidney in patients with septic shock. A CI increased above 10% could be potentially used to predict development and reversibility of AKI in septic shock patients. TRIAL REGISTRATION: Clinicaltrials.gov:NCT01862588 (May 13, 2013).

[Effect of Xuebijing injection treatment on acute respiratory distress syndrome: a multicenter prospective randomized control clinical trial].

OBJECTIVE: To assess the therapeutic effect of Xuebijing injection on adult patients with acute respiratory distress syndrome (ARDS). METHODS: A multicenter prospective randomized control study was conducted at 10 intensive care units in Jiangsu province. A total of 172 early ARDS patients were randomly divided into Xuebijing treatment and control groups. All patients received routine therapy of ARDS while additional Xuebijing injection 100 ml was administered in the treatment group intravenously for 7 days. Lung injury score, acute physiology and chronic health evaluation II (APACHE II) score, multiple organ dysfunction score (MODS) and PaO2/FiO2 of the patients was recorded before and after treatment. Mortality at 28 days and the duration of mechanical ventilation were compared between two groups. RESULTS: Ninety-one patients were assigned to receive Xuebijing injection and 81 patients as control; Mortality at Days 28 and 90, the duration of mechanical ventilation and ventilation free days showed no difference between two groups (P > 0.05). PaO2/FiO2 improved after randomization versus pre-treatment in all patients. There was no significant difference between two groups. Murray scores were not significantly different between two groups. In a subgroup analysis of patients with pulmonary infection, pulmonary contusion and extra-pulmonary cause, two groups had no difference in mortality at Day 28, mortality at Day 90, the duration of mechanical ventilation, ventilation free days and days of ICU stay (P > 0.05). CONCLUSION: The treatment of Xuebijing injection early in course of ARDS does not improve the mortality of ARDS patients. But it may improve lung function and oxygenation. Further studies are warranted.

[Use of extracorporeal membrane oxygenation in adults with acute respiratory distress syndrome: a meta-analysis].

OBJECTIVE: To evaluate the effects of extracorporeal membrane oxygenation (ECMO) on mortality in adult patients with acute respiratory distress syndrome (ARDS). METHODS: Literature concerning randomized controlled trials (RCTs), case-control studies and prospective cohort studies from January 1966 to July 2011 on ECMO for the treatment of ARDS patients was retrieved by electronic and manual search. Meta-analysis of the use of ECMO in the treatment of ARDS patients was conducted using the methods recommended by the Cochrane Collaboration's software RevMan 5.0. RESULTS: Three papers reporting RCTs and 6 papers concerning observational cohort studies of using ECMO in patients with severe ARDS were enrolled for analysis. Meta-analysis of the 3 RCTs (310 patients, 159 of them treated with ECMO) revealed ECMO did not decrease the mortality of ARDS patients [odds ratio (OR)=0.75, 95% confidence interval (95%CI) 0.45-1.24, P = 0.27]. Meta-analysis of the all 9 studies (1058 patients, 386 of them treated with ECMO) revealed ECMO increased the mortality of ARDS patients (OR=1.58, 95%CI 0.94-2.67, P = 0.08). CONCLUSION: There is no evidence to prove that ECMO is beneficial in adult patients with ARDS, therefore further investigation with a large sample of high quality RCT is warranted.

[A meta-analysis of the effects of direct hemoperfusion with polymyxin B-immobilized fiber on prognosis in severe sepsis].

OBJECTIVE: To investigate the effects of direct hemoperfusion with polymixin B-immobilized fiber (DHP-PMX) in patients with sepsis. METHODS: We searched Pubmed, Embase, Web of Science databases and identified relevant randomized controlled trials (RCT) from January 1995 to May 2010. Meta-analysis of DHP-PMX on mortality and levels of endotoxin in patients with sepsis were conducted using the methods recommended by the Cochrane Collaboration. RESULTS: Eleven RCTs were included. Eight of them included the mortality of patients (sample size: 211 DHP-PMX and 178 conventional medical therapy). In total, the mortalities of patients with sepsis in DHP-PMX group and conventional group were 37.4% (79/211) and 68.5% (122/178) respectively. Compared with the conventional medical therapy, DHP-PMX appeared to significantly reduce mortality (OR = 0.24, 95%CI 0.16 - 0.38, P < 0.000 01). The results were similar when two RCTs enrolling patients with methicillin resistant staphylococcus aureus (MRSA) infections were excluded (OR = 0.27, 95%CI 0.17 - 0.45, P < 0.000 01). When the analysis was limited to the nine studies that reported 28- to 30-day mortality, results were unchanged (OR = 0.29, 95%CI 0.17 - 0.48, P < 0.000 01). Six RCTs had the available data of endotoxin. The level of endotoxin decreased 31 ng/L(95%CI 22.46 - 39.55) after DHP-PMX therapy, and the decreasing was statistically significant (P < 0.000 01), while the level of endotoxin in patients of conventional group did not change (P = 0.94). CONCLUSIONS: This study suggests a favorable effects of DHP-PMX on mortality and endotoxin decreasing in patients with sepsis. However, lack of enough cases and blinding need to be considered. Further investigation with large sample of high quality RCTs is needed.

[Timing of tracheotomy on the prognosis of patients with prolonged mechanical ventilation: a meta-analysis of randomized controlled trials].

OBJECTIVE: To evaluate the effect of timing of tracheotomy on the prognosis of prolonged mechanically ventilated patients. METHODS: Randomized controlled trials (RCTs) that studied the effect of timing of tracheotomy on the prognosis of prolonged mechanically ventilated patients were searched from Pubmed, Embase, The Cochrane Library, CBM during January 1990 to June 2010. The quality of the RCTs was evaluated. Meta-analysis of timing of tracheotomy on the prognosis of prolonged mechanically ventilated patients were conducted using the methods recommended by the Cochrane Collaboration. Definition of early tracheotomy was the patients performed tracheotomy during 10 days after admission to hospital or ICU, mechanical ventilation or intubation. Late tracheotomy was defined tracheotomy performed beyond 10 days of admission to hospital or ICU, mechanical ventilation or intubation; or those mechanically ventilated through intubation all the time. RESULTS: Eight hundred and twenty eight patients, 411 in early tracheotomy group and 417 in late tracheotomy group, from 6 RCTs were included in the analysis of data. The meta-analysis showed that early tracheotomy could reduce mortality of patients (RR: 0.81, 95%CI: 0.66 - 0.99, P = 0.04); but it didn't significantly alter the incidence of pneumonia (RR:0.89, 95%CI: 0.68 - 1.17, P = 0.41), mechanical ventilation days (mean difference: -2.19, 95%CI: -9.86 - 5.49, P = 0.58) and length of ICU stay (mean difference: -5.65, 95%CI: -17.11 - 5.81, P = 0.33). CONCLUSIONS: In critically ill adult patients who require prolonged mechanical ventilation, early tracheotomy performed at an earlier stage reduces the mortality, but doesn't reduce the incidence of pneumonia and shorten the mechanical ventilation days and ICU length of stay. But more high quality RCTs are required to confirm it.

[Passive leg raising predicts volume responsiveness in patients with septic shock].

OBJECTIVE: To evaluate the hemodynamic response to passive leg raising (PLR) indicates fluid responsiveness in patients with septic shock. METHODS: Twenty patients with septic shock, considered for fluid challenge (FC), were enrolled in the study from June 2009 to May 2010. Hemodynamic changes were determined by pulse-contour derived cardiac index at baseline, before and after PLR, return to baseline for 10 min, before and after fluid challenge (250 ml saline for 10 min). An increase of SV after fluid challenge (FC-ΔSV) ≥ 10% were defined responders. RESULTS: Twenty patients with septic shock were included in the study. PLR and fluid challenge were performed 46 instances, among which 15 instances were defined as response group. SV and pulse pressure induced by PLR (PLR-ΔSV and PLR-ΔPP) were increased significantly in response group [(76 ± 19) ml vs. (65 ± 18) ml, (73 ± 20) mmHg vs. (62 ± 20) mmHg (1 mmHg = 0.133 kPa), P < 0.05], while in nonresponse group there were no significant change. PLR-ΔSV and PLR-ΔPP were correlated with FC-ΔSV (r = 0.51, P = 0.001; r = 0.45, P = 0.006), central venous pressure (CVP) were unrelated with FC-ΔSV. Area under curve (AUC) for PLR-ΔSV, PLR-ΔPP and stroke volume variation (SVV) were 0.846, 0.791 and 0.708. PLR-ΔSV ≥ 12.5% predicted fluid responsiveness with sensitivity of 80% and specificity of 93.5%. PLR-ΔPP ≥ 9.5% predicted fluid responsiveness with sensitivity of 73.3% and specificity of 83.9%. CONCLUSIONS: PLR-ΔSV and PLR-ΔPP can predict fluid responsiveness in patients with septic shock. PLR-ΔSV and PLR-ΔPP have a greater ability in predicting volume responsiveness than CVP and SVV.

Acute exacerbation of idiopathic pulmonary fibrosis: usual interstitial pneumonitis vs. possible usual interstitial pneumonitis pattern.

BACKGROUND: The prognosis of acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is very poor with a high mortality. The aim of this study was to describe the clinical features and survival of patients with AE-IPF with usual pulmonary fibrosis (UIP) and possible UIP (P-UIP) pattern on chest high resolution computed tomography (HRCT). METHODS: This retrospective study included 107 patients with AE-IPF admitted to Nanjing Drum Tower Hospital from January 2010 to December 2016. The subjects were divided into UIP (n = 86) and P-UIP group (n = 21) based on chest HRCT. Continuous variables were analyzed using Student's t test or Mann-Whitney U test. Categorical variables were analyzed using χ test. Log-rank test was used for the survival analysis. Cox proportional models evaluated the risk factors for AE occurrence and survival. RESULTS: The male, older patients, previous N-acetylcysteine use, elevated white blood cell (WBC) counts, and microbiology infection were more common in the UIP group than the P-UIP group (χ = 13.567, P < 0.001; z = -2.936, P = 0.003; χ = 5.901, P = 0.015; t = 2.048, P = 0.043; χ = 10.297, P = 0.036, respectively). The percentage of AE with UIP pattern in idiopathic interstitial pneumonia (IIP) was significantly higher than P-UIP pattern (χ = 40.011, P < 0.001). Smoking was the risk factor for AE within 6 months after IPF diagnosis in the UIP group. The cumulative proportion survival of 30-days was significantly higher in the UIP group compared with the P-UIP group (χ = 5.489, P = 0.019) despite of the similar overall survival in the two groups. Multivariate Cox regression analysis indicated WBC count, partial pressure of oxygen in artery (PaO2)/fractional concentration of inspired oxygen (FiO2), and computed tomography (CT) score were the independent predictors for survival in the UIP group (hazard ratio [HR]: 1.070, 95% confidential interval [CI]: 1.027-1.114, P = 0.001; HR: 0.992, 95% CI: 0.986-0.997, P = 0.002; and HR: 1.649, 95% CI: 1.253-2.171, P < 0.001, respectively). CONCLUSIONS: AE occurrence of UIP patients in IIP was significantly more than P-UIP cases. The short-term survival was better in the UIP group despite of the similar overall survival in the two groups. WBC count, PaO2/FiO2, and CT score were the independent predictors for survival in UIP subjects.

Effect of early goal directed therapy on tissue perfusion in patients with septic shock.

BACKGROUND: This study aimed to observe the effect of early goal directed therapy (EGDT) on tissue perfusion, microcirculation and tissue oxygenation in patients with septic shock. METHODS: Patients with early septic shock (<24 hours) who had been admitted to the ICU of Zhongda Hospital Affiliated to Southeast University from September 2009 through May 2011 were enrolled (research time: 12 months), and they didn't meet the criteria of EGDT. Patients who had one of the following were excluded: stroke, brain injury, other types of shock, severe heart failure, acute myocardial infarction, age below 18 years, pregnancy, end-stage disease, cardiac arrest, extensive burns, oral bleeding, difficulty in opening the mouth, and the onset of septic shock beyond 24 hours. Patients treated with the standard protocol of EGDT were included. Transcutaneous pressure of oxygen and carbon dioxide (PtcO2, PtcCO2) were monitored and hemodynamic measurements were obtained. Side-stream dark field (SDF) imaging device was applied to obtain sublingual microcirculation. Hemodynamics, tissue oxygen, and sublingual microcirculation were compared before and after EGDT. If the variable meets the normal distribution, Student's t test was applied. Otherwise, Wilcoxon's rank-sum test was used. Correlation between variables was analyzed with Pearson's product-moment correlation coefficient method. RESULTS: Twenty patients were involved, but one patient wasn't analyzed because he didn't meet the EGDT criteria. PtcO2 and PtcCO2 were monitored in 19 patients, of whom sublingual microcirculation was obtained. After EGDT, PtcO2 increased from 62.7±24.0 mmHg to 78.0±30.9 mmHg (P<0.05) and tissue oxygenation index (PtcO2/FiO2) was 110.7±60.4 mmHg before EGDT and 141.6±78.2 mmHg after EGDT (P<0.05). The difference between PtcCO2 and PCO2 decreased significantly after EGDT (P<0.05). The density of perfused small vessels (PPV) and microcirculatory flow index of small vessels (MFI) tended to increase, but there were no significant differences between them (P>0.05). PtcO2, PtcO2/FiO2, and PtcCO2 were not linearly related to central venous saturation, lactate, oxygen delivery, and oxygen consumption (P>0.05). CONCLUSION: Peripheral perfusion was improved after EGDT in patients with septic shock, and it was not exactly reflected by the index of systemic perfusion.