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Liquid chromatography-high-resolution mass spectrometry (LC-HRMS) is the most popular platform for untargeted metabolomics studies, but compound annotation is a challenge. In this work, we developed a new LC-HRMS data-targeted extraction method called MetEx for metabolite annotation. MetEx contains the retention time (

Table S1. Clinical information of enrolled subjects for discovery; Table S2. Clinical information of enrolled hepatic carcinoma subjects for validation; TableS3. Differential metabolites obtained from tissue specimens in metabolomics discovery; Figure S1. Scheme of the metabolic characterization study of hepatic carcinoma; Figure S2. Metabolic pathway analysis for HCC. Figure S3. Refining of important differential metabolites; Figure S4. The correlation between hydroxyproline and clinical parameters for discovery specimens; Figure S5. Proliferation assay in tumor xenografts; Figure S6. mRNA levels of PRODH2 and ALDH18A1 in HCC under hypoxia; Figure S7. 13C5 glutamine tracer analysis for glutamate and proline production under hypoxic condition in SMMC-7721 cell line. (mean± SE); Figure S8. Knockdown of MYC has no effect on expression of prolidase in HCC cell; Figure S9. Knockdown of ALDH18A1 induced apoptosis in the presence of sorafenib under hypoxia.

Purpose: Metabolic reprogramming is frequently identified in hepatocellular carcinoma (HCC), which is the most common type of liver malignancy. The reprogrammed cellular metabolisms promote tumor cell survival, proliferation, angiogenesis, and metastasis. However, the mechanisms of this process remain unclear in HCC.Experimental Design: The global nontargeted metabolic study in 69 paired hepatic carcinomas and adjacent tissue specimens was performed using capillary electrophoresis-time of flight mass spectrometry–based approach. Key findings were validated by targeted metabolomic approach. Biological studies were also performed to investigate the role of proline biosynthesis in HCC pathogenesis.Results: Proline metabolism was markedly changed in HCC tumor tissue, characterized with accelerated consumption of proline and accumulation of hydroxyproline, which significantly correlated with α-fetoprotein levels and poor prognosis in HCC. In addition, we found that hydroxyproline promoted hypoxia- and HIF-dependent phenotype in HCC. Moreover, we demonstrated that hypoxia activated proline biosynthesis via upregulation of ALDH18A1, subsequently leading to accumulation of hydroxyproline via attenuated PRODH2 activity. More importantly, we showed that glutamine, proline, and hydroxyproline metabolic axis supported HCC cell survival through modulating HIF1α stability in response to hypoxia. Finally, inhibition of proline biosynthesis significantly enhanced cytotoxicity of sorafenib in vitro and in vivo.Conclusions: Our results demonstrate that hypoxic microenvironment activates proline metabolism, resulting in accumulation of hydroxyproline that promotes HCC tumor progression and sorafenib resistance through modulating HIF1α. These findings provide the proof of concept for targeting proline metabolism as a potential therapeutic strategy for HCC. Clin Cancer Res; 24(2); 474–85. ©2017 AACR.

BACKGROUND Dipeptidyl peptidase-4 (DPP4) is associated with cognitive dysfunction in patients with type 2 diabetes. AIM To assess a possible relationship between serum DPP4 and cognitive function in perinatal pregnant women with gestational diabetes mellitus (GDM). METHODS The study subjects were divided into three groups: GDM group (n = 81), healthy pregnant (HP) group (n = 85), and control group (n = 51). The Montreal Cognitive Assessment (MoCA) was used to assess the cognitive status of each group. Venous blood samples were collected to measure blood lipids, glycated hemoglobin, and glucose levels. For each participant, a 3-mL blood sample was collected and centrifuged, and the serum was collected. Blood samples were stored at -80 ℃, and DPP4, interleukin-6 (IL-6), and 8-iso-prostaglandin F2α (8-iso-PGF2α), and brain-derived neurotrophic factor (BDNF) were detected using ELISA. RESULTS The MoCA scores in the GDM and HP groups were significantly different from those in the control group in terms of visuospatial/executive function and attention (P < 0.05); however, the scores were not significantly different between the GDM and HP groups (P > 0.05). In terms of language, the GDM group had significantly different scores from those in the other two groups (P < 0.05). In terms of memory, a significant difference was found between the HP and control groups (P < 0.05), as well as between the GDM and HP groups. The levels of DPP4, IL-6, and 8-iso-PGF2α in the GDM group were significantly higher than those in the HP and control groups (P < 0.05); however, the differences between these levels in the HP and control groups were not significant (P > 0.05). The level of BDNF in the GDM group was significantly lower than that in the HP and control groups (P < 0.05), although the difference in this level between the HP and control groups was not significant (P > 0.05). CONCLUSION Cognitive dysfunction in perinatal pregnant women with GDM mainly manifested as memory loss, which might be associated with elevated DPP4 levels.

Rapid and quantitative determination of blood propofol concentration is important for anesthesiologists to accurately control intraoperative propofol dose, timely monitor physiological statuses of patients and greatly improve the safety of surgery. Herein, a dopant-assisted negative photoionization ion mobility spectrometer with the optimized ionization region structure and the three-way inlet design was developed, increasing the generation ratio of the reactant ions O2−, and improving the ionization efficiency of propofol molecules. Besides, the addition of methanol-anisole solution during injection promoted the neutral desorption of propofol in blood, further improving the detection sensitivity by an order of magnitude, eliminating any sample pretreatment and effectively reducing the single analysis time to less than 1 min compared to the previous article. The dual calibration quantitative method, i.e. the method of calibrating the O2− concentration and the sample concentration changes during the entire process of detecting propofol through the integral value of M·O2− and the maximum signal intensity of O2−, successfully achieved accurate quantification of blood propofol. And the linear calibration curve of propofol was obtained with the range of 0.1–15 ng μL−1 and with the limit of detection of 0.03 ng μL−1, which was fulfilled to conduct propofol determination throughout the perioperative period. Finally, this method was applied to clinically measure the blood propofol concentration in patients newly regained consciousness with concentrations ranging from 0.2 ng μL−1 to 3 ng μL−1, and it turned out that the older patient had the lower propofol concentration in blood.

In order to study anesthetic pharmacokinetics and adequately adjust the anaesthesia depth of patients, real-time measurement of the intraoperative exhaled propofol concentration is of significant importance for anaesthetists. Although a series of analytical techniques and methods have been developed for the detection of exhaled propofol, differential mobility spectrometry (DMS) with the advantages of a much smaller instrument, faster response time and cheaper cost shows great potential for the point of care in the operating room. In this paper, a planar DMS was constructed for real-time continuous measurement of trace propofol in exhaled air. The effects of DMS parameters, such as the radio frequency voltage, the drift gas flow rate and the sampling flow rate of exhaled air on the propofol measurement under high humidity conditions were carefully investigated and discussed. Under the optimum experimental conditions, the limit of detection (LOD) for propofol was achieved in ppbv with a linear range of 0.5 to 25 ppbv, both of which meet clinical requirements. Finally, the planar DMS was performed on a patient undergoing thyroidectomy surgery to real-time monitor the intraoperative exhaled propofol, which demonstrated the capability of DMS for sensitive and breath-by-breath continuous measurement of intraoperative trace exhaled propofol.

Purpose. To explore whether pregnant women with gestational diabetes mellitus (GDM) had cognitive impairment and assess cognitive function in normal pregnant women. Methods. A total of 75 consecutive women diagnosed with GDM (GDM group), 70 normal pregnant women (NP group) without diabetes and matched for age, and 51 female volunteers (CG group) with the similar age level, normal blood glucose, and nonpregnancy were included in the study. For the assessment of cognitive functions, Montreal Cognitive Assessment (MoCA) was performed. Venous blood samples were collected to measure blood glucose, glycated hemoglobin (HbA1c), methylglyoxal (MGO), beta amyloid (Aβ), and tau protein. Results. The score of MoCA of GDM was lowest, and the score of the NP group was lower than volunteers ( P < 0.05 ). The incidence of cognitive dysfunction increased significantly in the GDM group with statistical significance ( P < 0.05 ). The levels of tau and MGO in the GDM group were significantly less than those in the NP and CG groups, and Aβ in the GDM group was significantly more than that in the NP and CG groups ( P < 0.05 ), but the differences between NP and CG groups were not statistically significant ( P < 0.05 ). Conclusion. The pregnant women with GDM showed a significant decline in cognitive function, and the normal pregnant women also showed a decline in cognitive function which is very light.

Background It has proved that there is an association between cancer and volatile organic compounds (VOCs) of exhaled breath. This study targets on verifying the existence of specific VOCs in breathing in breast cancer patients, especially those with ductal carcinoma in situ (DCIS). Methods There were a total of 203 participants included in the final analysis, which included 71 (35.0%) patients with histologically confirmed breast cancer (including 13 with DCIS, 31 with lymph node metastasis‐negative status, and 27 with lymph node metastasis‐positive status), 78 (38.4%) healthy volunteers, and 54 (26.6%) patients with histologically confirmed gastric cancer. Gas chromatography‐mass spectrometry and solid‐phase microextraction were used to analyze the breath samples for the presence of VOCs. Results There were significant differences in the volatile organic metabolites between the DCIS, lymph node metastasis‐negative breast cancer, and lymph node metastasis‐positive breast cancer groups compared with the healthy controls as well as between the breast cancer and gastric cancer patients. An overlapping set of seven VOCs, including (S)‐1,2‐propanediol, cyclopentanone, ethylene carbonate, 3‐methoxy‐1,2‐propanediol, 3‐methylpyridine, phenol, and tetramethylsilane, was significantly different between the breast cancer patients and healthy individuals as well as between the breast cancer and gastric cancer patients. The combination of these seven compounds was considered as a biomarker for breast cancer. The sensitivity for predicting DCIS by this set of seven compounds was determined to be 80.77%, and the specificity was determined to be 100%. Conclusions This set of seven breast cancer‐specific VOCs can be regarded as one particular expiratory marker for DCIS and will help to establish new screening methods for early breast cancer., Exhaled breath analysis using Gas Chromatography–Mass Spectrometry (GC/MS) can distinguish patients with breast cancer in situ from healthy people. And seven VOCs can be served as biomarkers, They are (S)‐1,2‐propanediol, Cyclopentanone, Ethylene carbonate, 3‐Methoxy‐1,2‐propanediol, 3‐Methylpyridine, phenol, and Tetramethylsilicane. The sensitivity for predicting DCIS by this seven compounds model is 80.77%.

Unclarified molecular mechanism and lack of practical diagnosis biomarkers hinder the effective treatment of non-small-cell lung cancer. Herein, we performed liquid chromatography-mass spectrometry-based nontargeted metabolomics analysis in 131 patients with their lung tissue pairs to study the metabolic characteristics and disordered metabolic pathways in lung tumor. A total of 339 metabolites were identified in metabolic profiling. Also, 241 differential metabolites were found between lung carcinoma tissues (LCTs) and paired distal noncancerous tissues; amino acids, purine metabolites, fatty acids, phospholipids, and most of lysophospholipids significantly increased in LCTs, while 3-phosphoglyceric acid, phosphoenolpyruvate, 6-phosphogluconate, and citrate decreased. Additionally, pathway enrichment analysis revealed that energy, purine, amino acid, lipid, and glutathione metabolism are markedly disturbed in lung cancer (LCa). Using binary logistic regression, we further defined candidate biomarkers for different subtypes of lung tumor. Xanthine and PC 35:2 were selected as combinational biomarkers for distinguishing benign from malignant lung tumors with a 0.886 area under curve (AUC) value, and creatine, myoinositol and LPE 16:0 were defined as combinational biomarkers for discriminating adenocarcinoma from squamous cell lung carcinoma with a 0.934 AUC value. Overall, metabolic characterization and pathway disturbance demonstrated apparent metabolic reprogramming in LCa. The defined candidate metabolite marker panels are useful for subtyping of lung tumors to assist clinical diagnosis.

We aimed to investigate the role and mechanism of sevoflurane (SEV) preconditioning in liver ischemia-reperfusion (I/R) injury. In vivo, rats were randomly divided into Sham group, I/R rat model group, I/R + SEV group and SEV group. In vitro, hypoxia-reoxygenation (H/R) cell model were established. Hematoxylin-Eosin (H&E) and TUNEL assay were used to evaluate the degree of tissue damage and detect apoptosis in rats, respectively. HO-1, nuclear Nrf2 and cytosolic Nrf2 expressions were detected by immunohistochemical staining, Western blot analysis and quantitative real-time PCR (qRT-PCR), respectively. Contents of Lactate dehydrogenase (LDH), malondialdehyde (MDA), and reactive oxygen species (ROS) were determined by corresponding kits. Inflammatory factor levels, cell viability, apoptosis were detected by enzyme-linked immunosorbent assay (ELISA), MTT assay, and flow cytometry, respectively.In the I/R group, liver damage was severe, apoptosis-positive cells were increased, HO-1 and nuclear Nrf2 expressions were increased, and cytosolic Nrf2 expression was decreased. After SEV pretreatment, the degree of liver injury and apoptosis in rats were significantly reduced, HO-1 and nuclear Nrf2 expressions were increased significantly, and cytosolic Nrf2 expression was decreased. 4% SEV had the best mitigating effect on H/R-induced liver cell damage, as evidenced by reduced contents of LDH and MDA, decreased inflammatory factors, a lowered apoptosis rate, inhibited ROS production, effectively promoted Nrf2 nucleation, and activated Nrf/HO-1 pathway. ML385 pretreatment significantly inhibited the effect of SEV on hepatocytes.Sevoflurane protects the liver from ischemia-reperfusion injury by regulating the Nrf2/HO-1 pathway.

// Jian He 1, * , Mingju Sun 1, * , Enyou Li 2, * , Yingyong Hou 5, * , Matthew J. Shepard 3, 6 , Di Chen 1 , Karel Pacak 7 , Changsong Wang 4 , Lei Guo 2 , Zhengping Zhuang 3 and Yang Liu 1 1 Scientific Research Center for Translational Medicine, Department of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China 2 Department of Anesthesiology, First Affiliated Hospital of Harbin Medical University, Harbin, China 3 Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 4 Department of Critical Care Medicine, The Third Affiliated Hospital of Harbin Medical University, Nangang District, Harbin, China 5 Department of Pathology, School of Basic Medical Sciences & Zhongshan Hospital, Fudan University, Shanghai, China 6 Department of Neurologic Surgery, University of Virginia Health System, Charlottesville, Virginia, USA 7 Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA * These authors have contributed equally to this work Correspondence to: Zhengping Zhuang, email: zhuangp@ninds.nih.gov Yang Liu, email: yliuqq@dicp.ac.cn Keywords: cardiac myxomas; PRKAR1A; somatic mutation Received: July 14, 2017 Accepted: September 20, 2017 Published: October 19, 2017 ABSTRACT Background: Cardiac myxomas are benign tumors that commonly arise within the left atria. Familial cardiac myxomas are a part of Carney Complex (CNC), an autosomal dominant multiple neoplasia syndrome caused by germline mutations in PRKAR1A . Seven percent of cardiac myxomas are associated with CNC. To date, the genetic basis of isolated cardiac myxomas (ICM), however, has not been fully elucidated. Methods: We investigated the genetic profile of ICM using whole exome sequencing (WES). Suspected mutations were confirmed using targeted sanger sequencing. To further examine the presence of PRKAR1A mutations in ICM, we performed targeted sequencing in an additional 61 ICM specimens. Results: 87.5% (7/8) of ICM harbored mutations in PRKAR1A . Three of the 8 ICM harbored biallelic somatic mutations of PRKAR1A , including c.607_610del:p.Leu203fs (pathogenic) + c.C896G:p.Ser299X (pathogenic), c.952delT:p.Leu318fs (pathogenic) + c.769-2 A>G (pathogenic) and c.178-1 G>C (pathogenic) + c. 550+1 G>C (pathogenic). Four of 8 tumors harbored monoallelic PRKAR1A mutations, including c.523_524insG:p.Tyr175_Val176delinsX (pathogenic), c.C920A:p.Ser307X (pathogenic), c.30delG:p.Glu10fs (pathogenic) and c.C289T:p.Arg97X (pathogenic). No identical variants were observed across the 8 ICM samples. Interestingly, none of these variants have been previously described in familial cardiac myxomas. In order to confirm our findings, directed sequencing of 61 ICM specimens was subsequently performed. Sixty-four percent (39/61) of ICMs tumors contained inactivating PRKAR1A mutations. Conclusion: Our findings suggest that loss-of-function mutations of PRKAR1A may play a vital role in the formation of isolated cardiac myxomas.

As the number of elderly patients increases, some patients with heart problems may also need surgery. The purpose of this study was to investigate whether dexmedetomidine (DEX), a common used anesthetic, was beneficial to the patients with heart problems. Myocardial cells induced by doxorubicin (DOX) was to simulate the myocardium injury in vitro. H9c2 cells were treated with DOX, DEX/DOX, Compound C and Compound C/DEX/DOX, respectively. The expression of p-AMPK, AMPK, p-GSK3β, GSK3β, Bcl2, Bax, Cleaved caspase3, Caspase3, TXNIP, NLRP3, ASC, Cleaved caspase-1 and Caspase-1 were analyzed by Western blot. CCK-8 assay and flow cytometry analysis were used to detect the cell viability and cell apoptosis. The levels of TNF-α, IL-1β and IL-18 were detected by ELISA assay and the levels of NO, ROS, LDH, SOD, MDA and taurine were detected by corresponding assay kits. As a result, DEX promoted the cell viability and inhibited the inflammation, oxidative stress and apoptosis. In addition, DEX suppressed the expression of taurine, TXNIP, NLRP3, ASC and cleaved caspase-1 and activated the expression of p-AMPK and p-GSK3β. However, those above changes could be reversed by Compound C. In conclusion, this study indicated that DEX could reduce the inflammation and apoptosis of DOX-induced myocardial cells through activating the AMPK-GSK3β signaling pathway. Because of the above effects of DEX, it may be beneficial for surgical patients with heart problems.

The concentration of propofol in blood is an important indicator for anesthesiologists to monitor and regulate the anesthesia depth of patients during surgery. Herein, a negative photoionization ion mobility spectrometry with acetone as the dopant was developed for rapid and direct determination of intraoperative blood propofol concentration in the operating theatre. High concentration of acetone molecules in the carrier gas was used not only to enhance neutral desorption and release free propofol molecules from the whole blood, but also to increase the intensity of reactant O2− and reduce the amount of non-reactive CO3− ions simultaneously, which allowed to measure trace propofol in less than 2 min without any tedious pretreatment. Under optimized conditions, a linear calibration curve of propofol was obtained with the range of 0.5–20 ng μL−1 and with a limit of detection of 0.14 ng μL−1, which met the clinical requirements and correlated well with standard HPLC methods. Finally, the method was applied to detect intraoperative blood propofol concentration in nearly 100 surgical patients, demonstrating its excellent detection capability and facilitating the study of propofol pharmacokinetics.

Background: Central nervous system (CNS) infectious diseases are common diseases in emergency rooms and neurology departments. CNS pathogen identification methods are time consuming and expensive and have low sensitivity and poor specificity. Some studies have shown that bacteria and viruses can produce specific volatile organic compounds (VOCs). The aim of this study is to find potential biomarkers by VOC analysis of cerebrospinal fluid (CSF) in patients with bacterial and viral meningitis/encephalitis (ME). Methods: CSF samples from 16 patients with bacterial ME and 42 patients with viral ME were collected, and solid-phase microextraction combined with gas chromatography-mass spectrometry was used to analyze the metabolites in the CSF. Results: There are 2 substances (ethylene oxide and phenol) that were found to be different between the 2 groups. Ethylene oxide was significantly greater in the group of bacterial ME patients than in the viral ME group of patients (p < 0.05). In addition, phenol was remarkably increased in the group of ME patients compared with the bacterial ME patients (p < 0.05). Conclusions: Ethylene oxide and phenol may be potential biomarkers to distinguish bacterial ME and viral ME. VOC analysis of CSF may be used as a supporting tool for clinical diagnosis.

Background: Volatile organic compound (VOC) analysis provides an elegant approach for colorectal cancer screening. An organic compound with a high vapor pressure or volatility can be detected in the headspace of cancer cells or blood samples. Therefore, analyzing VOCs in the blood of rats inoculated with colorectal cancer tissue and in SW480 medium from cultured colorectal cancer cells may provide accurate results. Methods: After collecting venous blood from rats inoculated with cancer cells at different times, the cancer tissue was removed from the inoculated rats, and the medium was harvested from the cancer cells and cultured in the presence or absence of a chemotherapy drug of intestinal epithelial cells. We used solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) to analyze the headspace of the blood and media to evaluate the VOC profiles. Statistical analysis was conducted using principal component analysis (PCA) and orthogonal partial least-squares analysis (OP-LSDA). Results: The in vivo and in vitro analyses of the colorectal cancer samples revealed a variety of compounds, such as cyclohexanone, 1-hexanol, 2-ethyl-, butylated hydroxytoluene, cyclotrisiloxane, hexamethyl-, pentanoic acid, 2,2,4-trimethyl-3-hydroxy-isobutyl ester and acetone. Butylated hydroxytoluene is unique with regard to its presence during tumor growth and resection; it is also present during tumor cell growth and necrosis. Acetone showed unique trends in the in vivo experimental group. Conclusions: By analyzing VOC fingerprints related to colorectal cancer (CRC), we found that butylated hydroxytoluene and acetone have unique signatures that may provide the basis for clinical diagnosis and disease assessment.

Background: Although significant advances have been made toward understanding the molecular mechanisms underlying the effect of propofol on tumor cell metastasis, less is known regarding how cell membrane and cytoskeletal ultrastructure are affected in this process. Here, we investigated the relationship between cell morphology and cell size, which are features mainly defined by the cytoskeleton. Methods: To confirm the effects of propofol on the migratory ability of human cervical carcinoma cells, cell migration and invasion were examined through scratch wound healing and transwell membrane assays. Furthermore, HeLa cells cultivated with different concentrations of propofol were examined by confocal microscopy and atomic force microscopy (AFM), and the mean optical density and migration ability of these cells were also assessed. In addition, cell membrane morphology was inspected using AFM. Results: The results of the wound healing and transwell membrane assays indicated that propofol decreases the migratory ability of cervical carcinoma cells compared to control cells. A comparative analysis of the test results revealed that short-term (3 h) exposure to propofol induced marked changes in cell membrane microstructure and in the cytoskeleton in a dose-dependent manner. These morphological changes in the cell membrane were accompanied by cytoskeleton (F-actin) derangement. The present findings demonstrate a close relationship between changes in cell membrane ultrastructure and cytoskeletal alterations (F-actin) in propofol-treated HeLa cells. AFM scanning analysis showed that cell membrane ultrastructure was significantly changed, including a clear reduction in membrane roughness. Conclusion: The influence of propofol on the HeLa cell cytoskeleton can be directly reflected by changes in cellular morphology, as assessed by AFM. Moreover, the use of AFM is a good method for investigating propofol-mediated changes within cytoskeletal ultrastructure.

Online measuring end-tidal propofol concentration during balanced anesthesia is important for anesthetists to learn the patient's anesthesia depth as exhaled propofol concentration is well related to blood propofol concentration. In previous work, exhaled propofol was detected using acetone assisted negative photoionization ion mobility spectrometer, however, the existence of high concentration sevoflurane interfered the response of propofol. In this work, an anisole assisted photoionization ion mobility spectrometer operated in positive mode was developed to sensitively and selectively measure the end-tidal propofol by eliminating the interferences of exhaled humidity and sevoflurane during balanced anesthesia. Anisole molecular ion is stable enough not to go under proton transfer reaction with water presents in the exhaled breath. Hence, the exhaled humidity related peaks were eliminated and only one propofol product ion peak (K0 = 1.50 cm2 V−1 s−1) was observed. The relative standard deviation (RSD) ranging from 0.64%–0.91% showed good repeatability and the quantitative range was 0.2–40 ppbv with a response time of 4 s. Finally, the performance of the proposed method was demonstrated by monitoring end-tidal propofol of balanced anesthetized patients during gastric cancer surgery.

Online monitoring of end-tidal propofol provides important information of anesthesia deepness for anesthetists as propofol concentrations in plasma and breath are well correlated. In this work, a dopant-assisted photoionization positive ion mobility spectrometry (DAPI-PIMS) coupled with time-resolved purge introduction was developed for online quantitative monitoring end-tidal propofol. With optimized dopant, toluene, the selectivity and sensitivity of propofol was improved as interference from sevoflurane was eliminated. Using the time-resolved purge introduction, the response of propofol and moisture was separated due to their absorption differences on the inwall of the fluorinated ethylene propylene (FEP) sample loop, ensuring sensitive measurement of end-tidal propofol with a short response time of 4 s. The quantitative equation derived from the second order reaction kinetics model extended the quantitative range of propofol from 0.2 ppbv to 45 ppbv. Finally, the method was used to monitor the intraoperative end-tidal propofol of six patients, and the results nicely demonstrated its feasibility in practical clinical environment.

Online monitoring of exhaled propofol concentration is important for anesthetists to provide adequate anesthesia as propofol concentrations in plasma and breath are correlated reasonably well. Exhaled propofol could be detected by 63Ni ion mobility spectrometry in negative ion mode; however, the radioactivity of 63Ni source restricts its clinical application due to safety, environmental, and regulatory concerns. An acetone-assisted negative photoionization ion mobility spectrometer (AANP-IMS) using a side-mounted vacuum ultraviolet (VUV) lamp in the unidirectional (UD) flow mode was developed for sensitive measurement of exhaled propofol by producing a high percentage of O2-(H2O) n. An adsorption sampling and time-resolved purge introduction system was developed to eliminate the interference of residual inhaled anesthetic sevoflurane based on their different adsorptions between propofol and sevoflurane on the inwall of the fluorinated ethylene propylene (FEP) sample loop. The effects of the inner diameter and the length of the sample loop on the signal intensity of propofol and the time-resolution between propofol and sevoflurane were theoretically and experimentally investigated. A sample loop with 3 mm i.d. and 150 cm length allowed sensitive measurement of exhaled propofol with a response time of 4 s, a linear response range for propofol was achieved to be 0.2 to 14 ppbv with a limit of detection (LOD) of 60 pptv, and the quantification of propofol was not influenced by the change of the sevoflurane concentration. Finally, the performance of monitoring exhaled propofol during surgery was demonstrated on a patient undergoing laparoscopic distal pancreatectomy combined with cholecystectomy.

Background: Volatile organic compound (VOC) analysis provides an elegant approach for colorectal cancer screening. Many studies have focused on the relationship between VOCs in exhaled breath and cancer. However, many factors can affect the presence of VOCs in exhaled breath, such as smoking and diet. An organic compound with a higher vapor pressure or volatility can be detected in the headspace of cancer cells or blood samples. Therefore, analyzing VOCs in the blood of rats inoculated with colorectal cancer tissue and in SW480 medium from cultured colorectal cancer cells provides more accurate results. Methods: After collecting venous blood from rats inoculated with cancer cells at different times, removing cancer tissue from the inoculated rats, and harvesting the medium of cancer cells cultured in the presence or absence of chemotherapy drug and of intestinal epithelial cells, we used solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) to analyze the headspace of the blood and media to evaluate the VOC profiles. Statistical analysis was conducted using principal component analysis (PCA) and orthogonal partial least squares(OP-LSDA). Findings: In the in vivo and in vitro analyses of the colorectal cancer samples, we found a variety of compounds, such as cyclohexanone; 1-hexanol, 2-ethyl-; butylated hydroxytoluene; cyclotrisiloxane, hexamethyl-; pentanoic acid, 2,2,4-trimethyl-3-hydroxy-isobutyl ester; and acetone. Among these compounds, butylated hydroxytoluene is unique with regard to its presence during the processes of tumor growth and resection; it is also present during the processes of tumor cell growth and necrosis. Acetone showed unique trends in the in vivo experimental group. Interpretation: By analyzing VOC fingerprints relating to CRC, we found that butylated hydroxytoluene and acetone have unique signatures that may provide the basis for clinical diagnosis and disease assessment. Funding Statement: The project is funded by the National Natural Science Foundation of China (No. 81402462); Nn10 program and Distinguished Young Scholars Fund of Harbin Medical University Cancer Hospital; The Yuweihan Fund for Distinguished Young Scholars of Harbin Medical University; Harbin Science and Technology Innovation Scholars Fund (2017RAXXJ087); Heilongjiang Province Postdoctoral Research Fund. Declaration of Interest: The authors declare no potential conflicts of interest. Ethics Approval Statement: This study’s protocol was approved by the Ethics Committee at the First Affiliated Hospital of Harbin Medical University (No.2017005).

Urinary volatile organic compounds (VOCs) profiling has recently received considerable attention because it can be obtained noninvasively and conveniently while it can be successfully used in a variety of diseases and can provide unique biomarkers. The aim of current study was to investigate potential biomarkers between minimal change type nephrotic syndrome (MCNS) and normal. Urinary samples were collected from 38 minimal change type nephrotic syndrome patients and 15 healthy controls. Solid phase microextraction (SPME) and chromatography- mass spectrometry (GC-MS) were used to analysis the urinary metabolites. To deal with the final data, the statistical methods principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLSDA) were performed. Six specific VOC biomarkers were present at abnormal levels in the urine of MCNS patients. These VOCs included trans-2,2-dimethyl-4-decene; pyrrole; carbamic acid, monoammonium salt; 1-butyne, 3,3-dimethyl-; diisopropylamine; and 4-heptanone. These biomarkers may be useful as a new diagnostic method and for monitoring the prognosis for MCNS patients.

Compared with other types of cancer, thyroid cancer incidence rates have increased rapidly worldwide in the past few decades. In recent years, potential thyroid cancer biomarkers have been studied, but these biomarkers have neither specificity nor good positive predictive value. Exhaled breath analysis is a recently developed convenient and noninvasive method for screening and diagnosing the disease. In this study, potential thyroid cancer biomarkers in volatile organic compounds (VOCs) were detected. Exhaled breath was collected from 64 patients with histologically confirmed cases of thyroid disease (including 39 individuals with papillary thyroid carcinoma and 25 individuals with nodular goiters) and 32 healthy volunteers. Solid-phase microextraction-gas chromatography and mass spectrometry was used to assess the exhaled VOCs of the study participants. The statistical methods of principal component analysis and partial least-squares discriminant analysis were performed to process the final data. The VOCs exhibited significant differences between nodular goiter patients and normal controls, papillary thyroid carcinoma patients and normal controls, and papillary thyroid carcinoma patients and nodular goiter patients; 7, 7, and 3 characteristic metabolites played decisive roles in sample classification, respectively. Breath analysis may provide a new, noninvasive, and directly qualitative method for the clinical diagnosis of thyroid disease.

The prevalence of obesity has dramatically increased and poses a major threat to human health. Obesity often accompanies hyperlipemia, which is strongly related to the occurrence and development of obesity-related chronic diseases. Differences in metabolomic profiling of serum between obese (with hyperlipemia) and normal-weight men (n = 30 in each group) were investigated using ultrahigh-pressure liquid chromatography-quadrupole-time of flight mass spectrometry (UHPLC-Q-TOF MS/MS) and partial least-squares-discriminant analysis (PLS-DA). Obese men showed higher levels of weight, body mass index, fat mass, systolic blood pressure, fasting plasma glucose, triglyeride, total cholesterol, insulin, HOMA-IR and high-sensitivity CRP. Obese and normal-weight groups were clearly discriminated from each other on a PLS-DA score plot and nine major metabolites contributing to the discrimination were assigned, including increased 2-octenoylcarnitine, eicosadienoic acid, 12-hydroperoxyeicosatetraenoic acid, 4-hydroxyestrone sulfate, lysoPE[18:1(11Z)/0:0], thromboxane B2 and pyridinoline and decreased vitamin D3 glucosiduronate and 9,10-DHOME. These metabolites were associated with lipid metabolism and obesity-related diseases, and reflected the metabolic differences between normal and obese men, which may be important for future clinical diagnosis, treatment and assessment of the therapeutic effect on obesity-related chronic disease.

Background Breath analysis of propofol is a potential noninvasive method for approximating the plasma propofol concentration. There have been various reported techniques for measuring the exhaled propofol concentration at steady state; however, the propofol concentration undergoes marked changes during clinical anesthesia. Therefore, this study investigated the use of membrane inlet-ion mobility spectrometry (MI-IMS) to monitor exhaled propofol discontinuously and continuously during propofol anesthesia. Methods The study included 19 patients of American Society of Anesthesiologists physical status I or II. In experiment I (discontinuous study), breath and blood samples were collected discontinuously, with stable target propofol concentrations of 2.8 μg/ml, 3.2 μg/ml, 3.5 μg/ml, and 3.8 μg/ml. In experiment II (continuous study), propofol concentration was maintained at 3.5 μg/ml after induction, and exhaled breath was collected continuously every 3 min during propofol infusion. Relationships of the exhaled propofol concentration with the plasma propofol concentration, measured by high-performance liquid chromatography and the continuously measured bispectral (BIS) index were investigated. Results Comparison of the exhaled and plasma propofol concentrations revealed a bias ± precision of 2.1% ± 14.6% (95% limits of agreement: − 26.5–30.7%) in experiment I and − 10.4% ± 13.2 (− 36.3–15.4%) in experiment II. In both experiments, exhaled propofol concentrations measured by MI-IMS were consistent with, the propofol effect represented by the BIS index. Conclusions MI-IMS may be a suitable method to predict plasma propofol concentration online during propofol anesthesia. Monitoring exhaled propofol may improve the safety of propofol anesthesia.

Background Gastric cancer ranks 4th among the most common cancers worldwide, and the mortality caused by gastric cancer is 2nd only to lung cancer. Gastric cancer shows a lack of specific symptoms in its early stages. In addition, its clinical symptoms often do not match the corresponding stage. Upper gastrointestinal endoscopy with biopsy is the gold standard for the diagnosis of gastric cancer because of its high accuracy. However, this operation is invasive, patient compliance is poor, and high demands for medical staff and equipment are typical of this procedure. Recent studies have demonstrated a connection between specific breath volatile organic compounds (VOCs) and various forms of cancers. Methods We collected expired air from patients with gastric cancer, chronic atrophic gastritis or gastric ulcers as well as from healthy individuals. Solid-phase microextraction, gas chromatography–mass spectrometry and principal component analysis statistics were applied to identify potential biomarkers of gastric cancer among VOCs. Results Fourteen differential metabolites were annotated using the NIST 11 database, with a similarity threshold of 70%. Currently, the metabolic origin of VOCs remains unclear; however, several pathways might explain the decreasing or increasing trends that were observed. Conclusions The results of this study demonstrate the existence of specific VOC profiles associated with patients with carcinoma. In addition, these metabolites may contribute to the diagnosis and screening of patients with carcinoma.

Background Cardiac myxomas are benign tumors that commonly arise within the left atria. Familial cardiac myxomas are a part of Carney Complex (CNC), an autosomal dominant multiple neoplasia syndrome caused by germline mutations in PRKAR1A. Seven percent of cardiac myxomas are associated with CNC. To date, the genetic basis of isolated cardiac myxomas (ICM), however, has not been fully elucidated. Methods We investigated the genetic profile of ICM using whole exome sequencing (WES). Suspected mutations were confirmed using targeted sanger sequencing. To further examine the presence of PRKAR1A mutations in ICM, we performed targeted sequencing in an additional 61 ICM specimens. Results 87.5% (7/8) of ICM harbored mutations in PRKAR1A. Three of the 8 ICM harbored biallelic somatic mutations of PRKAR1A, including c.607_610del:p.Leu203fs (pathogenic) + c.C896G:p.Ser299X (pathogenic), c.952delT:p.Leu318fs (pathogenic) + c.769-2 A>G (pathogenic) and c.178-1 G>C (pathogenic) + c. 550+1 G>C (pathogenic). Four of 8 tumors harbored monoallelic PRKAR1A mutations, including c.523_524insG:p.Tyr175_Val176delinsX (pathogenic), c.C920A:p.Ser307X (pathogenic), c.30delG:p.Glu10fs (pathogenic) and c.C289T:p.Arg97X (pathogenic). No identical variants were observed across the 8 ICM samples. Interestingly, none of these variants have been previously described in familial cardiac myxomas. In order to confirm our findings, directed sequencing of 61 ICM specimens was subsequently performed. Sixty-four percent (39/61) of ICMs tumors contained inactivating PRKAR1A mutations. Conclusion Our findings suggest that loss-of-function mutations of PRKAR1A may play a vital role in the formation of isolated cardiac myxomas.

On-line monitoring of propofol in exhaled air is a potential way to evaluate the anaesthesia depth for patients during surgery. In this study, a negative (63)Ni ionization high resolution ion mobility spectrometer with Bradbury-Nielsen-Gate-Grid structure was built to measure propofol with reactant ions Cl(-)(H2O) n using dichloromethane as dopant. Instead of forming three propofol ions (M - H)(-), M · O2(-), and (M2 - H)(-) with reactant ions O2(-)(H2O)n, only product ion M · Cl(-) was produced when introducing dichloromethane gas. The peak-to-peak resolution (R p-p) between reactant ions Cl(-)(H2O)n and product ion M · Cl(-) was 17.4, which was 1.6 times larger than that between O2(-)(H2O)n and product ion. Furthermore, the linear response range using reactant ions Cl(-)(H2O)n was 3.5 times wider than that obtained with reactant ions O2(-)(H2O)n.

Acute lung injury (ALI), acute respiratory distress syndrome (ARDS), is actually involved in an ongoing and uncontrolled inflammatory response in lung tissues. Although extensive studies suggested that phospodiesterase type 4B (PDE4B) may be related to inflammation, the underlying cell biological mechanism of ALI remains unclear. To further investigate the mechanism how PDE4B take part in inflammatory response and the maintenance of vascular integrity, we established the experimental model of ALI in vitro and in vivo. In vitro, we found that Cilomilast, Diazepam and PDE4B knockout could potently inhibit the LPS-induced NF-κB activation and inflammatory response in multiple cell types, including lung epithelial cells (A549), pulmonary microvascular endothelial cells (PMVECs) and vascular smooth muscle cells (VSMCs). Besides, PDE4B deletion attenuated the LPS-induced ROS generation. In vivo, PDE4B deletion could attenuate the lung water content, histological signs of pulmonary injury and elevate the ratio of partial pressure of arterial O2 to fraction of inspired O2 (PaO2/FIO2 ratio). Additionally, PDE4B deletion reduced LPS-induced vascular permeability. Collectively, our results strongly indicates that PDE4B is a valid target for anti-ALI.

Background Pre-emptive analgesia may relieve post-operative pain. However, its effects on immune function of patients undergoing thoracotomy are still unclear. Therefore, we investigated effects of pre-emptive epidural analgesia on post-operative pain and immune function in patients undergoing thoracotomy. Methods Ninety patients undergoing thoracotomy were randomized equally into three groups. Group A (control) only received patient-controlled epidural analgesia (PCEA). Group B (routine) was given 0.125% ropivacaine 6 mL 30 min after surgery, then PCEA. Group C (pre-emptive) received 0.125% ropivacaine 6 mL 30 min before skin incision and every 60 min during surgery, then PCEA. Visual analogue scale scores and cytokine levels were the main outcomes. Secondary outcomes included analgesic demands, side effects and hospital stays. Results Post-operative visual analogue scale scores were decreased in group C compared with group B, and that of group B were lower than in group A (P < 0.05). Compared with group B, protein and mRNA expressions of tumour necrosis factor-α, interleukin (IL)-6 and IL-8 were decreased, and that of IL-4 were increased in group C (P = 0.002∼0.049). Both analgesic demands and the incidences of nausea/vomiting and hypotension were lower in group C compared with group B (P = 0.01∼0.037). Hospital stays were shorter in group C compared with group B (P = 0.045). Conclusions These findings suggest that pre-emptive epidural analgesia can produce better analgesia effects, with less analgesic demands and side effects, and attenuate the surgery-induced immune alterations, and improve the post-operative recovery in patients undergoing thoracotomy.

Monitoring the exhaled propofol concentration is helpful for anaesthetists to ensure the safety of patients and to adjust the anaesthesia depth. In this study, a trap-and-release membrane inlet ion mobility spectrometer (TRMI-IMS) was constructed for on-line measurement of trace propofol in exhaled air. The effects of trap-and-release parameters such as the trap temperature, release temperature and carrier gas flow rate were investigated. Once optimum experimental parameters were identified, the limits of detection (LODs) for propofol at sampling times of 0.5, 1, 2, and 3 min were found to be 17, 8, 3, and 2 pptv, respectively. With a sampling time of 1 min, the response of TRMI-IMS to propofol was enhanced by a factor of 9 as compared with that of constant temperature MI-IMS; the calibration curve resulting from three individual experiments was linear in the range of 0.1 to 2.5 ppbv. Finally, TRMI-IMS was performed on eleven patients undergoing thyroidectomy surgery to on-line monitor the exhaled propofol. The correlation coefficients (R2) between TRMI-IMS signal intensities and calculated propofol plasma concentrations set in the TCI system were estimated to be in a range of 0.69 to 0.93, demonstrating the potential of TRMI-IMS for on-line predicting the propofol concentration in plasma by exhaled air analysis.

The plasma propofol concentration is important information for anaesthetists to monitor and adjust the anaesthesia depth for patients during a surgery operation. In this paper, a stand-alone ion mobility spectrometer (IMS) was constructed for the rapid measurement of the plasma propofol concentrations. Without any sample pre-treatment, the plasma samples were dropped on a piece of glass microfiber paper and then introduced into the IMS cell by the thermal desorption directly. Each individual measurement could be accomplished within 1 min. For the plasma propofol concentrations from 1 to 12 μg mL−1, the IMS response was linear with a correlation coefficient R2 of 0.998, while the limit of detection was evaluated to be 0.1 μg mL−1. These measurement results did meet the clinical application requirements. Furthermore, other clinically-often-used drugs, including remifentanil, flurbiprofen and atracurium, were found no significant interference with the qualitative and quantitative analysis of the plasma propofol. The plasma propofol concentrations measured by IMS were correlated well with those measured by the high performance liquid chromatography (HPLC). The results confirmed an excellent agreement between these two methods. Finally, this method was applied to monitor the plasma propofol concentrations for a patient undergoing surgery, demonstrating its capability of anaesthesia monitoring in real clinical environments.

Amyotrophic lateral sclerosis (ALS) is an incurable neurological degenerative disease. It can cause irreversible neurological damage to motor neurons; typical symptoms include muscle weakness and atrophy, bulbar paralysis and pyramidal tract signs. The ALS-mimicking disease cervical spondylotic myelopathy (CSM) presents similar symptoms, but analysis of breath volatile organic compounds (VOCs) can potentially be used to distinguish ALS from CSM. In this study, breath samples were collected from 28 ALS and 13 CSM patients. Subsequently, gas chromatography/mass spectrometry (GCMS) was used to analyze breath VOCs. Principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLSDA) were the statistical methods used to process the final data. We identified 4 compounds with significantly decreased levels in ALS patients compared with CSM controls: (1) carbamic acid, monoammonium salt; (2) 1-alanine ethylamide, (S)-; (3) guanidine, N,N-dimethyl-; and (4) phosphonic acid, (p-hydroxyphenyl)-. Currently, the metabolic origin of the VOCs remains unclear; however, several pathways might explain the decreasing trends observed. The results of this study demonstrate that there are specific VOC profiles associated with ALS and CSM patients that can be used to differentiate between the two. In addition, these metabolites could contribute to a better understanding of the underlying pathophysiological mechanisms of ALS.

Currently, there is no adequate, sensitive, reproducible, specific and noninvasive biomarker that can reliably be used to detect renal cell carcinoma (RCC). Previous studies have elucidated the urinary non-volatile metabolic profile of RCC. However, whether urinary volatile organic compound (VOC) profiles are able to identify RCC remains to be elucidated. In the present study, urine was collected from 22 patients with RCC and 25 healthy subjects. Principal component analysis and orthogonal partial least square discriminant analysis were used to compare the data of patients and healthy subjects, and preoperative and postoperative patients undergoing radical nephrectomy. In total, 11 VOC biomarkers were elevated in the RCC patients compared to the healthy subjects, which were phenol; decanal; 1,6-dioxacyclododecane-7,12-dione; 1-bromo-1-(3-methyl-1-pentenylidene)-2,2,3,3-tetramethyl-cyclopropane; nonanal; 3-ethyl-3-methylheptane; isolongifolene-5-ol; 2,5-cyclohexadiene-1,4-dione, 2,6-bis(1,1-dimethylethyl); tetradecane; aniline; and 2,6,10,14-tetramethyl-pentadecane. Three biomarkers were decreased in RCC patients: styrene, 4-heptanone and dimethylsilanediol. In preoperative patients, 2-ethyl-1-hexanol and cyclohexanone were elevated, while 6-t-butyl-2,2,9,9-tetramethyl-3,5-decadien-7-yne were decreased when compared to postoperative patients. Compared with the healthy subjects, RCC has a unique VOC profile, suggesting that VOC profiles may be a useful diagnostic assay for RCC.

Background It has been shown that the application of a lung-protective mechanical ventilation strategy can improve the prognosis of patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). However, the optimal mechanical ventilation strategy for intensive care unit (ICU) patients without ALI or ARDS is uncertain. Therefore, we performed a network meta-analysis to identify the optimal mechanical ventilation strategy for these patients. Methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, EMBASE, MEDLINE, CINAHL, and Web of Science for studies published up to July 2015 in which pulmonary compliance or the partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FIO2) ratio was assessed in ICU patients without ALI or ARDS, who received mechanical ventilation via different strategies. The data for study characteristics, methods, and outcomes were extracted. We assessed the studies for eligibility, extracted the data, pooled the data, and used a Bayesian fixed-effects model to combine direct comparisons with indirect evidence. Results Seventeen randomized controlled trials including a total of 575 patients who received one of six ventilation strategies were included for network meta-analysis. Among ICU patients without ALI or ARDS, strategy C (lower tidal volume (VT) + higher positive end-expiratory pressure (PEEP)) resulted in the highest PaO2/FIO2 ratio; strategy B (higher VT + lower PEEP) was associated with the highest pulmonary compliance; strategy A (lower VT + lower PEEP) was associated with a shorter length of ICU stay; and strategy D (lower VT + zero end-expiratory pressure (ZEEP)) was associated with the lowest PaO2/FiO2 ratio and pulmonary compliance. Conclusions For ICU patients without ALI or ARDS, strategy C (lower VT + higher PEEP) was associated with the highest PaO2/FiO2 ratio. Strategy B (higher VT + lower PEEP) was superior to the other strategies in improving pulmonary compliance. Strategy A (lower VT + lower PEEP) was associated with a shorter length of ICU stay, whereas strategy D (lower VT + ZEEP) was associated with the lowest PaO2/FiO2 ratio and pulmonary compliance. Electronic supplementary material The online version of this article (doi:10.1186/s13054-016-1396-0) contains supplementary material, which is available to authorized users.

Pooled odds ratios for PaO2/FIO2 ratio. Appendix 4B. Pooled odds ratios for ICU length of hospital stay and pooled mean difference for pulmonary compliance. (DOC 32 kb)

Model fit for PaO2/FIO2 ratio results. Appendix 3B. Model fit for compliance results. Appendix 3C. Model fit for ICU length of hospital stay results. (DOC 27 kb)

Summary of excluded articles. (DOC 19 kb)

Rankings based on simulations in terms of PaO2/FIO2 ratio. Appendix 5B. Rankings based on simulations in terms of compliance. Appendix 5C. Rankings based on simulations in terms of ICU length of hospital stay. (DOC 28 kb)

The PaO2/FIO2 ratio effect estimates from multiple treatment meta-analysis compared with direct and indirect estimates, based on back-calculated, and pairwise meta-analyses. Direct and indirect estimates of effect and the corresponding Bayesian I 2 values for inconsistency were calculated. The I 2 values from pooled pairwise meta-analysis for heterogeneity were also calculated. Appendix 2B. The ICU length of hospital effect estimates from multiple treatment meta-analysis compared with direct and indirect estimates, based on back-calculated, and pairwise meta-analyses. Direct and indirect estimates of effect and the corresponding Bayesian I 2 values for inconsistency were calculated. The I 2 values from pooled pairwise meta-analysis for heterogeneity were also calculated. (DOC 80 kb)