[Protective effect of Lindera aggregata on lipopolysaccharide-induced mice acute respiratory distress syndrome by regulating p38MAPK/ERK pathway].

OBJECTIVE: To explore the protective effect of Lindera aggregata on acute respiratory distress syndrome (ARDS) induced by lipopolysaccharide (LPS) in mice and its possible mechanism. METHODS: Forty C57BL/6 mice were randomly divided into sham operation group, ARDS model group, low-dose Lindera aggregata (L-LA) group and high-dose Lindera aggregata (H-LA) group, with 10 mice in each group. ARDS model was established by injecting 5 mg/kg LPS through the trachea. The L-LA group and H-LA group were orally administrated 1 g/kg and 5 g/kg of the Lindera aggregate extract once a day, respectively, while the ARDS model group was given the same volume of normal saline, the sham group received no treatment. The Lindera aggregata was preadministered for 3 days before modeling, and continued for 2 days after modeling, then the animals were sacrificed, and bronchoalveolar lavage fluid (BALF) and lung tissue were collected. The pathological changes of lung tissue in each group of mice were observed under the microscope and the wet/dry weight ratio (W/D) of the lung were measured. Enzyme linked immunosorbent assay (ELISA) was used to examine the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in mice serum and BALF, and flow cytometry was used to detect the expression rate of CD40 on the surface of BALF macrophages. The phosphorylation levels of p38 and extracellular signal-regulated protein kinase 1/2 (ERK1/2) proteins in lung tissue were measured by Western blotting. RESULTS: Lung histopathology under light microscope showed that the damage of alveolar structure, thickening of alveolar septum and infiltration of inflammatory cells in the H-LA group were less severe than those in the ARDS model group, while the pathological characteristics of ARDS in the L-LA group were not significantly different from those in the ARDS model group. Compared with the sham operation group, the lung W/D ratio, TNF-α and IL-6 protein contents in serum and BALF, BALF macrophage CD40 expression rate and lung tissue p38 and ERK1/2 protein phosphorylation levels were significantly increased in ARDS model group. The W/D ratio, the concentrations of TNF-α and IL-6 in serum and BALF, the expression rate of CD40 in BALF macrophages, and the phosphorylation levels of p38 and ERK1/2 protein in lung tissue in the L-LA group were not significantly different from those in the ARDS model group. The above indexes in the H-LA group were significantly lower than those in the ARDS model group and the L-LA group [W/D ratio: 5.70±0.19 vs. 6.20±0.31, 6.01±0.17; serum TNF-α (ng/L): 83.63±15.04 vs. 111.75±18.45, 108.12±13.98; serum IL-6 (ng/L): 111.38±8.75 vs. 244.13±26.85, 227.50±9.37; BALF TNF-α (ng/L): 36.25±2.82 vs. 51.13±5.44, 47.50±5.78; BALF IL-6 (ng/L): 35.63±2.20 vs. 49.63±4.90, 46.38±3.50; CD40 expression rate (%): 23.28±2.45 vs. 30.32±2.40, 28.17±1.98; p-p38/p38: 0.50±0.04 vs. 0.74±0.07, 0.69±0.04; p-ERK1/2/ERK1/2: 0.47±0.07 vs. 0.72±0.07, 0.68±0.05; all P < 0.01]. CONCLUSIONS: Lindera aggregata can inhibit LPS-induced lung inflammation and alleviate lung injury in ARDS mice. The mechanism may be related to the inhibition of the activation of p38 mitogen activated protein kinase/ERK (p38MAPK/ERK) signaling pathway.

Asthma attacks: Patients who survived paraquat poisoning.

A patient who survived acute paraquat (PQ) poisoning for more than 5 years was followed up in the emergency room. The patient had recurrent coughing and wheezing one month after discharge. Re-examination of chest CT showed increased dual lung texture. Spirometry suggested severe ventilatory dysfunction while bronchial dilation test was positive. The serum IgE level was significantly high. It is considered that patients with acute PQ poisoning may develop asthma in the long term.

Xuebijing Injection Ameliorates H2S-Induced Acute Respiratory Distress Syndrome by Promoting Claudin-5 Expression.

OBJECTIVE: To investigate the protective effects and underlying mechanisms of Xuebijing Injection (XBJ) on the lung endothelial barrier in hydrogen sulfide (H2S)-induced acute respiratory distress syndrome (ARDS). METHODS: Sprague-Dawley rats were exposed to H2S (300 ppm) to establish ARDS model, while human pulmonary microvascular endothelial cells (HPMECs) were incubated with NaHS (a H2S donor, 500 µmol/L) to establish cell model. H2S and XBJ were concurrently administered to the rat and cell models. Lung hematoxylin and eosin staining, immunohistochemistry, transmission electron microscopy and wet/dry ratio measurement were used to confirm ARDS induced by H2S in vivo. The expression levels of claudin-5, phosphorylated protein kinase B (p-AKT)/t-AKT and p-forkhead box transcription factor O1 (FoxO1)/t-FoxO1 in vivo and in vitro were also assessed. Paracellular permeability and transepithelial electrical resistance (TEER) were measured to evaluate endothelial barrier function in the cell model. RESULTS: The morphological investigation showed that XBJ attenuated H2S-induced ARDS in rats. XBJ significantly ameliorated both the reduction in TEER and the increased paracellular permeability observed in NaHS-treated HPMECs (P<0.05). The protective effects of XBJ were blocked by LY294002, a phosphatidylinositol 3-kinase (PI3K)/AKT/FoxO1 pathway antagonist (P<0.05). Furthermore, XBJ promoted the expression of claudin-5 and increased the levels of p-AKT and p-FoxO1 in vivo and in vitro (P<0.05). CONCLUSIONS: XBJ ameliorated H2S-induced ARDS by promoting claudin-5 expression via the PI3K/AKT/FoxO1 signaling pathway.

[Two case reports: chronic obstructive pulmonary disease developed in long term survived patients after acute paraquat poisoning].

Patients with acute paraquat poisoning mostly die of respiratory failure, and the surviving ones may live with pulmonary fibrosis, but the long-term changes in lung function are still un-clear. Two patients with acute paraquat poisoning survived for more than 7 years were followed up in Northern Jiangsu People's Hospital to evaluate the imaging and spirometric changes. Eight years after poisoning, 1 patient's chest computerized tomography (CT) revealed interstitial pneumonia, chronic bronchitis, emphysema, accompanied by bronchiectasis. Spirometric test showed very severe obstructive ventilatory dysfunction [percentage of vital capacity (VC) to predicted values was 63.7%, percentage of forced expiratory volume in one second (FEV1) to predicted values was 33.2%, percentage of forced vital capacity (FVC) to predicted values was 64.7%, forced expiratory volume in one second to forced vital capacity (FEV1/FVC) was 52.5%, percentage of maximal mid-expiratory flow (MMEF) to predicted values was 9.9%, percentage of diffusion capacity for carbon monoxide in single breath (DLCO-SB) to predicted values was 49.3%]. The radiography of the other patient who survived over 7 years after poisoning also discovered chronic bronchitis, emphysema and bullae, along with pleural effusion. Spirometry identified severe mixed ventilatory dysfunction, mainly obstructive ventilatory disorder (percentage of VC to predicted values was 47.8%, percentage of FEV1 to predicted values was 35.6%, percentage of FVC to predicted values was 49.3%, FEV1/FVC was 74.1%, percentage of MMEF to predicted values was 17.1%, percentage of DLCO-SB to predicted values was 21.8%). These 2 cases indicate that acute paraquat poisoning had long-term effects on lung structure and pulmonary function, which may be manifested as chronic obstructive pulmonary disease.

The role and mechanism of the annexin A1 peptide Ac2-26 in rats with cardiopulmonary bypass lung injury.

The main causes of lung injury after cardiopulmonary bypass (CPB) are systemic inflammatory response syndrome (SIRS) and pulmonary ischaemia-reperfusion injury (IR-I). SIRS and IR-I are often initiated by a systemic inflammatory response. The present study investigated whether the annexin A1 (ANX-A1) peptidomimetic Ac2-26 by binding to formyl peptide receptors (FPRs) inhibit inflammatory cytokines and reduce lung injury after CPB. Male rats were randomized to the following five groups (n = 6, each): sham, exposed to pulmonary ischaemic-reperfusion (IR-I), IR-I plus Ac2-26, IR-I plus the FPR antagonist, BoC2 (N-tert-butyloxycarbonyl-Phe-Leu-Phe-Leu-Phe) and IR-I plus Ac2-26 and BoC2. Treatment with Ac2-26 improved the oxygenation index, an effect blocked by BoC2. Histopathological analysis of the lung tissue revealed that the degree of lung injury was significantly less (P < 0.05) in the Ac2-26-treated rats compared to the other experimental groups exposed to IR-I. Ac2-26 treatment reduced the levels of the inflammatory cytokines TNF-α, IL-1ß, ICAM-1 and NF-κB-p65 (P < 0.05) compared to the vehicle-treated group exposed to IR-I. In conclusion, the annexin A1 (ANX-A1) peptidomimetic Ac2-26 by binding to formyl peptide receptors inhibit inflammatory cytokines and reduce ischaemic-reperfusion lung injury after cardiopulmonary bypass.

Melatonin enhances the cadmium tolerance of mushrooms through antioxidant-related metabolites and enzymes.

Many wild mushroom species are known to immune heavy metals. However, the mechanism by which this occurs remains largely unsolved. Melatonin (MT) has been proven to play an important defensive role against various abiotic stresses in plants and animals. This study reports on the presence of MT in edible fungi and its role in the response to cadmium (Cd)-induced stress. We found that melatonin was widely distributed in all experimental species and could also relieve Cd-induced damage in the Volvariella volvacea. Comparative metabolic and proteome analyses reveal that tryptophan/proline/tyrosine metabolism, the citrate cycle, nitrogen and glutathione metabolism, and oxidation-reduction processes were enriched after Cd and/or MT addition, indicating an antioxidant mechanism was aroused. Finally, different MT and cadmium treatments were studied for their effects on the expression and activity of oxidation-related enzymes (superoxide dismutase, catalase, peroxidase, etc), which further verified the ameliorative influence of MT on Cd-induced oxidative stress.

Involvement of claudin-5 in H2S-induced acute lung injury.

Acute exposure to hydrogen sulfide (H2S) can cause fatal acute lung injury (ALI). However, the mechanisms of H2S-induced ALI are still not fully understood. This study aims to investigate the role of the tight junction protein claudin-5 in H2S-induced ALI. In our study, Sprague-Dawley (SD) rats were exposed to H2S to establish the ALI model, and in parallel, human pulmonary microvascular endothelial cells (HPMECs) were incubated with NaHS (a H2S donor) to establish a cell model. Lung immunohistochemistry and electron microscopy assays were used to identify H2S-induced ALI, and the expression of claudin-5, p-AKT/t-AKT and p-FoxO1/t-FoxO1 was detected. Our results show that H2S promoted the formation of ALI by morphological investigation and decreased claudin-5 expression. Dexamethasone (Dex) could partly attenuate NaHS-mediated claudin-5 downregulation, and the protective effects of Dex could be partially blocked by LY294002, a PI3K/AKT/FoxO1 pathway antagonist. Moreover, as a consequence of the altered phosphorylation of AKT and FoxO1, a change in claudin-5 with the same trend was observed. Therefore, the tight junction protein claudin-5 might be considered a therapeutic target for the treatment of ALI induced by H2S and other hazardous gases.

Validation of Reference Genes for Gene Expression Normalization in RAW264.7 Cells under Different Conditions.

RAW264.7 is a macrophage strain derived from mice tumour and shows a significant ability in antigen uptake. Real-time quantitative PCR (RT-qPCR) is one of the most commonly used methods in gene studies and requires suitable reference genes to normalize and quantitate the expression of gene of interest with sensitivity and specificity. However, suitable reference genes in RAW264.7 cells have not yet been identified for accurate gene expression quantification. In the current study, we evaluated expression levels of ten candidate reference genes in RAW264.7 cells under different conditions. RT-qPCR results indicated significant differences in the expression levels among the ten reference genes. Statistical analyses were carried out using geNorm, NormFinder, and BestKeeper software to further investigate the stability of the reference genes. Integrating the results from the three analytical methods, cytochrome c-1 and hydroxymethylbilane synthase were found to be the most stable and therefore more suitable reference genes, while ribosomal protein L4 and cyclophilin A were the least stable. This study emphasises the importance of identifying and selecting the most stable reference genes for normalization and provides a basis for future gene expression studies using RAW264.7 cells.

Selection and validation of appropriate reference genes for real-time quantitative PCR analysis in Momordica charantia.

Real time quantitative reverse transcription PCR (RT-qPCR) has been attracting more attention for its high sensitivity in gene expression analysis. Given the widely use of RT-qPCR in normalization, it is playing a pivotal role for seeking suitable reference genes in different species. In current work, 12 candidate reference genes including Actin 2 (ACT2), Cyclophilin 2 (CYP2), Glyceraldehyde-3-phosphate dehydrogenase C2 (GAPC2), Elongation factor 1-α (EF1-α), Nuclear cap binding protein 20 (NCBP20), Serine/threonine-protein phosphatase PP2A (PP2A), Polypyrimidine tract-binding protein 1 (PTBP1), SAND family protein (SNAD), TIP41-like protein (TIP41), Tubulin beta-6 (TUB6), Ubiquitin-conjugating enzyme 9 (UBC9) and Glyceraldehyde-3-phosphatedehydrogenase (GAPDH) were screened from the transcriptome datasets of M. charantia. Afterwards, GeNorm, NormFinder and BestKeeper algorithms were applied to assess the expression stability of these 12 genes under different abiotic stresses including drought, cold, high-salt, hormone, UV, oxidative and metal stress. The results indicated that 12 selected genes exhibited various stability across the samples under different external stress conditions, but TIP41, PTBP1 and PP2A presented high stability among all the reference genes. To validate the suitability of the identified reference genes, the results of hormone subset were compared with RNA sequencing (RNA-seq) data, and the relative abundance of Ascorbate peroxidase 1（APX1）was used to confirm the reliability of the results. This work assesses the stability of reference genes in M. charantia under different abiotic stress conditions, which will be beneficent for accurate normalization of target genes in M. charantia.

Two PBDEs exposure inducing feeding depression and disorder of digestive and antioxidative system of Daphnia magna.

2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) are two typical polybrominated diphenyl ethers (PBDEs), and studies have proven that these PBDs can disrupt the behaviors and physical function of aquatic organisms. However, little is known about the compositional impacts of BDE-47/BDE-99 compound pollution on the feeding behavior of Daphnia magna. In this study, a response surface methodology (RSM) was introduced into the combined toxicity assessment of BDE-47 and BDE-99 on the feeding depression of D. magna. Low concentrations of BDE-47 (9.2 µg/L) and BDE-99 (5.4 µg/L) had no effect on the feeding behavior of D. magna; nevertheless, the feeding depression was strengthened, and a concentration-dependent effect was observed with increasing concentrations of BDE-47 and BDE-99. The results of RSM indicated that the mixture of BDE-47 and BDE-99 can enhance their toxicity on the feeding behavior of D. magna. Moreover, real-time PCR (qPCR) analysis showed that the down-regulation of α-amylase (AMS) appeared in most of the exposed D. magna. However, there were significant different in the gene expression of trypsin, superoxide dismutase (SOD) and catalase (CAT) between the exposure and control groups. The change in the enzyme activity of AMS, trypsin, SOD and CAT implied that BDE-47 and BDE-99 cause damage to the digestive and antioxidative systems of D. magna. Correlation analysis indicated that a significant positive correlation existed between the gene expression and enzyme activity of SOD and CAT. Our results contribute to the understanding of toxicity caused by BDE-47/BDE-99 compound pollution in D. magna and help to improve traditional toxicity assessment methods for aquatic environments.

A meta-analysis of early oral refeeding and quickly increased diet for patients with mild acute pancreatitis.

BACKGROUND/AIM: The objective of the study is to clarify whether early oral refeeding (EORF) and quickly increasing diet (QID) are of benefit to patients with mild acute pancreatitis compared with a traditional oral refeeding strategy. MATERIALS AND METHODS: Studies were searched in PubMed, Cochrane library, ScienceDirect, SpringerLink, China Biology Medicine disc and Embase. A meta-analysis was then performed, using relapse of abdominal pain, nausea/vomiting, and length of hospital stay (LOHS) as the evaluation indices. RESULTS: Eight trials met the inclusion criteria. For the oral refeeding time group, EORF could significantly decrease the LOHS (mean deviation [MD] -1.97; 95% confidence interval (CI) -3.32 to -0.62;P = 0.004), and there was no significant difference for relapse of abdominal pain (relative risk [RR] 1.17; 95% CI 0.69-2.00;P = 0.56) or nausea/vomiting (RR 1.30; 95% CI 0.19-8.82;P = 0.79) when compared with conventional oral refeeding. For the oral refeeding material group, there was no significant difference for relapse of abdominal pain (RR 0.86; 95% CI 0.53-1.40;P = 0.54), nausea/vomiting (risk difference -0.01; 95% CI -0.19-0.18;P = 0.94), or LOHS (MD -0.88; 95% CI -2.24-0.48;P = 0.20) between the QID and stepwise increasing diet groups. CONCLUSION: Pure EORF or QID caused no damage to patients with mild acute pancreatitis, and EORF could significantly decrease the LOHS.

Chemical nanosensors based on molecularly-imprinted polymers doped with silver nanoparticles for the rapid detection of caffeine in wastewater.

Caffeine is a common pharmaceutical and personal care product pollutant in wastewater. This work offers rapid and single-step detection of caffeine in an aquatic matrix based on high performance surface-enhanced Raman scattering (SERS). Novel chemical SERS nanosensors were developed employing molecularly-imprinted polymer (MIP) particles loaded with Ag nanoparticles (AgNPs) using precipitation polymerization to form AgNPs@MIP nanocomposites. Theophylline was applied as a dummy template molecule in the synthesis process due to its high structural similarity with caffeine and greater availability. The nanocomposite was characterized by Fourier transform infrared spectroscopy(FTIR), X-ray diffraction(XRD), and ultraviolet-visible (UV-vis) spectroscopy. Static and kinetic adsorption testing demonstrated the specific affinity of AgNPs@MIP nanocomposites for caffeine and a rapid adsorption equilibration rate. Moreover, a simple solid phase extraction cartridge comprising AgNPs@MIP nanocomposites as adsorbents (AgNPs@MISPE), a syringe, and a removable microporous membrane were employed to detect the SERS signal of caffeine. The AgNPs@MISPE was used to detect caffeine with excellent uniformity (relative standard deviation, RSD = 4.8%) and good repeatability (RSD = 8.7%). The separation and detection processes were integrated into a single step, and the overall analysis time was 23 min. The detection limit was 100 ng L-1, which is less than the caffeine content reported in many rivers. The experimental results demonstrate that the proposed chemical nanosensors are a low-cost and reliable tool for the rapid screening of caffeine in wastewater or other aquatic matrices.

Selection and Evaluation of Appropriate Reference Genes for RT-qPCR Normalization of Volvariella volvacea Gene Expression under Different Conditions.

Volvariella volvacea (V. volvacea), commonly referred to as Chinese (paddy straw) mushroom, is a basidiomycete with a protein-rich volva and pileus. Selecting appropriate reference genes is a crucial step in the normalization of quantitative real-time PCR data. Therefore, 12 candidate reference genes were selected from the V. volvacea transcriptome based on previous studies and then BestKeeper, geNorm, and NormFinder were used to identify reference genes stably expressed during different developmental stages and conditions. Of the 12 candidate reference genes, SPRY domain protein (SPRYp), alpha-tubulin (TUBα), cyclophilin (CYP), L-asparaginase (L-asp), and MSF1-domain-containing protein (MSF1) were the most stably expressed under different experimental conditions, while 18S ribosomal RNA (18S), 28S ribosomal RNA (28S), and beta-actin (ACTB) were the least stably expressed. This investigation not only revealed potential factors influencing the suitability of reference genes, but also identified optimal reference genes from a pool of candidate genes under a wide range of conditions.

Baicalin attenuates angiotensin II-induced endothelial dysfunction.

Angiotensin II (Ang II) has been shown to activate multiple downstream pathways resulting in endothelial dysfunction and oxidative stress. Baicalin, a natural flavone, exerts anti-oxidant and anti-apoptotic effects in cardiovascular diseases. In the present study, we hypothesized that baicalin has beneficial effects in Ang II-induced endothelial cells injury. Here, we shown that baicalin improved endothelial fuction impaired by Ang II through promoting endothelial-dependent vasodilation and suppressing the apoptosis of HUVECs in which baicalin decreased the expression of bax and cleaved caspase-3, and increased bcl-2 expression. Additionally, baicalin significantly conversed Ang II to angiotensin-1-7 [Ang-(1-7)] by activating angiotensin-converting enzyme 2 (ACE2) and Mas receptor mRNA expression and protein expression. Moreover, treatment with baicalin significantly reduced cell oxidative damage induced by Ang II through MDA/ROS decrease and NO/T-AOC increase. This antioxidant capacity was related to the increases of PI3K, phosphor-AKT (Ser-473) and phosphor-eNOS (Ser-1177). In conclusion, our results implicate that baicalin could protect endothelial cells from Ang II-induced endothelial dysfunction and oxidative stress via modulating the expression of bax, bcl-2 and cleaved caspase-3, activating ACE2/Ang-(1-7)/Mas axis and up-regulating PI3K/AKT/eNOS pathway.

Hydrophobic-hydrophilic monolithic dual-phase layer for two-dimensional thin-layer chromatography coupled with surface-enhanced Raman spectroscopy detection.

Hydrophobic-hydrophilic monolithic dual-phase plates have been prepared by a two-step polymerization method for two-dimensional thin-layer chromatography of low-molecular-weight compounds, namely, several dyes. The thin 200 µm poly(glycidyl methacrylate-co-ethylene dimethacrylate) layers attached to microscope glass plates were prepared using a UV-initiated polymerization method within a simple glass mold. After cutting and cleaning the specific area of the layer, the reassembled mold was filled with a polymerization mixture of butyl methacrylate and ethylene dimethacrylate and subsequently irradiated with UV light. During the second polymerization process, the former layer was protected from the UV light with a UV mask. After extracting the porogens and hydrolyzing the poly(glycidyl methacrylate-co-ethylene dimethacrylate) area, these two-dimensional layers were used to separate a mixture of dyes with great difference in their polarity using reversed-phase chromatography mode within the hydrophobic layer and then hydrophilic interaction chromatography mode along the hydrophilic area. In the latter dimension only the specific spot was developed further. Detection of the separated dyes could be achieved with surface-enhanced Raman spectroscopy.

[Determination of four insecticide residues in honey and royal jelly by gas chromatography-negative chemical ionization mass spectrometry].

A method was developed for the determination of four insecticide residues in honey and royal jelly by gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS). The honey and royal jelly samples were treated with different preparation methods as the result of the different components. The honey sample was extracted with ethyl acetate and cleaned up with primary second amine, and the royal jelly sample was extracted with acetonitrile-water (1:1, v/v), and cleaned up with a C18 solid-phase extraction column. Finally, the extracts of the honey and royal jelly were analyzed by GC-NCI/MS in selected ion monitoring (SIM) mode separately. External standard calibration method was used for quantification. The linearities of calibration curves of the four insecticides were good with the correlation coefficients greater than 0.99 in the range of 50-500 microg/L. The limits of the detection (LODs) of the four insecticides were in the range of 0.12- 5.0 microg/kg, and the limits of the quantification (LOQs) were in the range of 0.40-16.5 microg/kg. The recoveries of the four insecticides spiked in honey and royal jelly at three spiked levels (10, 15 and 20 microg/kg) were in the range of 78.2 -110.0%, and the relative standard deviations (RSDs) were all below 14%. The sensitivity and selectivity of this method were good with no interfering peaks. The proposed method is simple quick and effective to analyze the four insecticide residues in honey and royal jelly.

[Value of arterial lactic acid and buffer excess in predicting the prognosis of patients with paraquat poisoning].

OBJECTIVE: To investigate the early prognostic values of arterial lactate and base excess (BE) in patients with paraquat poisoning. METHODS: Seventy-five patients with paraquat poisoning were divided into sudden death group (n = 10) who died within 24 h after admission, recent death group (n = 31) who died more than 24 h after admission, and survival group (n = 34). Arterial lactate and BE were measured on admission and at 24 h after admission. The prognostic values of arterial lactate and BE were analyzed. RESULTS: The arterial lactate measured on admission was significantly higher in the sudden death group than in the recent death group and survival group (P < 0.01), but there was no significant difference in arterial lactate between the recent death group and survival group (P = 0.309). The BE measured on admission was significantly lower in the sudden death group than in the recent death group and survival group, and it was significantly lower in the recent death group than in the survival group (P < 0.01 or P < 0.05). At 24 h after admission, the recent death group had a significantly higher arterial lactate (P < 0.01) and a significantly lower BE (P < 0.01), as compared with the survival group. The logistic regression analysis showed that the two indices were significantly associated with prognosis (P < 0.01). On admission, the areas under the receiver operating characteristic (ROC) curve (AUCs) of arterial lactate and BE for predicting death were 0.692 and 0.787, respectively, and the cut-off values were 3.25 mmol/L and -1.75 mmol/L, respectively; the AUCs of arterial lactate and BE for predicting sudden death were 0.995 and 1, respectively, and the cut-off values were 7.1 mmol/L and -12.8 mmol/L, respectively. At 24 h after admission, the AUCs of arterial lactate and BE for predicting death were 0.743 and 0.822, respectively, and the cut-off values were 2.15 mmol/L and -5.55 mmol/L, respectively. CONCLUSION: Arterial lactate and BE have certain values in predicting the death, especially the sudden death, in patients with acute paraquat poisoning.

[Effect and mechanism of gastrodin in relaxing isolated thoracic aorta rings in rats].

OBJECTIVE: To investigate the effect of gastrodin in relaxing isolated thoracic aorta rings in rats and discuss its possible mechanism. METHOD: Isotonic tension of isolated thoracic aortic rings in rats with norepineprine (NE) and KCl was recorded to observe the vasodilatory effect of gastrodin and the influence of various drugs on it. RESULT: Gastrodin had the effect in relaxing thoracic aortas with or without endothelium, and there was no significant difference. NG-nitro-L-argininemethylester (L-NAME, 1 x 10(-4) mol x L(-1)), methylene blue (MB, 1 x 10(-5) mol x L(-1)), indomethacin (INDO, 1 x 10(-5) mol x L(-1)) had no effect on the vasodilation action of gastrodin on thoracic aortas precontracted by NE. 4-aminopyrimide (4-AP, 1 x 10(-4) mol x L(-1)), tetrathylamonium (TEA, 1 x 10(-3) mol x L(-1)), BaCl2 (1 x 10(-4) mol x L(-1)) and glibenclamide (Gli, 1 x 10(-5) mol x L(-1)) could inhibit gastrodin's effect in relaxing thoracic aorta rings. In the absence of Ca2+, pre-incubated gastrodin showed a notable inhibitory effect in relaxing NE contraction. CONCLUSION: Gastrodin shows a dose-dependent and endothelium-independent effect in relaxing rat isolated thoracic aorta rings. The mechanism is related to K+ channel, inhibition of release of Ca+ stored in endoplasmic reticulum of vascular smooth muscle cells and inflow of external calcium Ca2+.