[Compound-specific carbon and nitrogen isotope analysis of amino sugars and their applications]. / æ°¨åŸºç³–å•ä½“ç¢³æ°®åŒä½ç´ çš„åˆ†æžåŠå ¶åº”ç”¨.

Amino sugars (AS) are one of the important biochemical components in the natural organic matter pool. Clarifying the sources and transformations of AS would facilitate our understan-ding of the microbial regulation of organic matter. As an emerging technology, compound-specific isotope analysis of amino sugars (CSIA-AS) provides more detailed dynamic information of indivi-dual AS in natural environment. Here, we systematically summarized the determination methods of CSIA-AS and gave an overview on innovative applications in the cycling of AS. CSIA-AS can be performed by gas chromatography-isotope ratio mass spectrometry (GC-IRMS) and ion chromatography-isotope ratio mass spectrometry (IC-IRMS). Each method has its own advantages and disadvantages, but reliable results can be achieved after calibration. The mean residence time of AS is relatively low in soil organic matter, and the bacterial-derived muramic acid possesses a higher minera-lization rate than glucosamine, galactosamine, and mannosamine. The source and metabolic transformation of AS are affected by the substrate, which is related to the specific response of microbial community to different carbon and nitrogen sources. The promotion of CSIA-AS technology requires further optimization of method and integration with other approaches such as microbial screening to decipher the source, transformation, fate and regulatory mechanisms of organic matter.

Infection by the nematode Angiostrongylus cantonensis induces differential expression of miRNAs in mouse brain.

BACKGROUND: The parasitic nematode Angiostrongylus cantonensis is the primary pathogen causing eosinophilic meningitis and meningoencephalitis in nonpermissive hosts. The larval parasites are eliminated by the host's immune responses in the central nervous system (CNS) through infiltration of eosinophils and lymphocytes. This study aimed to determine primary alterations of microRNA (miRNA) during A. cantonensis infection in mice. METHODS: miRNA array was used to analyze the expression of miRNA in uninfected and A. cantonensis-infected mouse brains at 21 days postinfection (dpi). Target genes were predicted by miRDB software, and protein-protein interaction network was analyzed using STRING v9.1. Expression levels of selected miRNAs and cytokine production were verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: Twenty-five mature miRNAs showed differential expression in infected mouse brains, of which 24 were upregulated and one was downregulated compared to the uninfected control. These 25 miRNAs were divided into five clusters, and the first upregulated cluster was selected for further bioinformatics analysis. Target gene prediction and gene ontology (GO) enrichment analysis revealed that the miRNAs were mainly related to the immune response. Furthermore, six target genes of mmu-miR-146a-5p were predicted to interact with tumor necrosis factor alpha (TNF-α). The in vitro study suggested that transfected mmu-miR-146a-5p inhibitor upregulated TNF-α and its target gene Traf6 in microglia following stimulation with A. cantonensis larval antigen. CONCLUSION: This study suggested a critical role of miRNAs in the host defense during A. cantonensis infection, providing new insights into the molecular mechanisms underlying the interaction between mmu-miR-146a-5p and TNF-α in angiostrongyliasis in nonpermissive hosts.

Green tea polyphenol epigallocatechin-3-gallate ameliorates insulin resistance in non-alcoholic fatty liver disease mice.

AIM: Epigallocatechin-3-gallate (EGCG) is a major polyphenol in green tea. In this study, we investigated the effects of EGCG on insulin resistance and insulin clearance in non-alcoholic fatty liver disease (NAFLD) mice. METHODS: Mice were fed on a high-fat diet for 24 weeks. During the last 4 weeks, the mice were injected with EGCG (10, 20 and 40 mg·kg(-1)·d(-1), ip). Glucose tolerance, insulin tolerance and insulin clearance were assessed. After the mice were euthanized, blood samples and tissue specimens were collected. Glucose-stimulated insulin secretion was examined in isolated pancreatic islets. The progression of NAFLD was evaluated histologically and by measuring lipid contents. Insulin-degrading enzyme (IDE) protein expression and enzyme activity were detected using Western blot and immunocapture activity assays, respectively. RESULTS: The high-fat diet significantly increased the body weight and induced grade 2 or 3 liver fatty degeneration (steatosis, lobular inflammation and ballooning) accompanied by severe hyperlipidemia, hyperglycemia, hyperinsulinemia and insulin resistance in the model mice. Administration of EGCG dose-dependently ameliorated the hepatic morphology and function, reduced the body weight, and alleviated hyperlipidemia, hyperglycemia, hyperinsulinemia and insulin resistance in NAFLD mice. Furthermore, EGCG dose-dependently enhanced insulin clearance and upregulated IDE protein expression and enzyme activity in the liver of NAFLD mice. CONCLUSION: EGCG dose-dependently improves insulin resistance in NAFLD mice not only by reducing body weight but also through enhancing the insulin clearance by hepatic IDE. The results suggest that IDE be a potential drug target for the treatment of NAFLD.

Effects and mechanisms of vitamin A and vitamin E on the levels of serum leptin and other related cytokines in rats with rheumatoid arthritis.

Leptin has been identified as an important cytokine in the inflammatory networks of rheumatoid arthritis (RA). Higher serum leptin levels may accelerate the development of RA. This study aimed to examine the effects of vitamin A (VitA) and vitamin E (VitE) on the levels of leptin and other related experimental and clinical indices, and to explore the mechanisms of these effects through the Janus kinase/signal transducer and activator of transcription (STAT) signal transduction pathway in rats with collagen-induced arthritis (CIA). CIA model rats were established by the intradermal injection of bovine type II collagen emulsified in incomplete Freund's adjuvant, followed by a booster intradermal injection. Four weeks later, the CIA model rats were treated with 42.86 µg retinol equivalents/kg body weight (b.w.) VitA or 200 mg/kg b.w. VitE for four weeks. The levels of leptin, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-10, IL-4, C-reactive protein (CRP) and rheumatic factor were measured by ELISA using commercial kits, and the erythrocyte sedimentation rate (ESR) was determined. In addition, the expression levels of phosphorylated (p)-STAT1, p-STAT3 and leptin in the synovium were evaluated by western blot analysis. The results indicated that VitA and VitE significantly reduced the levels of leptin, TNF-α, IL-6 and CRP and the ESR and significantly increased the levels of IL-10 compared with those of the model group. Furthermore, significantly reduced p-STAT3 protein expression levels were observed in the VitA and VitE groups. In conclusion, VitA and VitE reduced the levels of serum leptin protein and other cytokines. Furthermore, VitA and VitE also reduced the p-STAT3 protein levels. The present study may provide a novel approach for the treatment of RA.

Test performance of sputum microRNAs for lung cancer: a meta-analysis.

BACKGROUND: Lung cancer is the leading cause of cancer-related deaths worldwide. Early detection and precise diagnosis are critical for the patients with lung cancer. Increasing evidence has suggested that microRNAs (miRNAs) play important roles in the diagnosis of lung cancer. To evaluate the overall diagnostic performance of sputum miRNAs for the detection of lung cancer, a meta-analysis was performed. METHODS: A systematic search for published literature evaluating the diagnostic accuracy of sputum miRNAs in lung cancer was performed to determine pooled sensitivity and specificity. A summary receiver operating characteristic curve was constructed to assess the overall test performance. Subgroup analysis was utilized to explore potential sources of heterogeneity in the included studies. RESULTS: Eight studies with a total of 514 patients and 491 controls were included in this meta-analysis. Sputum miRNAs had a pooled sensitivity of 0.70 (95% confidence interval [95% CI]: 0.66-0.70) and a pooled specificity of 0.89 (95% CI: 0.86-0.91) for the detection of lung cancer, with an area under the summary receiver operating characteristics curve of 0.83. Significant interstudy heterogeneity for specificity was observed, with miRNA profiles being a possible source. CONCLUSION: Sputum miRNAs are potentially useful noninvasive markers for diagnosis of lung cancer. The diagnostic specificity of sputum miRNAs may be influenced by the miRNA profiles. It would be important for further work to evaluate the generalizability of our results by methodologically rigorous studies on a well-defined patient population.

Pathological changes in the lung and brain of mice during heat stress and cooling treatment.

BACKGROUND: Heatstroke often leads to multiple organ dysfunction syndrome (MODS) with a death rate of 40% or a neurological morbidity of 30%. These high rates in patients with heatstroke are largely due to the progression of heat stress to MODS, resulting in no specific treatment available. This study aimed to develop a mouse model of heat stress and determine the pathological changes in the lung and brain during heat stress and cooling treatment. METHODS: A mouse model of heat stress was established in a pre-warmed incubator set at 35.5 ± 0.5°C and with a relative humidity of 60% ± 5%. Rectal temperature was monitored, and at a temperature of 39 °C, 40 °C, 41 °C, or 42 °C, the mice were sacrificed. The remaining animals were removed from the incubator and cooled at an ambient temperature of 25 ± 0.5 °C and a humidity of 35% ± 5% for 12 or 24 hours at a temperature of 41 °C or for 6 hours at a temperature of 42 °C. The control mice were sham-heated at a temperature of 25 ± 0.5 °C and a humidity of 35% ± 5%. The lungs and brains of all animals were isolated. Hematoxylin and eosin staining and light microscopy were performed to detect pathological changes. RESULTS: All mice demonstrated a uniform response to heat stress. A low degree of heat stress induced marked pathological changes of the lungs. With the rise of the temperature to 42°C, progressively greater damage to the lungs with further congestion of the lung matrix, asystematic hemorrhage of alveolar space, abscission of alveolar epithelial cells, and disappearance of pulmonary alveolus tissue structure were detected. However, absorption of congestion and hemorrhage as well as recovery of pulmonary alveolus tissue structure was observed following cooling treatment at an ambient temperature. With a low degree of heat stress, the brain only showed moderate edema. Neuronal denaturation and necrosis were detected at a temperature of 42°C. Interestingly, the lesions in the brain were further aggravated at 42 °C regardless of cooling treatment, but recovery was observed after cooling treatment at 41 °C. CONCLUSIONS: The pathological changes of the lungs and brain of mice showed distinctive lesions following heat stress and cooling treatment, and they were correlated with the time and duration of cooling treatment. The results of this study are helpful for further study of the mechanisms linking heatstroke.

[Construction of MHV-A59 damp-heat mouse model and analysis of the relevant indices].

OBJECTIVE: To explore the impact of inflammation, water metabolism and immune function on the establishment of a mouse model of damp-heat syndrome with MHV-A59 infection. METHODS: Twenty-four mice were randomly divided into control group, virus group, damp-heat group and model group. The peripheral blood CD4(+) and CD8(+) lymphocytes were detected by flow cytometry, and the serum levels of IFN-γ and IL-4 were assayed by ELISA. The expressions of NF-κB and AQP4 in the liver and stomach were determined using immunohistochemistry. RESULTS: The expression of NF-κB and CD4(+)/CD8(+) ratio in the virus and model groups were significantly higher than those in the damp-heat and control groups, while the expression of AQP4 was significantly higher in the model and damp-heat groups than in the other groups. Compared with the control group, the model group showed a significantly higher ratio of IFN-γ/IL-4. CONCLUSIONS: MHV-A59 virus is the main cause of elevated NF-κB expression and CD4(+)/CD8(+)/ ratio, while damp-heat syndrome is responsible for increased AQP4 expression, and their synergistic effect results in increased IFN-γ/IL-4 ratio. The mouse model established using MHV-A59 virus and the damp-heat factors can mimic damp-heat syndrome described in traditional Chinese medicine theory.

[The mechanism of signal extension in Haoqin Qingdan decoction immunity activity in Damp-heat syndrome of pneumonia disease infected by influenza virus].

OBJECTIVE: To explore the immunoregulation existing signal transduction mechanism, to evaluate the role of lay its experimental basis By using Haoqin Qingdan decoction for treatments on the mouse models. METHODS: A total of 40 NIH Mice were randomly divided into five groups: control group, virus group (infecting by influenza virus), complex model group (richly fatty and sweet diet + Humid heat environment + infecting by influenza virus), virazole group (mouse of model group was treated by virazole), and Haoqin Qingdan decoction group (mouse of complex model group was treated by decoction of Haoqin Qingdan). When the complex model was established, determination of the mice lung indexes in each group and calculate the inhibition of lung indexes. The level of TLR2 mRNA and NF-κB mRNA expressions of peritoneal macrophages in each group of mice were quantitated by reverse transcription-polymerase chain reaction (RT-PCR). The level of IL-4 and IFN-γ in mouse serum was detected by ELISA to calculate the Th1/Th2 (IFN-γ/IL-4). RESULTS: The lung index of control group, virus group, complex model group, virazole group and Haoqin Qingdan decoction group were separately: (0.79 ± 0.11)%, (1.93 ± 0.38)%, (1.41 ± 0.26)%, (1.10 ± 0.26)% and (1.02 ± 0.16)%; The mice of virazole group and Haoqin Qingdan decoction group lung index were decreased (t = 0.322, P < 0.05). TLR2 mRNA expression The results showed that the control group, virus group, complex model group, virazole group and Haoqin Qingdan decoction group were: 0.145 ± 0.017, 0.991 ± 0.149, 0.903 ± 0.124, 0.257 ± 0.03 and 0.413 ± 0.031; Compared to the complex model group, Haoqin Qingdan decoction group and virazole group were decreased (t = 0.422, F = 112.834, P < 0.05). Control group, virus group, complex model group, virazole group and Haoqin Qingdan decoction group NF-κB mRNA expression were separately: 0.075 ± 0.148, 0.379 ± 0.019, 0.291 ± 0.012, 0.169 ± 0.026 and 0.175 ± 0.033; the expression in virazole group and Haoqin Qingdan decoction group were decreased (t = 0.422, F = 112.834, P < 0.05). The level of IFN-γ in mice serum of control group, virus group, complex model group, virazole group and Haoqin Qingdan decoction group were: (7434.06 ± 323.27) pg/ml, (8679.77 ± 198.70) pg/ml, (8068.78 ± 113.8) pg/ml, (7454.66 ± 301.30) pg/ml and (7484.56 ± 229.85) pg/ml respectively; the IFN-γ level in serum of Haoqin Qingdan decoction group and virazole group were decreased (t = 0.201, F = 5.390, P < 0.05). Each group of mice IL-4 contents were (3701.74 ± 256.00) pg/ml, (3569.64 ± 161.35) pg/ml, (3530.88 ± 334.63) pg/ml, (3481.84 ± 282.25) pg/ml and (3618.00 ± 262.16) pg/ml; there were no significant difference between each group (t = 0.414, F = 0.505, P > 0.05). Th1/Th2 type cells in state of equilibrium (means IFN-γ/IL-4) were: 2.02 ± 0.19, 2.38 ± 0.10, 2.36 ± 0.14, 2.22 ± 0.17 and 2.07 ± 0.15; and complex model group Haoqin Qingdan decoction group and virazole group were decreased, and there was no significant difference observed (t = 0.587, F = 3.684, P > 0.05). CONCLUSION: The effect of Haoqin Qingdan decoction on treatment of damp-heat syndrome of pneumonia infected by influenza virus was observed. Through reducing the expressions of TLR2, it decreases the levels of NF-κB mRNA and the proportionality of Th1/Th2 are obviously descend (P < 0.05). Haoqin Qingdan decoction can reduce the lung index and relieve the pathogenic changes.

[Reproduction of a murine model of hyperthermic treatment].

OBJECTIVE: To find out the most suitable conditions for a whole body hyperthermia (WBH) model and the influence of these conditions on the blood brain barrier (BBB) disruption and brain edema in rats. METHODS: Forty male Sprague-Dawley (SD) rats were randomly assigned to four groups (n=10 in each group): control group, group A, group B and group C. After anesthesia with pentobarbital, rats were subjected to femoral artery and vein cannulation. Rats of control group were housed at a controlled room temperature (25-26 degrees C) for 4 hours. Rats of group A, group B and group C were exposed to WBH in a biological oxygen supply heated container (relative humidity 65%, wind velocity 25 cm/s) maintained at 34, 36 and 38 degrees C for 3 hours, respectively. Then the rats were removed from the heated container and their body temperature was cooled down for 1 hour. During heating, rectal temperature, heart rate (HR), mean arterial pressure (MAP), pH, partial pressure of oxygen in artery (PaO(2)), partial pressure of carbon dioxide in artery (PaCO(2)), the dosage of anesthetic, and the mortality rate in each group were recorded. Evans blue (EB) was administered into the femoral vein and allowed to circulate for 5 minutes. At the end of the experiment, the animals were perfused with 0.9% saline and heparin through the heart, and the brain was harvested for the examination of BBB permeability, water content and morphological alterations in brain tissues and neurons. RESULTS: The total dosage of pentobarbital was not significantly different among all groups. After WBH for 3 hours, the average rectal temperature was higher than rats without WBH, and the mortality rate was 0, 10%, 10% and 40% in groups control, A, B, C, respectively. HR of groups A, B and C were significantly higher than those of control group; MAP, pH of group A, B and C were significantly lower than those of control group (all P<0.05). Compared to that of control group, water content of the brain and permeability of EB in groups A, B and C were significantly increased (P<0.05 or P<0.01), but there was no marked difference on PaO(2), PaCO(2) and haematocrit (HCT) among groups A, B and C. Morphological investigation showed that there were different degrees of structural changes in brain tissue in groups A, B and C under light microscopy. Under transmission election microscopy, the structure of nerve cells and BBB in group B and group C showed moderate to profound alterations, but there were no changes in group A. CONCLUSION: Rats housed in a biological oxygen supply heat container with the temperature maintained at 36 degrees C for 3 hours could establish an ideal WBH model with notable BBB breakdown, moderate brain edema, and histological changes in brain.

[Effect of heat stress and preconditioning on proteomics of NIH-3T3 cells].

OBJECTIVE: To establish a heat stress adaptation model in mouse fibroblast cell line NIH-3T3, and analyze the effect of stress and adaptation on protein synthesis. METHODS: A heat stress adaptation cell model was established by heat preconditioning at 42 degrees C for 20 min. The total proteins were separated from the cell lysate by two-dimensional electrophoresis (2-DE), and analyzed using PDQUEST software. The effect of heat stress and preconditioning on protein synthesis was studied, and the protein spots related to stress adaptation were identified by peptide mass fingerprinting (PMF). RESULTS: The proteins with increased expressions in cells with heat stress but not prior preconditioning represented mostly proteins with low molecular mass, whereas in cells exposed to heat stress following heat preconditioning, the upregulated proteins showed a wide spectrum of relative molecular mass. CONCLUSIONS: In stress condition, the cells tend to give priority to synthesis of proteins with small molecular mass. Preconditioning of the cells may increase the intracellular reserve of the protective proteins for protection against challenge with potential stress condition.

[Effects of artesunate on CD14 and toll-like receptor 4 in peritoneal macrophages of mice with heat stroke endotoxemia].

OBJECTIVE: To study the effects of artesunate on CD14 and toll-like receptor 4 (TLR 4) expressions in peritoneal macrophages of mice with heat stroke endotoxemia. METHODS: Kunming mice were randomly divided into the normal temperature group, the hyperthermia group, the normal saline (NS) group and the artesunate group (both i.p.60 mg/kg daily for consecutive five days). The normal temperature group was exposed to the condition of dry bulb temperature (Tdb) 25 degrees C +/- 0.5 degrees C and relative humidity (RH) 43% +/- 5% for 2 hours, while other groups were exposed to the condition of Tdb 35 degrees C +/- 0.5 degrees C and RH 65% +/- 5%. The mRNA expressions of CD14 and TLR 4 in peritoneal macrophages and concentrations of tumor necrosis factor alpha (TNF alpha) in plasma were observed in different time points (1 hour and 2 hour). RESULTS: The mRNA expressions of CD14 and TLR 4 in the normal temperature group were 0.34% +/- 0.047% and 0.31% +/- 0.062% respectively. The expressions of two receptors at 1 hour in the hyperthermia group were significantly increased to 0.53% +/- 0.085% and 0.45% +/- 0.049% compared with the normal group and kept increased at 2 hour (P < 0.01). The mRNA expressions at 1 hour in the NS group were significantly increased but a little bit decreased at 2 hour. The mRNA expressions of CD14 and TLR 4 at 1 hour in the artesunate group were 0.26% +/- 0.051% and 0.25% +/- 0.084% respectively and a little bit decreased at 2 hour. The change of TNF-alpha in each group was almost consistent with the changes of CD14 and TLR 4. CONCLUSION: Artesunate can reduce significantly the expressions of CD14 and TLR 4 in LPS signal transduction pathway and the concentration of TNF-alpha, which perhaps is one of the most important mechanisms that artesunate fights against endotoxemia.

[Protective effects of heat shock response on circulatory collapse induced by hyperthermia].

OBJECTIVE: To investigate the protective effects and mechanism of heat shock response (HSR) on circulatory collapse induced by hyperthermia. METHODS: Two experiments were carried out: (1) Protective effects of HSR. Rats were divided into 2 groups: heat shock (HS) group, sham control (SC) group. After HS group was pretreated with heat shock and recovered for 20 h at room temperature, both groups were exposed to heat till death, and blood pressure, electrocardiogram were measured continuously during exposure. Mean arterial pressure (MAP), survival time etc were acquired through Chart software. (2) Mechanism of effects. Rats were divided into 3 groups: HS group, SC group and normal control (NC) group. The treatment in HS and SC groups was identical with that in the first experiment, but it would be terminated at 73 min after heat exposure. Systolic pressure (Ps), diastolic pressure (Pd) etc were recorded and content of NO and HSP70 in myocardium were measured. RESULTS: (1) The survival time in HS group [(102.3 +/- 11.4) min] was longer than that in SC group [(87.9 +/- 7.7) min] and shock revealed later (P < 0.01); (2) During early heat exposure MAP in HS group was not different from that in SC group, but after 60 min MAP in HS group were higher than that in SC group; (3) MAP, Ps, Pd, HR and HSP70 in HS group were significantly higher but content of NO was lower than those in SC group (P < 0.01, P < 0.05). CONCLUSION: HSR may induce upregulation of HSP70 and inhibit excessive production of NO in myocardium, thus result in relief of circulatory collapse induced by hyperthermia.

[Preventive effects of heat-shock response against circulatory collapse induced by hyperthermia].

OBJECTIVE: To investigate the preventive effects of heat-shock response (HSR) against circulatory collapse induced by hyperthermia and understand its mechanism. METHODS: Twenty-four SD rats were randomized equally into heat-shock group (HS group), high temperature control group (HC group) and normal temperature control group (NC group). The rats in HS group, but not HC group, were subjected to heat shock pretreatment. After a recovery period for 20 h at room temperature, the rats in HS and HC groups were exposed to high temperature environment, and their blood pressures and electrocardiograms were measured continuously. Heat exposure was terminated at 73 min and the contents of myocardial malondialdehyde (MDA) and NO were measured. Using Chart software, the data of the mean arterial pressure (MAP), systolic pressure (SP), diastolic pressure (DP), heart rate (HR) were acquired. The rats in NC group did not receive any treatment to obtain the measurements in normal condition. RESULTS: Compared with NC group, the MAP, SP and DP were significantly lowered (P P<0.01) in HS and HC group and HR accelerated (P P<0.01) after a 73-min heat exposure, and HS group had significantly higher measurements of the above indices than HC group did. In comparison with NC group, the contents of MDA and NO in the myocardium in HC group were significantly elevated after the exposure (P P<0.01). The MDA content in HS group, which was comparable with that of NC group, was significantly lower than that of HC group (P P<0.05), and compared with HC group, HS also had lower NO content (P<0.01). CONCLUSION: HSR may relieve circulatory collapse induced by hyperthermia, which involves the inhibitory effect of HSR on the production of MDA and NO in the myocardium.

Establishment of computer-aided acquisition system of complete blood pressure wave parameters in rats.

OBJECTIVE: To establish an accurate and efficient system for acquiring the complete blood pressure wave parameters in rats. METHODS: With the help of Powlab, the equipment for physiological data recording, and Chart (soft ware), the basal parameters of the the blood pressure waves were acquired in rats, including the parameters of a single wave and the average parameters recorded in 1 min, which were then processed according to mathematical formulas or calculated approximately to acquire other parameters. RESULTS: Through the system the complete parameters of the blood pressure waves were acquired accurately in rats. Compared with the actual values, the results from some approximate calculation showed little difference. CONCLUSION: A precise and automated system for acquiring complete parameters of the blood pressure waves is successfully established in rats, which makes possible more comprehensive and convincing analysis of the blood pressure waves in rats.