Combination therapy of molecular hydrogen and hyperoxia improves survival rate and organ damage in a zymosan-induced generalized inflammation model

Multiple organ dysfunction syndrome (MODS) is a leading cause of mortality in critically ill patients. Hyperoxia treatment may be beneficial to critically ill patients. However, the clinical use of hyperoxia is hindered as it may exacerbate organ injury by increasing reactive oxygen species (ROS). Hydrogen gas (H₂) exerts a therapeutic antioxidative effect by selectively reducing ROS. Combination therapy of H₂ and hyperoxia has previously been shown to significantly improve survival rate and organ damage extent in mice with polymicrobial sepsis. The aim of the present study was to investigate whether combination therapy with H₂ and hyperoxia could improve survival rate and organ damage in a zymosan (ZY)-induced generalized inflammation model. The results showed that the inhalation of H₂ (2%) or hyperoxia (98%) alone improved the 14-day survival rate of ZY-challenged mice from 20 to 70 or 60%, respectively. However, combination therapy with H₂ and hyperoxia could increase the 14-day survival rate of ZY-challenged mice to 100%. Furthermore, ZY-challenged mice showed significant multiple organ damage characterized by increased serum levels of aspartate transaminase, alanine transaminase, blood urea nitrogen and creatinine, as well as lung, liver and kidney histopathological scores at 24 h after ZY injection. These symptoms where attenuated by H₂ or hyperoxia alone; however, combination therapy with H₂ and hyperoxia had a more marked beneficial effect against lung, liver and kidney damage in ZY-challenged mice. In addition, the beneficial effects of this combination therapy on ZY-induced organ damage were associated with decreased serum levels of the oxidative product 8-iso-prostaglandin F2α, increased activity of superoxide dismutase and reduced levels of the proinflammatory cytokines high-mobility group box 1 and tumor necrosis factor-α. In conclusion, combination therapy with H₂ and hyperoxia provides enhanced therapeutic efficacy against multiple organ damage in a ZY-induced generalized inflammation model, suggesting the potential applicability of H₂ and hyperoxia in the therapy of conditions associated with inflammation-related MODS.

Hydrogen-Rich Medium Attenuated Lipopolysaccharide-Induced Monocyte-Endothelial Cell Adhesion and Vascular Endothelial Permeability via Rho-Associated Coiled-Coil Protein Kinase

Sepsis is the leading cause of death in critically ill patients. In recent years, molecular hydrogen, as an effective free radical scavenger, has been shown a selective antioxidant and anti-inflammatory effect, and it is beneficial in the treatment of sepsis. Rho-associated coiled-coil protein kinase (ROCK) participates in junction between normal cells, and regulates vascular endothelial permeability. In this study, we used lipopolysaccharide to stimulate vascular endothelial cells and explored the effects of hydrogen-rich medium on the regulation of adhesion of monocytes to endothelial cells and vascular endothelial permeability. We found that hydrogen-rich medium could inhibit adhesion of monocytes to endothelial cells and decrease levels of adhesion molecules, whereas the levels of transepithelial/endothelial electrical resistance values and the expression of vascular endothelial cadherin were increased after hydrogen-rich medium treatment. Moreover, hydrogen-rich medium could lessen the expression of ROCK, as a similar effect of its inhibitor Y-27632. In addition, hydrogen-rich medium could also inhibit adhesion of polymorphonuclear neutrophils to endothelial cells. In conclusion, hydrogen-rich medium could regulate adhesion of monocytes/polymorphonuclear neutrophils to endothelial cells and vascular endothelial permeability, and this effect might be related to the decreased expression of ROCK protein.

[Effects of hydrogen-rich medium on lipopolysaccharide-induced intestinal epithelial barrier dysfunction of human colon carcinoma cells]

OBJECTIVE

To investigate the effects of hydrogen-rich medium on lipopolysaccharide (LPS)-induced intestinal epithelial barrier dysfunction of human intestinal epithelial (Caco2) cells.

METHODS

Caco2 cells (passages 28-35) were purchased from the Cell Bank of the Shanghai Institute of Cell Biology, Chinese Academy of Sciences in Shanghai, China, and they were cultured in Dulbecco minimum essential medium (DMEM) containing 20% fetal bovine serum. These cells were randomly divided into four groups: control group (group A), hydrogen-rich medium group (group B), LPS group (group C) and LPS + hydrogen-rich medium group (group D). Cells were cultured with normal medium in group A and group C or with hydrogen-rich medium in group B and group D. Meanwhile, 1 g/L LPS was simultaneously added into group C and group D, while an equivalent volume of normal saline was added into group A and group B instead. In vitro intestinal epithelial models were reproduced with monolayer filter-grown Caco2 and intestinal epithelium. The trans-epithelial electrical resistance (TEER) in models of each group was measured at different incubation times (0, 3, 6, 12, 24 and 48 hours). Cell viability and cytotoxicity were assessed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) release assay, respectively, after incubation for 24 hours. The expression levels of claudin-1 and occludin were respectively determined at 6, 12 and 24 hours of incubation by Western Blot assay. The morphological structure of claudin-1 and occludin was respectively observed after incubation for 24 hours with immunofluorescence staining.

RESULTS

There was no statistical significance in variables between group A and group B. Compared with group A, it was shown that TEER was time-dependently decreased in groups C and D after 6 hours. Compared with group C, TEER in group D was increased after 6 hours. Compared with group A, the cell viability was significantly reduced in group C [(67.2±7.9)% vs. (100.0±0.0)%, P < 0.05] and cell injury was obvious [LDH release rate: (38.5±2.1)% vs. (1.2±0.3)%, P < 0.05]; the expression levels of claudin-1 and occludin at 6, 12, 24 hours were significantly down-regulated [claudin-1 (gray value): 0.351±0.079, 0.272±0.075, 0.190±0.049 vs. 0.518±0.030; occludin (gray value): 0.416±0.044, 0.290±0.062, 0.226±0.019 vs. 0.602±0.038, all P < 0.05], and the structure of claudin-1 and occludin were profoundly disrupted. Compared with group C, it was shown that the cell viability was significantly increased in group D [(88.8±7.4)% vs. (67.2±7.9)%, P < 0.05] and cell injury was significantly abated [LDH release rate: (16.4±4.3)% vs. (38.5±2.1)%, P < 0.05]; the expression levels of claudin-1 and occludin were significantly up-regulated at 24 hours [claudin-1 (gray value): 0.428±0.046 vs. 0.190±0.049, occludin (gray value): 0.466±0.071 vs. 0.226±0.019, both P < 0.05]; the disrupted structures of claudin-1 and occludin were partially recovered.

CONCLUSION

Hydrogen-rich medium can effectively attenuate LPS-induced dysfunction of intestinal epithelial barrier in human Caco2 cells by ameliorating cell viability as well as regulating claudin-1 and occludin expression and structure.

HGF/Met and FOXM1 form a positive feedback loop and render pancreatic cancer cells resistance to Met inhibition and aggressive phenotypes

Purpose

Hepatocyte growth factor (HGF)/Met signaling plays critical roles in pancreatic ductal adenocarcinoma (PDA) development and progression and is considered a potential therapeutic target for this disease. However, the mechanism of aberrant activation of HGF/Met signaling and resistance to Met inhibition in PDA remains unclear.

Experimental Design

The mechanistic role of cross-talk between Forkhead box M1 (FOXM1) and HGF/Met signaling in promotion of PDA growth and resistance to Met inhibition was examined using cell culture, molecular biology and mouse models; and the relevance of our experimental and mechanistic findings were validated using human PDA tissues.

Results

Met was markedly overexpressed in both PDA cell lines and pancreatic tumor specimens, and the expression of Met correlated directly with that of FOXM1 in human tumor specimens. Mechanistically, FOXM1 bound to the promoter region of the Met gene and transcriptionally increased the expression of Met. Increased expression of FOXM1 enhanced the activation of HGF/Met signaling and its downstream pathways, including RAS/extracellular signal-regulated kinase 1/2, phosphoinositide 3-kinase/AKT, and signal transducer and activator of transcription 3. Furthermore, activation of HGF/Met signaling increased the expression and transcriptional activity of FOXM1, and the cross-talk between FOXM1 and HGF/Met signaling promoted PDA growth and resistance to Met inhibition.

Conclusions

Collectively, our findings identified a positive feedback loop formed by FOXM1 and HGF/Met and revealed that this loop is a potentially effective therapeutic target for PDA.

The use of reduced copper metal–organic frameworks to facilitate CuAAC click chemistry

A reduced copper metal–organic framework (rCu-MOF) containing Cu^I ions was prepared and employed as a catalyst for ‘Click’ reactions. The rCu-MOF presents higher catalytic activity, good structural stability as well as facile recyclability compared to traditional copper halide catalysts.

A Selective V(1A) Receptor Agonist, Selepressin, Is Superior to Arginine Vasopressin and to Norepinephrine in Ovine Septic Shock

OBJECTIVE

Selective vasopressin V(1A) receptor agonists may have advantages over arginine vasopressin in the treatment of septic shock. We compared the effects of selepressin, a selective V(1A) receptor agonist, arginine vasopressin, and norepinephrine on hemodynamics, organ function, and survival in an ovine septic shock model.

DESIGN

Randomized animal study.

SETTING

University hospital animal research laboratory.

SUBJECTS

Forty-six adult female sheep.

INTERVENTIONS

Fecal peritonitis was induced in the anesthetized, mechanically ventilated, fluid-resuscitated sheep, and they were randomized in two successive phases. Three late-intervention groups (each n = 6) received IV selepressin (1 pmol/kg/min), arginine vasopressin (0.25 pmol [0.1 mU]/kg/min), or norepinephrine (3 nmol [0.5 μg]/kg/min) when mean arterial pressure remained less than 70 mm Hg despite fluid challenge; study drugs were thereafter titrated to keep mean arterial pressure at 70-80 mm Hg. Three early-intervention groups (each n = 7) received selepressin, arginine vasopressin, or norepinephrine at the same initial infusion rates as for the late intervention, but already when mean arterial pressure had decreased by 10% from baseline; doses were then titrated as for the late intervention. A control group (n = 7) received saline. All animals were observed until death or for a maximum of 30 hours.

MEASUREMENTS AND MAIN RESULTS

In addition to hemodynamic and organ function assessment, plasma interleukin-6 and nitrite/nitrate levels were measured. In the late-intervention groups, selepressin delayed the decrease in mean arterial pressure and was associated with lower lung wet/dry weight ratios than in the other two groups. In the early-intervention groups, selepressin maintained mean arterial pressure and cardiac index better than arginine vasopressin or norepinephrine, slowed the increase in blood lactate levels, and was associated with less lung edema, lower cumulative fluid balance, and lower interleukin-6 and nitrite/nitrate levels. Selepressin-treated animals survived longer than the other animals.

CONCLUSIONS

In this clinically relevant model, selepressin, a selective V(1A) receptor agonist, was superior to arginine vasopressin and to norepinephrine in the treatment of septic shock, especially when administered early.

Effect of ORF119 gene deletion on the replication and virulence of orf virus

Orf is a severe infectious disease of sheep and goats caused by orf virus (ORFV). To investigate the role of ORF119 gene of ORFV, we constructed ORFV with deleted ORF119 gene and LacZ as reporter gene (ORFV-Δ119-LacZ) via homologous recombination. The results showed that wild-type ORF-SHZ1 and ORFV-Δ119-LacZ deletion viruses replicated in Vero cells to similar titers. Relative transcriptional levels of virulence genes OVIFNR, GIF, VEGF and VIL-10 of ORFV-Δ119-LacZ deletion virus were slightly but not significantly lower after 24 hr compared with the wtORF-SHZ1 virus. In vivo experiments showed that 2-month-old lambs inoculated with ORFV-Δ119-LacZ deletion virus exhibited a similar total clinical score compared with those inoculated with wtORF-SHZ1 virus. Based on these results, we conclude that deletion of the ORF119 gene has no significant effect on ORFV replication and virulence.

Hydrogen-rich saline attenuates chemotherapy-induced ovarian injury via regulation of oxidative stress

Hydrogen has been reported to exert a therapeutic effect in several diseases due to its antioxidative, anti-inflammatory and anti-apoptotic properties. The aim of the present study was to investigate whether hydrogen-rich saline treatment could attenuate ovarian damage induced by cisplatin. A total of 240 adult, virgin, female Sprague Dawley rats, weighing 180-220 g, were randomly divided into four groups (n=60 per group): Control (Con), control + hydrogen-rich saline (Con + H₂), cisplatin-induced ovarian injury (OI) and cisplatin-induced ovarian injury + hydrogen-rich saline (OI + H₂). Cisplatin was diluted in saline immediately before use. In the OI and OI + H₂ groups, the rats were administered a dose of cisplatin on the 1st and 7th days. The rats in the Con + H₂ and OI + H₂ groups were intraperitoneally injected with hydrogen-rich saline (10ml/kg body weight) once a day over a 2-week period. On the 14th, 28th and 42nd days (T₁, T₂ and T₃) after the cisplatin injection, femoral vein blood was collected. At the end of the experiment, ovarian homogenates were prepared, and the samples were used for estrogen (E₂), follicle-stimulating hormone (FSH), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) examination. In addition, rats (n=10 per group) were sacrificed for bilateral ovary removal; one was fixed in formalin for follicle-counting analysis, while the other was used for nuclear factor erythroid 2-related factor 2 (Nrf2) detection by western blotting. Hydrogen-rich saline attenuated the FSH release, elevated the level of E₂, improved the development of follicles, and reduced the damage to the ovarian cortex at T₁, T₂ and T₃ in the OI + H₂ rats. Cisplatin induced oxidative stress by increasing the levels of oxidation products and attenuating the activity of antioxidant enzyme, which could be reversed by hydrogen-rich saline treatment. Furthermore, hydrogen-rich saline regulated the Nrf2 protein expression in rats with ovarian damage. In conclusion, hydrogen-rich saline exerts a protective effect against cisplatin-induced ovarian injury by reducing MDA and increasing SOD and CAT activity. Ovarian injury induced by chemotherapy involves the activation of Nrf2.

Internalization of GluA2 and the underlying mechanisms of cognitive decline in aged rats following surgery and prolonged exposure to sevoflurane

BACKGROUND

We revealed that a high concentration of sevoflurane exacerbated cognitive impairment in aged rats, and the inhibition of GluA2 subunit internalization facilitated neuroprotection after a cerebral ischemic injury. However, the trafficking of GluA2 in POCD and its underlying mechanism are not clear. We thus detected the effects of sevoflurane for different inhalation durations on postoperative cognitive function and investigated the role of GluA2 subunit trafficking in this process.

METHODS

A rat model of orthopedic surgery was performed with different durations of 1.5 MAC sevoflurane inhalation. Cognitive function was evaluated by manipulating the Y maze and fear conditioning tests for 7 days after experiments. Western blot, ELISA and coimmunoprecipitation were applied to analyze GluA2 internalization, PI3K expression and its activity, as well as alterations to the MEF2-Arc pathway in the hippocampus. Neuron apoptosis and the spine morphology in the hippocampus were also observed.

RESULTS

We found that neuron apoptosis and GluA2 internalization increased following surgery and 1.5 MAC sevoflurane inhalation for 2h, possibly due to the decrease of the PI3K-GluA2 complex and PI3K activity in the hippocampus after prolonged 1.5 MAC sevoflurane inhalation. We also observed that the MEF2-Arc pathway contributed to long-term cognitive function, which also impaired the spinal morphology after 1.5 MAC sevoflurane inhalation for 2h.

CONCLUSION

The above results suggest that 1.5 MAC sevoflurane inhalation for 2h potentiated surgery-impaired cognitive function and that the inhibition of PI3K-AMPAR GluA2 as well as activation of the MEF2-Arc signal pathway contributes to different stages of POCD.

Hydrogen-rich saline reduces cell death through inhibition of DNA oxidative stress and overactivation of poly (ADP-ribose) polymerase-1 in retinal ischemia-reperfusion injury

Overactivation of poly (ADP-ribose) polymerase 1 (PARP-1), as a result of sustained DNA oxidation in ischemia-reperfusion injury, triggers programmed cell necrosis and apoptosis. The present study was conducted to demonstrate whether hydrogen-rich saline (HRS) has a neuroprotective effect on retinal ischemia reperfusion (RIR) injury through inhibition of PARP-1 activation. RIR was induced by transient elevation of intraocular pressure in rats. HRS (5 ml/kg) was administered peritoneally every day from the beginning of reperfusion in RIR rats until the rats were sacrificed. Retinal damage and cell death was determined using hematoxylin and eosin and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. DNA oxidative stress was evaluated by immunofluorescence staining of 8-hydroxy-2-deoxyguanosine. In addition, the expression of PARP-1 and caspase-3 was investigated by western blot analysis and/or immunohistochemical staining. The results demonstrated that HRS administration improved morphological alterations and reduced apoptosis following RIR injury. Furthermore, the present study found that HRS alleviated DNA oxidation and PARP-1 overactivation in RIR rats. HRS can protect RIR injury by inhibition of PARP-1, which may be involved in DNA oxidative stress and caspase-3-mediated apoptosis.

Hydrogen gas inhibits high-mobility group box 1 release in septic mice by upregulation of heme oxygenase 1

BACKGROUND

Sepsis is a potentially fatal whole-body inflammation caused by severe infection. Hydrogen gas (H2) is effective for treating sepsis. In this study, we hypothesized that the protective function of H2 in mice with septic lung injury occurred through the activation of heme oxygenase 1 (HO-1) and its upstream regulator nuclear factor-erythroid 2 p45-related factor 2 (Nrf2).

MATERIALS AND METHODS

Male institute of cancer research mice were subjected to sepsis by cecal ligation and puncture (CLP) with the presence or absence of H2. Beginning at 1 and 6 h after CLP or sham operation, respectively, 2% H2 was inhaled for 1 h. We intraperitoneally injected the HO-1 inhibitor zinc protoporphyrin IX (40 mg/kg) 1 h before CLP. To assess the severity of septic lung injury, we observed the 7-d survival rate, wet/dry weight ratio of lung, lung histopathologic score, oxygenation index, and so forth. Serum and homogenates from the lung, liver, and kidney were acquired for measuring the levels of high-mobility group box 1 (HMGB1) at 6, 12, and 24 h after CLP or sham operation. Furthermore, the protein and messenger RNA expression of Nrf2, HO-1, and HMGB1 was measured at 6, 12, and 24 h.

RESULTS

Septic mice had a lower survival rate and more severe lung injury compared with the sham group. However, therapy with H2 increased the survival rate and alleviated the severity of lung injury, reduced the HMGB1 level, and increased the HO-1 and Nrf2 levels in septic mice. Moreover, the HO-1 inhibitor zinc protoporphyrin IX significantly eliminated the protective effect of H2 on septic lung injury.

CONCLUSIONS

H2 plays a significant role in regulating the release of the inflammatory cytokine HMGB1 in septic mice, which is partially mediated through the activation of HO-1 as a downstream molecule of Nrf2.

Synthesis of well dispersed polymer grafted metal–organic framework nanoparticles

We prepared novel polymer grafted MOF nanoparticles for the first time with excellent water dispersity and significantly enhanced catalytic effect.

[Protective effects of inhaled hydrogen gas on cognitive function in mice with sepsis-associated encephalopathy]

OBJECTIVE

To evaluate protective effects of inhaled hydrogen gas (H2) on cognitive function in a murine model of sepsis-associated encephalopathy (SAE).

METHODS

A total of 84 male ICR mice, weighing 20-25 g, aged 6-8 weeks, were randomly divided into 4 groups of sham, sham+H2, sepsis and sepsis+H2. Sepsis was established by cecal ligation and puncture (CLP). Mice in sham+H2 and sepsis+H2 groups received 2% H2 inhalation for 1 h at 1 h and 6 h after sham operation or CLP operation respectively. The changes of neurological function and neuronal damage in hippocampal CA1 region were observed at 24 h post-operation. The activities of superoxide dismutase (SOD) and catalase (CAT) and the levels of malondialdehyde (MDA) and 8-iso-prostaglandin F2α (8-iso-PGF2α) in sera and hippocampus were detected at 24 h post-operation. The changes of cognitive function were observed by Y-maze test and fear conditional test at days 3 to 14 post-operation.

RESULTS

Compared with sham group, the neurological function significantly declined and neurons in hippocampal CA1 region were significantly damaged; the activities of SOD and CAT markedly decreased while the levels of MDA and 8-iso-PGF2α markedly increased in sera and hippocampus; the time in new zone and the percentage of freezing time dramatically decreased at days 3 to 14 post-operation in sepsis group (P < 0.05) . Compared with sepsis group, neurological function significantly improved and damaged neurons in hippocampal CA1 region significantly reduced; the activities of SOD and CAT markedly increased and the levels of MDA and 8-iso-PGF2α markedly decreased in sera and hippocampus; the time in new zone and the percentage of freezing time dramatically increased at days 3 to 14 post-operations in sepsis+H2 group (P < 0.05).

CONCLUSION

H2 inhalation can significantly alleviate neuronal damage and improve cognitive dysfunction in CLP-induced SAE mice. And it is probably associated with the increased activities of antioxidant enzymes and the reduced levels of oxidative products.

[The role of Nrf2 in the hydrogen treatment for intestinal injury caused by severe sepsis]

OBJECTIVE

To investigate the role of Nrf2 on hydrogen treatment for intestinal injury caused by severe sepsis.

METHODS

152 male ICR mice were randomly divided into four groups: sham operation group, hydrogen control group, sepsis group, and hydrogen treatment group, each n=38. Sepsis model was reproduced by cecal ligation and puncture (CLP). The mice in sham operation group and hydrogen control group did not receive CLP, and the operative procedure was the same as follows. The mice in hydrogen control group and hydrogen treatment group received 1-hour inhalation of 2% hydrogen 1 hour and 6 hours after sham operation or CLP. Twenty animals in each group were selected and observed for 7-day survival rate.Eighteen animals in each group were selected and sacrificed at 6, 12 and 24 hours after CLP. The intestinal tissues were obtained to determine the expression of Nrf2 and high mobility group B1 (HMGB1) protein by Western Blot, and the expression of Nrf2 mRNA by reverse transcription-polymerase chain reaction (RT-PCR). The middle portion of jejunum was obtained to evaluate the degree of septic injury by light microscope after hematoxylin and eosin (HE) staining.

RESULTS

There was no statistical significance in variables between sham operation group and hydrogen control group. Compared with sham operation group, the 7-day survival rate was significantly decreased in sepsis group (0 vs. 100%, P<0.05); compared with sepsis group, the 7-day survival rate was significantly increased in hydrogen treatment group (55% vs. 0, P<0.05). Compared with sham operation group, the expression of Nrf2 protein (gray value) and Nrf2 mRNA were up-regulated in sepsis group at 6, 12 and 24 hours after CLP (Nrf2 protein 6 hours: 1.973 ± 0.350 vs. 1.000 ± 0.000, t=4.411, P=0.002; 12 hours: 2.367 ± 0.186 vs. 1.000 ± 0.000, t=10.210, P=0.000; 24 hours: 2.517 ± 0.280 vs. 1.000 ± 0.000, t=9.521, P=0.000; Nrf2 mRNA 6 hours: 1.606 ± 0.271 vs. 1.000 ± 0.000, t=3.631, P=0.002; 12 hours: 1.692 ± 0.399 vs. 1.000 ± 0.000, t=3.233, P=0.005; 24 hours: 1.784 ± 0.341 vs. 1.000 ± 0.000, t=3.894, P=0.001), and it was also the expression of HMGB1 (gray value) at 24 hours after CLP operation (1.507 ± 0.220 vs. 1.000 ± 0.000, t=3.948, P=0.004). Compared with sepsis group, the expression of Nrf2 protein and Nrf2 mRNA in intestines were up-regulated at 6, 12 and 24 hours after CLP in hydrogen treatment group (Nrf2 protein 6 hours: 2.583 ± 0.395 vs. 1.973±0.350, t=2.765, P=0.024; 12 hours: 2.725 ± 0.235 vs. 2.367 ± 0.186, t=2.674, P=0.028; 24 hours: 2.930 ± 0.212 vs. 2.517 ± 0.280, t=2.595, P=0.032; Nrf2 mRNA 6 hours: 2.008 ± 0.400 vs. 1.606±0.271, t= 2.405, P=0.029; 12 hours: 2.188 ± 0.475 vs. 1.692 ± 0.399, t= 2.317, P=0.034; 24 hours: 2.333 ± 0.406 vs. 1.784 ± 0.341, t= 2.728, P=0.015). Compared with sepsis group, the expression of HMGB1 was down-regulated significantly at 24 hours after CLP in hydrogen treatment group (1.147 ± 0.152 vs. 1.507 ± 0.220, t=2.805, P=0.023). HE staining showed that there was significantly aggravated intestinal pathological injury in the mice of sepsis group; compared with sepsis group, the pathology was significantly less marked in hydrogen treatment group.

CONCLUSIONS

Through activation of Nrf2-antioxidant response element (ARE) pathway, hydrogen may increase the level of Nrf2, which is a kind of protective protein, in the intestine of mice, thus decreases the level of late pro-inflammatory factor, HMGB1, and it may protect the intestinal tissues in septic mice and increase the survival rate significantly.

Mixed Nipple Infections Caused by Variant of BPV3 and a Putative New Subtype of BPV in Cattle

Bovine papilloma is a chronic and proliferative skin and mucosal wart caused by Bovine papillomavirus (BPV). In June, 2013, a leaf-and flat-shaped wart disease was observed on the nipple skins in a cattle farm in Xinjiang. To diagnose the disease, we collected the diseased skins for pathological biopsy and DNA analysis by PCR amplification using a pair of degenerate primers FAP59 and FAP64. Sequencing and phylogenetic analysis showed that the infection was caused by a variant of BPV3 and putatively a new subtype of BPV (BPV/CHI-SW1, belonging to the Xi papillomavirus genus). This is the first report of mixed infection caused by variant of BPV3 and BPV (putatively new subtype) in China, and would be of importance for the molecular epidemiological study of the disease.

A novel decoy receptor fusion protein for FGF-2 potently inhibits tumour growth

BACKGROUND

Antiangiogenic therapies have been proven effective in cancer treatment. Fibroblast growth factor-2 (FGF-2) has been functionally implicated in tumour angiogenesis and is an important target of antiangiogenic therapies. The aim of this work was to develop a novel FGF-2 inhibitor for cancer therapy.

METHODS

Eleven fusion proteins were developed by fusing various truncated extracellular regions of FGFR1 with the Fc region of IgG1. The optimal decoy receptor fusion protein with the highest binding affinity for FGF-2 was identified by an FGF-2-binding assay and its potential antitumour effects were investigated.

RESULTS

We obtained a soluble decoy receptor fusion protein with the highest binding activity for FGF-2, named FGF-Trap. Fibroblast growth factor-Trap significantly abolished FGF-2-stimulated activation of FGF signalling as demonstrated by its suppression of FGF-2-mediated phosphorylation of Erk1/2 and Akt, upregulation of cyclins D1 and E and the increase in mRNA levels of vascular endothelial growth factor R1 and R2 (VEGFR1 and VEGFR2). Furthermore, FGF-Trap effectively suppressed FGF-2-induced proliferation and migration of human umbilical vein endothelial cells (HUVECs) in vitro. Most importantly, FGF-Trap potently inhibited tumour growth and angiogenesis in Caki-1 and A549 xenograft models in vivo.

CONCLUSIONS

Fibroblast growth factor-Trap potently inhibits tumour growth by blocking FGF-2 signalling pathways and could be an effective therapeutic agent for cancer patients.

GOLPH3 is a novel marker of poor prognosis and a potential therapeutic target in human renal cell carcinoma

Background:

Golgi phosphoprotein 3 (GOLPH3) has been reported to be involved in the development of several human cancers. The present study was conducted to investigate the expression of GOLPH3 and its prognostic significance in renal cell carcinoma (RCC). Meanwhile, the function of GOLPH3 in human RCC was further investigated in cell culture models.

Methods:

Expression of GOLPH3 was examined in 43 fresh RCC tissues and paired adjacent normal renal tissues by real-time quantitative PCR and western blotting. Immunohistochemistry for GOLPH3 was performed on additional 218 RCC tissues. The clinical significance of GOLPH3 expression was analysed. Downregulation of GOLPH3 was performed using small-interfering RNA (siRNA) in Caki-1 and 786-O cells with high abundance of GOLPH3, and the effects of GOLPH3 silencing on cell proliferation, migration, invasion in vitro, and tumour growth in vivo were evaluated.

Results:

Expression of GOLPH3 was upregulated in the majority of the RCC clinical tissue specimens at both mRNA and protein levels. Clinicopathological analysis showed that GOLPH3 expression was significantly correlated with T stage (P<0.001), lymph-node status (P=0.003), distant metastasis (P<0.001), tumour-node-metastasis (TNM) stage (P<0.001), and Fuhman grade (P=0.001). Expression of GOLPH3 was inversely correlated with both overall and recurrence-free survival of RCC patients. Multivariate analysis showed that GOLPH3 expression was an independent prognostic indicator for patient's survival. Knockdown of the GOLPH3 expression reduced cell proliferation, anchorage-independent growth, migration, invasion, and tumour growth in xenograft model mice.

Conclusions:

These results suggest that GOLPH3 expression is likely to have important roles in RCC development and progression, and that GOLPH3 is a prognostic biomarker and a promising therapeutic target for RCC.

Involvement of the blood-brain barrier opening in cognitive decline in aged rats following orthopedic surgery and high concentration of sevoflurane inhalation

The underlying causes of postoperative cognitive decline (POCD) in old patients remained unelucidated, and there are little descriptions on mechanisms associated with the blood-brain barrier (BBB) disruption during POCD. We therefore tested the effects of orthopedic surgery with different concentrations of sevoflurane for 2 h on the behavior test and the BBB permeability in aged rats. 18-month rats were divided into control group and surgical group with propofol anesthesia (0.7 mgkg(-1) min(-1)) and 1.0 MAC, 1.3 MAC, and 1.5 MAC sevoflurane inhalation for 2 h. We assessed their cognitive function via Y-maze and fear conditioning test on day 1, 3, and 7 after experiments. Animals were then assigned to control group, propofol (2 h, 0.7 mgkg(-1) min(-1)) group, surgery plus propofol group and surgery plus 1.5 MAC sevoflurane inhalation for 2h. Their hippocampal BBB permeability was detected with Evans blue quantification. Alterations of tight junctions in hippocampus were measured with occludin and claudin-5 western blot. Then we assessed matrix metalloproteinase-2,9 (MMP-2,9) via western blot and immunohistochemistry staining at day 1, 3, 7, and 14 after experiments. Surgery impaired cognitive function and increased Evans blue leakage into the hippocampus in aged rats while 2 h of 1.5 MAC sevoflurane inhalation potentiated these effects. Surgery induced occludin protein expression decreases and MMP-2,9 proteins increase and these influences can be enhanced by high concentration of sevoflurane inhalation. In conclusion, 1.5 MAC sevoflurane for 2 h exacerbated cognitive impairment induced by orthopedic surgery in aged rats and the breach in BBB may be involved in this process.

Inhibition of glycogen synthase kinase-3β prevents remifentanil-induced hyperalgesia via regulating the expression and function of spinal N-methyl-D-aspartate receptors in vivo and vitro

A large number of experimental and clinical studies have confirmed that brief remifentanil exposure can enhance pain sensitivity presenting as opioid-induced hyperalgesia (OIH). N-methyl-D-aspartate (NMDA) receptor antagonists have been reported to inhibit morphine analgesic tolerance in many studies. Recently, we found that glycogen synthase kinase-3β (GSK-3β) modulated NMDA receptor trafficking in a rat model of remifentanil-induced postoperative hyperalgesia. In the current study, it was demonstrated that GSK-3β inhibition prevented remifentanil-induced hyperalgesia via regulating the expression and function of spinal NMDA receptors in vivo and in vitro. We firstly investigated the effects of TDZD-8, a selective GSK-3β inhibitor, on thermal and mechanical hyperalgesia using a rat model of remifentanil-induced hyperalgesia. GSK-3β activity as well as NMDA receptor subunits (NR1, NR2A and NR2B) expression and trafficking in spinal cord L4-L5 segments were measured by Western blot analysis. Furthermore, the effects of GSK-3β inhibition on NMDA-induced current amplitude and frequency were studied in spinal cord slices by whole-cell patch-clamp recording. We found that remifentanil infusion at 1 μg·kg(-1)·min(-1) and 2 μg·kg(-1)·min(-1) caused mechanical and thermal hyperalgesia, up-regulated NMDA receptor subunits NR1 and NR2B expression in both membrane fraction and total lysate of the spinal cord dorsal horn and increased GSK-3β activity in spinal cord dorsal horn. GSK-3β inhibitor TDZD-8 significantly attenuated remifentanil-induced mechanical and thermal hyperalgesia from 2 h to 48 h after infusion, and this was associated with reversal of up-regulated NR1 and NR2B subunits in both membrane fraction and total lysate. Furthermore, remifentanil incubation increased amplitude and frequency of NMDA receptor-induced current in dorsal horn neurons, which was prevented with the application of TDZD-8. These results suggest that inhibition of GSK-3β can significantly ameliorate remifentanil-induced hyperalgesia via modulating the expression and function of NMDA receptors, which present useful insights into the mechanistic action of GSK-3β inhibitor as potential anti-hyperalgesic agents for treating OIH.

Prognostic and diagnostic significance of annexin A2 in colorectal cancer

AIM

Annexin A2 (ANXA2) is known to be a tumourigenic molecule and is highly expressed in colorectal cancer (CRC). Its diagnostic and prognostic value is not fully understood. This study was designed to investigate the relationship between ANXA2 expression, clinicopathological characteristics, tumour recurrence and survival.

METHOD

Immunohistochemical staining was used to evaluate ANXA2 expression in 150 matched samples from patients with CRC. Overall survival and recurrence were determined by Kaplan-Meier analysis. The Cox proportional hazards model was used to determine independent factors contributing to survival and recurrence. Receiver operating characteristic (ROC) curve and liner correlation analysis were used to estimate the sensitivity and specificity of ANXA2 expression for clinical diagnosis.

RESULTS

ANXA2 was found to be strongly expressed in poorly differentiated tumours (P < 0.001), late stage (P = 0.020) and lymph node positivity (P = 0.002). ANXA2 expression was significantly related to recurrence (P < 0.001) and survival (P = 0.002). The Cox proportional hazards model indicated that ANXA2 expression [P < 0.001, hazard ratio (HR) = 1.366, 95% CI 1.232-1.515] and tumour location (P = 0.039, HR = 1.891, 95% CI 1.034-3.456) were independent factors in predicting overall survival while ANXA2 expression (P < 0.001, HR = 1.445, 95% CI 1.222-1.709) were independent factors predicting recurrence. Receiver operating characteristic (ROC) (AUC = 0.768, 95% CI = 0.642-0.894) and liner correlation analysis suggested that ANXA2 was suitable for the clinical diagnosis of CRC.

CONCLUSION

These results indicate that ANXA2 is a biomarker with diagnostic and prognostic potential for patients with CRC.

Expression of c-Fos and c-Jun in adjacent cervical spinal cord segments following C7 nerve root rhizotomy in rats: Indication of a neural pathway between adjacent cervical spinal cord segments

Cervical radiculopathy is a common disease in clinical practice. However, the symptoms are not confined to the affected spinal cord segment indicated by magnetic resonance imaging (MRI) findings. In the present study, we measured c-Fos and c-Jun expression in ipsilateral and adjacent cervical spinal cord segments following C₇ nerve root rhizotomy, to determine whether there is a neural pathway between adjacent cervical spinal cord segments. Forty-eight adult male Wistar rats were randomly divided into two groups: the C₇ rhizotomy group (rhizotomy group, n=24) and the sham-operated group (sham group, n=24). The right C₇ nerve root was completely cut off in the rhizotomy group, while it was exposed but not cut in the sham group. The expression of c-Fos and c-Jun in cervical spinal cord segments was detected by immunohistochemistry at 2 and 4 h after surgery. We observed that the number of c-Fos- and c-Jun-positive neurons in ipsilateral C_5–7 segments were significantly increased at 2 and 4 h after C₇ nerve root rhizotomy (P<0.05 vs. the sham group). The location of c-Fosand c-Jun-positive neurons in C_5–7 gray matter was similar in the rhizotomy and sham groups, which was mainly in lamina IX of the anterior horn and laminae I–II of the dorsal horn of the spinal cord. However, the number of c-Fos- and c-Jun-positive neurons in the C_5–7 gray matter was significantly reduced at 4 h after surgery compared with the number 2 h after surgery. The location of c-Fos- and c-Jun-positive neurons at 4 h was similar with that at 2 h. Therefore, there may be a neural pathway between ipsilateral adjacent cervical spinal cord segments. This may be one possible explanation as to why the radicular symptoms of cervical radiculopathy are not confined to the affected spinal cord segment shown by MRI.

Beneficial effects of hydrogen-rich saline against spinal cord ischemia-reperfusion injury in rabbits

Hydrogen-rich saline (HS) is reported to be a new therapeutic agent in ischemia-reperfusion (I/R)-induced organ damage. The present study was designed to investigate the beneficial effects of HS against spinal cord I/R injury and its associated mechanisms. Spinal cord ischemia was induced by infrarenal aortic occlusion for 20min in male New Zealand white rabbits. Different doses of HS were intravenously (i.v.) administered at 5min before or after the beginning of reperfusion. Moreover, the roles of mitochondrial ATP-sensitive potassium channels (mitoKATP), oxidative stress, inflammatory cytokines and apoptosis was assessed. Here, we found that I/R-challenged rabbits exhibited significant spinal cord injury characterized by the decreased numbers of normal motor neurons and hind-limb motor dysfunction, which was significantly ameliorated by 5mL/kg and 10mL/kg HS treatment before reperfusion or 10mL/kg HS treatment after reperfusion. However, the protective effects of HS treatment in spinal cord I/R injury were partially abolished by the selective mitoKATP channel blocker 5-hydroxydecanoate (5-HD). Moreover, we showed that the beneficial effects of 10mL/kg HS treatment against spinal cord I/R damage were associated with the decreased levels of oxidative products [8-iso-prostaglandin F2α (8-iso-PGF2α) and malondialdehyde (MDA)] and pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and high-mobility group box 1 (HMGB1)], as well as the increased activities of antioxidant enzymes [superoxide dismutase (SOD) and catalase (CAT)] in serum at 6h, 12h, 24h, 48h and 72h after reperfusion and in spinal cord at 72h after reperfusion. Furthermore, HS treatment (10mL/kg) reduced caspase-3 activity in the spinal cord of this model. Thus, HS may be an effective therapeutic agent for spinal cord I/R injury via activation of mitoKATP channels as well as reduction of oxidative stress, inflammatory cytokines and apoptosis.

Patients get more long-term benefit from central pancreatectomy than distal resection: a meta-analysis

AIMS

Central pancreatectomy (CP) protects more normal pancreatic parenchyma than distal pancreatectomy (DP), but the safety, feasibility and long-term benefit of CP are inconclusive. This meta-analysis aims to ascertain the relative merits of CP.

METHODS

A systematic literature research was performed to identify comparative studies on CP and DP. Perioperative and long-term outcomes constituted the end points. Pooled risk ratios (RR) and weighted mean differences (WMD) with 95% confidence intervals (95% CI) were calculated using either fixed effects or random effects model.

RESULTS

Nine studies with 735 patients were included in this meta-analysis. Although CP cost more operative time than DP, the two groups had no significant differences in the volume of intraoperative blood loss, rate of intraoperative blood transfusion and length of postoperative hospital stay. According to the postoperative outcomes, although the CP group had higher overall complication rate (Fixed effects model; RR: 1.30; 95% CI: 1.05-1.62; P < 0.05) as well as overall pancreatic fistula rate (Fixed effects model; RR: 1.58; 95% CI: 1.20-2.08; P < 0.05), the two groups did not differ significantly in the fateful surgical complications such as clinically significant pancreatic fistula (Grades B and C), postoperative bleeding, reoperation and intra-abdominal effusion/abscess. Furthermore, the perioperative mortality rate was comparable between the two groups. During the follow-up period, the patients after DP were more likely to suffer pancreatic exocrine insufficiency (Fixed effects model; RR: 0.53; 95% CI: 0.32-0.86; P < 0.05) and endocrine impairment (Fixed effects model; RR: 0.19; 95% CI: 0.11-0.33; P < 0.05).

CONCLUSION

CP was still an acceptable and feasible procedure, especially when considering the postoperative pancreatic function preservation ability by CP.

Plasma specific miRNAs as predictive biomarkers for diagnosis and prognosis of glioma

Objective

Glioblastoma multiforme (GBM) is a highly malignant brain tumor with a poor prognosis. MicroRNAs (miRNAs) are a class of small non-coding RNAs, approximately 21–25 nucleotides in length. Recently, some researchers have demonstrated that plasma miRNAs are sensitive and specific biomarkers of various cancers. The primary aim of the study is to investigate whether miRNAs present in the plasma of GBM patients can be used as diagnostic biomarkers and are associated with glioma classification and clinical treatment.

Materials and Methods

Plasma samples were attained by venipuncture from 50 patients and 10 healthy donors. Plasma levels of miRNAs were determined by real-time quantitative polymerase chain reaction.

Results

The plasma levels of miR-21, miR-128 and miR-342-3p were significantly altered in GBM patients compared to normal controls and could discriminate glioma from healthy controls with high specificity and sensitivity. However, these three miRNAs were not significantly changed in patients with other brain tumors such as meningioma or pituitary adenoma. Furthermore, the plasma levels of these three miRNAs in GBM patients treated by operation and chemo-radiation almost revived to normal levels. Finally, we also demonstrated that miR-128 and miR-342-3p were positively correlated with histopathological grades of glioma.

Conclusions

These findings suggest that plasma specific miRNAs have potential use as novel biomarkers of glioma and may be useful in clinical management for glioma patients.

Cytokine-induced apoptosis in transformed murine fibroblasts involves synthesis of endogenous nitric-oxide

The purpose of this study was to determine whether the synthesis of endogenous nitric oxide (NO) is involved in the apoptosis of murine L929 transformed fibroblasts. L929 parental cells and L929 cells selected for resistance to tumor necrosis factor (TNF-alpha) were incubated in vitro with various concentrations of TNF-alpha, interleukin-1, and lipopolysaccharide (LPS) in the presence or absence of mouse interferon-gamma (IFN-gamma). The combination of subthreshold concentrations of IFN-gamma with the cytokines or LPS produced significant cell death within 48 h incubation. This cell death was associated with the induction of high levels of NO. Both cell death and NO production were significantly inhibited by the addition of N(G)-methyl-L-arginine (NMA), a specific inhibitor of nitric oxide synthase. The synergistic cytotoxicity was associated with extensive internucleosomal DNA fragmentation. NMA also inhibited this process. These data demonstrate the involvement of endogenous NO in cytokine-induced apoptosis of transformed cells.

Protective effects of hydrogen-rich saline in a rat model of permanent focal cerebral ischemia via reducing oxidative stress and inflammatory cytokines

Hydrogen gas (H(2)) as a new medical gas exerts organ-protective effects through regulating oxidative stress, inflammation and apoptosis. In contrast to H(2), hydrogen-rich saline (HS) may be more suitable for clinical application. The present study was designed to investigate whether HS can offer a neuroprotective effect in a rat model of permanent focal cerebral ischemia and what mechanism(s) underlies the effect. Sprague-Dawley rats were subjected to permanent focal cerebral ischemia induced by permanent middle cerebral artery occlusion (pMCAO). Different doses of HS or normal saline were intraperitoneally administered at 5min after pMCAO or sham operation followed by injections at 6h, 12h and 24h. Here, we found that HS treatment significantly reduced infarct volume and improved neurobehavioral outcomes at 24h, 48h and 72h after pMCAO operation in a dose-dependent manner (P<0.05). Moreover, we found that HS treatment dose-dependently increased the activities of endogenous antioxidant enzymes (SOD and CAT) as well as decreased the levels of oxidative products (8-iso-PGF2α and MDA) and inflammatory cytokines (TNF-α and HMGB1) in injured ipsilateral brain tissues at 6h, 12h and 24h after pMCAO operation (P<0.05). Thus, hydrogen-rich saline dose-dependently exerts a neuroprotective effect against permanent focal cerebral ischemia, and its beneficial effect is at least partially mediated by reducing oxidative stress and inflammation. Molecular hydrogen may be an effective therapeutic strategy for stroke patients.

Hyperbaric oxygen preconditioning protects cortical neurons against oxygen-glucose deprivation injury: role of peroxisome proliferator-activated receptor-gamma

Ischemic stroke is one of the leading causes of mortality and disability worldwide. Our previous studies have shown that hyperbaric oxygen (HBO) preconditioning can afford significant neuroprotection against cerebral ischemia-reperfusion (I/R) injury in rats. However, it is still unknown whether HBO preconditioning can directly protect primary cultured cortical neurons against oxygen-glucose deprivation (OGD). Peroxisome proliferator-activated receptor-gamma (PPAR γ) plays a central role in the regulation of apoptosis, oxidative stress and inflammation as well as affords significant neuroprotection against cerebral I/R injury. 15-deoxy-∆(12,14)-prostaglandin J(2) (15d-PGJ(2)) is an endogenous ligand with a high affinity for PPAR γ. Recently, some studies demonstrate that activation of PPAR γ mediates lipopolysaccharide and anesthetic preconditioning. In the present study, we firstly found that OGD exposure caused the significant damage of cultured cortical neurons evaluated by cell viability, lactate dehydrogenase (LDH) release and caspase-3 activity, which were significantly ameliorated by HBO preconditioning. Furthermore, HBO preconditioning significantly increased the levels of PPAR γ mRNA and protein, PPAR γ DNA binding activity, 15d-PGJ(2) and antioxidant enzymatic activities in primary cultured cortical neurons with OGD exposure. Moreover, PPAR γ antagonist GW9662 dose-dependently abolished the protection of HBO preconditioning in OGD-exposed neurons. GW9662 blocked the increase of PPAR γ DNA binding activity and antioxidant enzymatic activities, but did not influence the 15d-PGJ(2) level in OGD-exposed neurons with HBO preconditioning. However, the cyclooxygenase (COX)-2 inhibitor NS-398 blocked the production of 15d-PGJ(2) in OGD-exposed neurons with HBO preconditioning. In addition, 15d-PGJ(2) preconditioning could also protect cultured neurons against OGD injury. These results demonstrate that HBO preconditioning has directly beneficial effects on ODG-exposed cortical neurons by the activation of PPAR γ subsequent to the production of 15d-PGJ(2), which in turn increases the downstream antioxidant enzymatic activities.

Inhalation of hydrogen gas attenuates cisplatin-induced ototoxicity via reducing oxidative stress

OBJECTIVE

Cisplatin, an anticancer drug used extensively to treat a broad range of tumors, has strong ototoxic side effects induced by reactive oxygen species (ROS). Recently, it has been reported that hydrogen gas (H(2)) is a new antioxidant by selectively reducing hydroxyl radical, the most cytotoxic ROS. The present study was designed to investigate whether H(2) treatment is beneficial to cisplatin-induced ototoxicity via reducing oxidative stress.

METHODS

The animals were intraperitoneally given a 30 min infusion of 16 mg/kg cisplatin or the same volume of saline. H(2) treatment was given twice with 2% H(2) inhalation for 60 min starting at 1h and 6h after cisplatin or saline injection, respectively. The hearing status of all animals was evaluated by auditory brainstem responses (ABR). The hair cell damage was observed by phalloidin staining. In addition, the levels of oxidative products in serum and cochlear tissue were measured.

RESULTS

We found that H(2) treatment significantly attenuated cisplatin-induced hearing loss evaluated by click-evoked and tone burst ABR threshold. Furthermore, histological analysis revealed that 2% H(2) treatment significantly alleviated cisplatin-induced hair cell damage in the organ of corti. In addition, cisplatin significantly increased the levels of malondialdehyde (MDA) and 8-iso-prostaglandin F2α (8-iso-PGF2α) in serum and cochlear tissue, which was attenuated by H(2) treatment.

CONCLUSION

These results demonstrate that H(2) is beneficial to cisplatin-induced ototoxicity via reducing oxidative stress. Therefore, H(2) has potential for improving the quality of life of patients during chemotherapy by efficiently mitigating the cisplatin ototoxicity.

Beneficial effects of hydrogen gas against spinal cord ischemia-reperfusion injury in rabbits

Recently, hydrogen gas (H₂) is reported to be a new therapeutic agent in organ damage induced by ischemia-reperfusion (I/R). The present study was designed to investigate the beneficial effects of H₂ against spinal cord I/R injury and its associated mechanisms. Spinal cord ischemia was induced by infrarenal aortic occlusion for 20 min in male New Zealand white rabbits. Treatment with 1%, 2% or 4% H₂ inhalation was given from 10 min before reperfusion to 60 min after reperfusion (total 70 min). Here, we found that I/R-challenged animals showed significant spinal cord damage characterized by the decreased numbers of normal motor neurons and hind-limb motor dysfunction, which was significantly improved by 2% and 4 % H₂ treatment. Furthermore, we found that the beneficial effects of H₂ treatment against spinal cord I/R injury were associated with the decreased levels of oxidative products [8-iso-prostaglandin F2α (8-iso-PGF2α) and malondialdehyde (MDA)] and pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and high-mobility group box 1 (HMGB1)], as well as increased activities of antioxidant enzymes [superoxide dismutase (SOD) and catalase (CAT)] in serum and spinal cord. In addition, H₂ treatment reduced motor neuron apoptosis in the spinal cord of this model. Thus, H₂ inhalation may be an effective therapeutic strategy for spinal cord I/R damage.

Beneficial effects of hydrogen gas in a rat model of traumatic brain injury via reducing oxidative stress

Traumatic brain injury (TBI) is a leading cause of mortality and disability among the young population. It has been shown that hydrogen gas (H(2)) exerts a therapeutic antioxidant activity by selectively reducing hydroxyl radical (OH, the most cytotoxic ROS). Recently, we have found that H(2) inhalation significantly improved the survival rate and organ damage of septic mice. In the present study, we investigated the effectiveness of H(2) therapy on brain edema, blood-brain barrier (BBB) breakdown, neurological dysfunction and injury volume in TBI-challenged rats. In addition, we investigated the effects of H(2) treatment on the changes of oxidative products and antioxidant enzymes in brain tissue of TBI-challenged rats. Hydrogen treatment was given by exposure to 2% H(2) from 5 min to 5h after sham or TBI operation, respectively. Here, we found that TBI-challenged rats showed significant brain injuries characterized by the increase of BBB permeability, brain edema and lesion volume as well as neurological dysfunction, which was significantly attenuated by 2% H(2) treatment. In addition, we found that the decrease of oxidative products and the increase of endogenous antioxidant enzymatic activities in the brain tissue may be associated with the protective effects of H(2) treatment in TBI-challenged rats. The present study supports that H(2) inhalation may be a more effective therapeutic strategy for patients with TBI.

Performance and fouling characteristics of a submerged anaerobic membrane bioreactor for kraft evaporator condensate treatment

Submerged anaerobic membrane bioreactor (SAnMBR) technology was studied for kraft evaporator condensate treatment at 37 +/- 1 degrees C over a period of 9 months. Under tested organic loading rates of 1-24 kg COD/m3/day, a chemical oxygen demand (COD) removal efficiency of 93-99% was achieved with a methane production rate of 0.35 +/- 0.05 L methane/g COD removed and a methane content of 80-90% in produced biogas. Bubbling of recycled biogas was effective for in-situ membrane cleaning, depending on the biogas sparging rate used. The membrane critical flux increased and the membrane fouling rate decreased with an increase in the biogas sparging rate. The scanning electron microscopy images showed membrane pore clogging was not significant and sludge cake formation on the membrane surface was the dominant mechanism of membrane fouling. The results suggest that the SAnMBR is a promising technology for energy recovery from kraft evaporator condensate.

Treatment of kraft evaporator condensate using a thermophilic submerged anaerobic membrane bioreactor

The feasibility of using a thermophilic submerged anaerobic membrane bioreactor (SAnMBR) for kraft evaporator condensate treatment was studied at 55+/-1 degrees C over 6.5 months. Under tested organic loading rate of 1-7 kg COD/m(3) day, a soluble COD removal efficiency of 85-97% was obtained. The methane production rate was 0.35+/-0.1 L methane/g COD and the produced biogas was of excellent fuel quality with 80-90% methane. A higher membrane fouling rate was related to the presence of a larger portion of fine colloidal particles (1-10 mum). The thermophilic SAnMBR was sensitive to the presence of toxic compounds in feed and unexpected pH probe failure (leading to a higher pH). Feed toxic shock caused sludge deflocculation and thus deteriorated membrane performance. Operating the reactor as a conventional anaerobic reactor to waste some of the fine flocs in treated effluent during the start-up process was an effective strategy to reduce membrane fouling. The experimental results from this study indicate that treatment of kraft evaporator condensate is feasible in terms of COD removal and biogas production using thermophilic SAnMBRs but pre-treatment may be needed to remove toxic sulfur compounds and membrane fouling caused by the large portion of fine particles may be a challenge.

Sludge properties and their effects on membrane fouling in submerged anaerobic membrane bioreactors (SAnMBRs)

Two submerged anaerobic membrane bioreactors (SAnMBRs) (thermophilic vs. mesophilic) were operated for a period of 3.5 months with kraft evaporator condensate at a feed chemical oxygen demand of 10,000 mg/L. The results show that the filtration behavior of the two systems was significantly different. The filtration resistance in the thermophilic SAnMBR was about 5-10 times higher than that of the mesophilic system when operated under similar hydrodynamic conditions. Comparison of sludge properties and cake layer structure from the two systems was made to elucidate major factors governing the different filtration characteristics. There were more soluble microbial products (SMP) and biopolymer clusters (BPC) produced and a larger portion of fine flocs (<15 microm) in the thermophilic SAnMBR. Analysis of bound extracellular polymeric substances (EPS) showed that the thermophilic sludge had a higher protein/polysaccharide ratio in EPS, as compared to that in the mesophilic sludge. A series of analyses, including Fourier transform infrared (FTIR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and particle size analyzer showed that the cake layer formed in the thermophilic SAnMBR contained higher levels of both organic and inorganic foulants, smaller particle sizes, and especially, a denser and more compact sludge cake structure. These results indicate that floc size, SMP, BPC, bound EPS as well as cake layer structure are the major factors governing membrane fouling in SAnMBR systems.