Investigation on the Nanopore Heterogeneity in Coals and its Influence on Methane Adsorption: A Multifractal Theory Study.

Coalbed methane (CBM) reservoirs constitute a distinct class of dense organic rocks characterized by extremely low porosity and permeability. Conducting an in-depth investigation into pore heterogeneity assumes paramount importance for the exploration and development of CBM. This study focuses on the multifractal analysis of the pores with diameters below 300 nm in six coal samples sourced from the Junggar Basin and the Qinshui Basin in China. The analysis is based on a series of experiments involving CO2 adsorption, low-temperature N2 adsorption/desorption, and CH4 isothermal adsorption. This work delves into the influence of pore heterogeneity on gas adsorption capacity by linking the structural parameters to CH4 adsorption properties. The results indicate that both the micropores, as assessed through CO2 adsorption, and mesopores to macropores, measured via N2 adsorption, exhibit multifractal behavior. In contrast to micropores, the mesopores and macropores display stronger heterogeneity and lower connectivity. Generally, uniform and well-connected nanopores are anticipated to positively contribute to gas adsorption. However, there is a positive correlation between the Langmuir volume and the heterogeneity degree of micropores. This phenomenon is ascribed to the fact that the greater surface complexity in micropores involves a larger specific surface area and a higher abundance of adsorption sites. This research contributes to a more profound and precise comprehension of the heterogeneous pore structure within CBM reservoirs, thereby establishing a theoretical foundation for the sustainable exploitation of CBM.

The cyclic AMP (cAMP) phosphodiesterase CpdA required for growth, biofilm formation, motility and pathogenicity of Edwardsiella piscicida.

Edwardsiella piscicida is a severe fish pathogen with wide host range, causing the huge economic losses in the aquaculture industry. Cyclic adenosine monophosphate (cAMP) as an important second messenger regulates the physiological and behavioral responses to environmental cues in eukaryotic and prokaryotic. The intracellular level of cAMP for effective activity is tightly controlled by the synthesis of adenylate cyclase, excretion and degradation of phosphodiesterase. In this study, we identified and characterized a class III cAMP phosphodiesterase, named as CpdA, in the E. piscicida. To investigate the role of CpdA in the physiology and pathogenicity, we constructed the in-frame deletion mutant of cpdA of E. piscicida, TX01ΔcpdA. The results showed that TX01ΔcpdA accumulated the higher intracellular cAMP concentration than TX01, indicating that CpdA exerted the hydrolysis of cAMP. In addition, compared to the TX01, the TX01ΔcpdA slowed growth rate, diminished biofilm formation and lost motility. More importantly, pathogenicity analysis confirmed that TX01ΔcpdA significantly impaired the ability of invading the epithelial cells, reproduction in macrophages, tissues dissemination and lethality for healthy tilapias. The most of lost properties of TX01ΔcpdA were restored partially or fully by the introduction of cpdA gene. These results suggest that cpdA is required for regulation of the physiology and virulence of E. piscicida.

Analysis on methane production from various coal slime fermentations based on metagenomics.

Metagenomic sequencing technology was applied to evaluate differences in the anaerobic fermentation process of coal slimes by analyzing microbial diversity, functional activity structure, and cooperative relationship during the anaerobic fermentation of coal slimes with different coal ranks. The obtained results showed that the production of biomethane from coal slime was decreased by increasing metamorphism degree. Internal reason was higher abundance of microbial community in low rank coal slimes compared to that in high rank coal which had higher activity in the gene expression of key steps such as hydrolysis and acidification, methanation and the production of hydrogen and acetic acid. Acetic acid decarboxylation and CO2 reduction are two key pathways of methanation process. At the same time, K11261 (formylmethanofuran dehydrogenase subunit) and K01499 (methenyltetrahydromethanopterin cyclohydrolase) genes were further enriched in low rank slime systems, which enhanced the proportion of CO2 reduction in methanation pathway and was beneficial to biomethane production. Research revealed the roles of different coal slime ranks in biomethane production process and is considered as an important reference significance for further exploration of coal slime resource utilization.

Metagenomic characterization of biomethane transformation by lipid-catalyzed anaerobic fermentation of lignite.

The present study aims at using lipid in a novel way to improve the efficiency of methane production from lignite anaerobic digestion. The obtained results showed an increase by 3.13 times of the cumulative biomethane content of lignite anaerobic fermentation, when 1.8 g lipid was added. The gene expression of functional metabolic enzymes was also found to be enhanced during the anaerobic fermentation. Moreover, the enzymes related to fatty acid degradation such as long-chain Acyl-CoA synthetase and Acyl-CoA dehydrogenase were increased by 1.72 and 10.48 times, respectively, which consequently, accelerated the conversion of fatty acid. Furthermore, the addition of lipid enhanced the carbon dioxide trophic and acetic acid trophic metabolic pathways. Hence, the addition of lipids was argued to promote the production of methane from lignite anaerobic fermentation, which provided a new insight for the conversion and utilization of lipid waste.

The characteristics of solid-phase substrate during the co-fermentation of lignite and straw.

Co-fermentation of lignite and biomass has been considered as a new approach in achieving clean energy. Moreover, the study of the characteristics of solid phase in the synergistic degradation process is of great significance in revealing their synergistic relationship. Accordingly, in order to produce biogas, lignite, straw, and the mixture of the two were used as the substrates, the solid phase characteristics of which were analyzed before and after fermentation using modern analytical methods. The results revealed that the mixed fermentation of lignite and straw promoted the production of biomethane. Moreover, the ratios of C/O and C/H were found to be complementary in the co-fermentation process. Furthermore, while the relative content of C-C/C-H bonds was observed to be significantly decreased, the aromatics degree of lignite was weakened. Also, while the degree of branching increased, there found to be an increase in the content of cellulose amorphous zone, which, consequently, led to an increase in the crystallinity index of the wheat straw. Hence, the results provide a theoretical guidance for the efficient utilization of straw and lignite.

Chinese herbal compound prescriptions combined with Chinese medicine powder based on traditional Chinese medicine syndrome differentiation for treatment of chronic atrophic gastritis with erosion: a multi-center, randomized, positive-controlled clinical trial.

BACKGROUND: In this study, Chinese herbal compound prescriptions combined with Chinese medicine powder were evaluated for the treatment of chronic atrophic gastritis with erosion. METHODS: This multi-center, randomized, positive drug control clinical trial randomly assigned 216 patients with chronic atrophic gastritis with erosion to three groups: (1) control group: aluminum plus magnesium suspension thrice per day for 4 weeks; (2) test group 1: Chinese herbal compound prescriptions twice a day plus Sanqi (Panax notoginseng) powder twice a day for 4 weeks; (3) test group 2: Chinese herbal compound prescriptions twice a day plus Sanqi (Panax notoginseng) powder and Zhebeimu (Fritillaria thunbergii Miq.) powder twice a day for 4 weeks. The primary endpoint (improvement of gastric mucosal erosion; improvement of gastric mucosal pathology) and secondary endpoints (improvement of clinical symptoms scores; improvement of the patient-reported outcome [PRO] instrument for chronic gastrointestinal diseases) were assessed using endoscopy at week 4 following the treatment. Drug-related adverse events (AEs) and adverse drug reactions (ADRs) were also compared. RESULTS: The final analysis included 202 patients (control group, 63; test group 1, 69; test group 2, 70). At week 4, using within-group comparison, gastric mucosal erosion improved in each group following treatment with a significant difference (P < 0.05); there were no statistically significant differences in gastric mucosal erosion scores among the groups after treatment (P > 0.05); in terms of improvement of gastric mucosal erosion, the efficacy rate of the control group was 69.12%, the efficacy rate of the test group 1 was 73.24%, and the efficacy rate of the test group 2 was 69.01% and efficacy rate among the groups was not statistically significant (P > 0.05). As determined by acute inflammation, chronic inflammation, atrophy, intestinal metaplasia, and dysplasia, the pathological score (total score and the highest score) did not differ statistically among groups following treatment (P > 0.05); within the control group, the total scores of acute inflammation, chronic inflammation, atrophy, and intestinal metaplasia were significantly decreased (P < 0.05), but there was no significant improvement in dysplasia (P > 0.05); in the test group 1, chronic inflammation, atrophy, and intestinal metaplasia and dysplasia scores were significantly decreased (P < 0.05), but acute inflammation did not improve (P > 0.05); there was a significant reduction in the atrophy score in test group 2 (P < 0.05), but no improvement in the scores of acute inflammation, chronic inflammation, intestinal metaplasia, and dysplasia was observed (P > 0.05). Similarly, within the control group, the highest scores of acute inflammation, chronic inflammation, atrophy, and intestinal metaplasia were significantly decreased (P < 0.05), but there was no significant improvement in dysplasia (P > 0.05); there was a significant reduction in highest scores of atrophy, intestinal metaplasia, and dysplasia (P < 0.05) in test group 1, but the highest scores didn't not improve with acute inflammation and chronic inflammation (P > 0.05); there was a significant reduction in the highest atrophy score in test group 2 (P < 0.05), but no improvement in the highest scores of acute inflammation, chronic inflammation, intestinal metaplasia, and dysplasia was observed (P > 0.05). Compared to the control group, the main symptom scores and total symptom scores in the test groups were lower following treatment, with a statistically significant difference (P < 0.05); the analysis of covariance with center, erosion type, and group as factors was applied, and the comparison among the groups in dyspepsia, defecation, and total PRO instrument scores were statistically significant (P < 0.05). In the study period, AEs were reported in 3 (4.23%) patients in the test group 1 and 3 (4.41%) patients in the control group; ADRs were confirmed in 3 (4.23%) patients from the test group 1 and 2 (2.94%) from the control group. AEs and ADRs were not statistically significantly different among groups (AE, P = 0.2213; ADR, P = 0.2872). No serious AE or ADR was reported. CONCLUSIONS: This study has shown that both aluminum plus magnesium suspension and Chinese herbal compound prescriptions together with Panax notoginseng powder are capable of improving gastric mucosal erosion and reducing gastric mucosal pathological scores, and there were no statistically significant differences among the groups in primary endpoints, indicating that Chinese herbal therapy can achieve similar efficacy than antacids in terms of primary outcomes. The aluminum plus magnesium suspension is comparable to Chinese herbal therapy in improving atrophy and intestinal metaplasia, and is inferior to Chinese herbal therapy in improving dysplasia. In addition, the Chinese herbal therapy significantly outperforms the aluminum plus magnesium suspension in improving symptoms. Therefore, the overall clinical outcome of Chinese herbal compound prescriptions together with Panax notoginseng powder based on TCM syndrome patterns in the treatment of erosive gastritis is superior to that of antacids. Trial registration ChiCTR, ChiCTR-IPR-15005905. Registered 22 January 2015, https://www.chictr.org.cn/showproj.aspx?proj=10359.

Study on the Electrical Control Mechanism of Gas Occurrence in a Microscale Coal Matrix.

The study of the gas occurrence mechanism in a microscale coal matrix is the basis of coalbed methane (CBM) reservoir formation mechanism analysis and its exploration and development scheme design, which has important scientific and engineering significance. Currently, many researchers are focusing on a specific coal type to explore the macroscopic adsorption characteristics of gas occurrence. However, the research on the microscale gas-solid coupling mechanism is relatively rare and the electrical control mechanism of gas occurrence is not reported in detail. This study focuses on the electrical mechanism of microscale gas occurrence using physical simulation experiments and molecular dynamics analysis. This study clarifies the "gas adsorption-electrical properties-functional group" linkage mechanism and explores the macroscopic performance of the microscale gas occurrence mechanism using electrical properties. The study reveals the following: (1) the coal reservoirs exhibit a weak negative potential at the nanoscale, and the trends of surface potential (SP) and surface electrical charging density (SECD) are fluctuated with the degree of coal rank increases; (2) there is a good correlation between the SP, SECD values, and the relative content of functional groups; and (3) the charge density on the coal's microscopic surface influences their gas molecule attraction capacity, affecting the gas adsorption capacity of coal reservoirs at the macroscale. This study presents a theoretical foundation for establishing the molecular force field superposition mechanism of gas occurrence in microscale coal matrix and has broad application prospects in the macroscale numerical simulation of CBM development.

Mineral Characteristics of Low-Rank Coal and the Effects on the Micro- and Nanoscale Pore-Fractures: A Case Study from the Zhundong Coalfield, Northwest China.

The mineral characteristics (occurrence, type, and content) of low-rank coal and their influence on coalbed methane (CBM) reservoirs are investigated at the micro- and nanoscales. Six coal samples of three representative coalmines were used to demonstrate the uniform tectonization from the Zhundong coalfield, NW China. Based on optical microscopy and scanning electron microscopyenergy dispersive spectrum (SEM-EDS) analysis, the mineral composition and occurrence characteristics were discussed. The micro- and nanoscale reservoir characteristics in low-rank coal (pore size distribution and adsorption capability) were studied by diverse methods, including lowtemperature N2 adsorption/desorption, mercury intrusion porosimetry and CH4 isotherm adsorption analysis. The coal reservoir nuclear magnetic T2 spectra of porosity and movable fluid were obtained by combining low-field nuclear magnetic resonance (NMR) analysis, which has an advantage of determining pore fluid technology. The mineral content is highly variable (4˜16 vol.%) in the Xi Heishan prospecting area of the Qitai region. Kaolinite, goyazite, ankerite and anorthosite were microscopically observed to be filling in coal pores and microfractures, and the minerals are given priority to silicate minerals. There is a greater content of mesopores (100-1000 nm) and transition pores (10-100 nm), and they are well connected. The micropores (0-10 nm) are dominated by parallel plate, closed or wedge-shaped pores. Furthermore, the microfractures are mainly observed for types B (width ≥ 5 µm and length≤ 10 mm) and D (width<5 µm and length<300 µm). The results show that microfractures B and C (width< 5 µm and length ≥ 300 µm) are better connected, but the orientation and connectivity of type D are worse. The Langmuir volume and mesopore content decreased with increasing mineral content, which shows that the low-rank coal minerals filled some adsorption space; the reduced CBM adsorption capacity and cellular pore and intergranular pore filled with minerals affect the mesopore content. Therefore, mineral characterization significantly influences methane adsorption capacity and pore structure.

Fas signaling induces stemness properties in colorectal cancer by regulation of Bmi1.

Fas signaling promotes colorectal cancer (CRC) metastasis by inducing epithelial-mesenchymal transition (EMT). The acquisition of EMT properties in turn induces stemness but the mechanism by which Fas signaling contributes to it still remains unclear. Hence, the aim of this study was to investigate how Fas signaling regulates CRC stemness. For this purpose, soft agar assay, sphere formation assay, cell survival analysis, immunoblot, qRT-PCR, chromatin immunoprecipitation, and luciferase reporter assay were performed. Expression of FasL, Bmi1, and the miR-200c in CRC specimens was examined through immunohistochemistry, qRT-PCR, and immunoblot. In our study, Fas signaling induced stem cell properties in CRC specimens, relying on ERK1/2 MAPK pathway, with Bmi1 being mainly responsible for FasL-induced stemness. FasL treatment promoted Bmi1 expression by inhibiting miR-200c, which targets Bmi1 3'UTR region. Furthermore, FasL-induced Zeb1 binded with miR-200c promoter and inhibited its expression. Moreover, FasL-induced ß-catenin nuclear expression promoted Zeb1 expression by binding with Zeb1 promoter. GSK-3ß, which regulates ß-catenin, was inhibited by FasL-induced ERK1/2 MAPK signaling. Finally, FasL and Bmi1 expression in clinical samples increased during CRC progression, and a positive correlation between them was observed. Patients with high FasL and Bmi1 expression had a worse prognosis than patients with low expression. In conclusion, our results showed that Fas signaling can promote stemness in CRC through the modulation of Bmi1 expression via the ERK1/2 MAPK/GSK-3ß/ß-catenin/Zeb1/miR-200c axis, suggesting that Fas signaling-based cancer therapies should be administered cautiously, as the activation of this pathway not only leads to apoptosis but also induces stemness in CRC.

Small hepatocyte-like progenitor cells may be a Hedgehog signaling pathway-controlled subgroup of liver stem cells.

The present study aimed to investigate the expression levels of components of the Hedgehog signaling pathway (HH) during the proliferation of a liver stem cell subgroup, namely small hepatocyte-like progenitor cells (SHPCs). Retrorsine-treated Fisher 344 rats underwent a partial hepatectomy (PH) to induce the proliferation of SHPCs, after which reverse transcription-polymerase chain reaction (PCR), quantitative PCR, immunohistochemistry and western blot analysis were performed to analyze the expression of various components of the HH in primary SHPCs at different times points post-PH. A number of components of the HH, including Indian hedgehog (IHH), patched (PTCH), smoothened and glioma-associated oncogene (GLI)1, 2 and 3, were continuously expressed and showed dynamic changes in proliferating SHPCs. In addition, the expression levels of IHH, PTCH and GLI1 were significantly different as compared with those of the control group at the same time point, and there were significant differences among the various time points in the experimental group (P<0.01). Furthermore, there was an association between the postoperative day and expression levels of HH components in the retrorsine-treated group. An immunohistochemical analysis demonstrated that PTCH was also expressed at the protein level. In conclusion, the results of the present study suggested that the HH was continuously activated during the proliferation of SHPCs, thus indicating that SHPCs may be a subgroup of stem cells that are regulated by the HH.

Fas signaling promotes chemoresistance in gastrointestinal cancer by up-regulating P-glycoprotein.

Fas signaling promotes metastasis of gastrointestinal (GI) cancer cells by inducing epithelial-mesenchymal transition (EMT), and EMT acquisition has been found to cause cancer chemoresistance. Here, we demonstrated that the response to chemotherapy of GI cancer patients with higher expression of FasL was significantly worse than patients with lower expression. Fas-induced activation of the ERK1/2-MAPK pathway decreased the sensitivity of GI cancer cells to chemotherapeutic agents and promoted the expression of P-glycoprotein (P-gp). FasL promoted chemoresistance of GI cancer cell via upregulation of P-gp by increasing ß-catenin and decreasing miR-145. ß-catenin promoted P-gp gene transcription by binding with P-gp promoter while miR-145 suppressed P-gp expression by interacting with the mRNA 3'UTR of P-gp. Immunostaining and qRT-PCR analysis of human GI cancer samples revealed a positive association among FasL, ß-catenin, and P-gp, but a negative correlation between miR-145 and FasL or P-gp. Altogether, our results showed Fas signaling could promote chemoresistance in GI cancer through modulation of P-gp expression by ß-catenin and miR-145. Our findings suggest that Fas signaling-based cancer therapies should be administered cautiously, as activation of this pathway may not only lead to apoptosis but also induce chemoresistance.

Porcine reproductive and respiratory syndrome virus induces IL-1ß production depending on TLR4/MyD88 pathway and NLRP3 inflammasome in primary porcine alveolar macrophages.

Porcine reproductive and respiratory syndrome virus (PRRSV) is an Arterivirus that has been devastating the swine industry worldwide since the late 1980s. Previous studies have reported that PRRSV infection induced the production of IL-1 ß . However, the cellular sensors and signaling pathways involved in this process have not been elucidated yet. Here, we studied the mechanisms responsible for the production of IL-1 ß in response to highly pathogenic PRRSV. Upon PRRSV infection of primary porcine alveolar macrophages, both mRNA expression and secretion of IL-1 ß were significantly increased in a time- and dose-dependent manner. We also investigated the role of several pattern-recognition receptors and adaptor molecules in this response and showed that the TLR4/MyD88 pathway and its downstream signaling molecules, NF- κ B, ERK1/2, and p38 MAPKs, were involved in IL-1 ß production during PRRSV infection. Treatment with specific inhibitors or siRNA knockdown assays demonstrated that components of the NLRP3 inflammasome were crucial for IL-1 ß secretion but not for IL-1 ß mRNA expression. Furthermore, TLR4/MyD88/NF- κ B signaling pathway was involved in PRRSV-induced expression of NLRP3 inflammasome components. Together, our results deciphered the pathways leading from recognition of PRRSV to the production and release of IL-1 ß , providing a deeper knowledge of the mechanisms of PRRSV-induced inflammation responses.

miR-23a inhibits E-cadherin expression and is regulated by AP-1 and NFAT4 complex during Fas-induced EMT in gastrointestinal cancer.

Fas signaling has been shown to induce the epithelial-mesenchymal transition (EMT) to promote gastrointestinal (GI) cancer metastasis, but the involvement of microRNA in this mechanism remains unknown. We found that Fas ligand (FasL) treatment inhibited E-cadherin expression and promoted cell invasion by upregulation of miR-23a, but overexpression of the miR-23a inhibitor could partially block this activity. FasL-induced extracellular signal-regulated kinase/mitogen-activated protein kinase signaling activated the activator protein 1 (AP-1) complex and repressed glycogen synthase kinase-3ß activity, which contributed to nuclear translocation of AP-1 and nuclear factor of activated T cells (NFAT4). Nuclear accumulation and interaction of AP-1 and NFAT4 and subsequent binding to the miR-23a promoter led to increased miR-23a expression. Inhibition of Fas signaling by downregulation of the Fas receptor led to a decrease in miR-23a expression and cell invasion ability in vivo and in vitro, as well as an increase in E-cadherin. Evaluation of human GI precancerous and cancer specimens showed that the expression of FasL and miR-23a increased, whereas the expression of E-cadherin decreased during GI cancer progression. A significant correlation was noted between any two of these three molecules. An EMT phenotype was shown to correlate with an advanced cancer stage and worse prognosis. Taken together, our results show that miR-23a participates in the mechanism of the FasL-induced EMT process and may serve as a potential therapeutic target for cancer metastasis.

Glycogen synthase kinase-3 beta regulates Snail and ß-catenin expression during Fas-induced epithelial-mesenchymal transition in gastrointestinal cancer.

Fas signalling has been shown to induce the epithelial-mesenchymal transition (EMT) to promote gastrointestinal (GI) cancer metastasis, but its mechanism of action is still unknown. The effects of Fas-ligand (FasL) treatment and inhibition of Fas signalling on GI cancer cells were tested using invasion assay, immunofluorescence, immunoblot, Reverse Transcription Polymerase Chain Reaction (RT-PCR), quantitative Real-time PCR (qRT-PCR), immunoprecipitation and luciferase reporter assay. Immunohistochemistry was used to analyse the EMT-associated molecules in GI cancer specimens. FasL treatment inhibited E-cadherin transcription by upregulation of Snail in GI cancer cells. The nuclear expression and transcriptional activity of Snail and ß-catenin were increased by inhibitory phosphorylation of glycogen synthase kinase-3 beta (GSK-3ß) at Ser9 by FasL-induced extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signalling. Snail associated with ß-catenin in the nucleus and, thus, increased ß-catenin transcriptional activity. Evaluation of human GI cancer specimens showed that the expression of FasL, phospho-GSK-3ß, Snail and ß-catenin increase during GI cancer progression. An EMT phenotype was shown to correlate with an advanced cancer stage, and a non-EMT phenotype significantly correlated with a better prognosis. Collectively, these data indicate that GSK-3ß regulates Snail and ß-catenin expression during Fas-induced EMT in gastrointestinal cancer.

Use of nitrocellulose membranes as a scaffold in cell culture.

Nitrocellulose membranes, one of the most important and oldest cellulose derivatives, are commonly used for nucleic acid and protein detection in research and diagnostic applications. However, a limited number of studies have explored whether they can act as scaffolds for cell growth. In this study, we investigated this polymeric material for its ability to support the growth of human cells. Eight established cell lines were examined for adherence, growth, spread, and survival on nitrocellulose membranes by optical microscopy after hematoxylin and eosin and/or immunocytochemical staining and by scanning electron microscopy. Apoptosis and leakage of lactate dehydrogenase (LDH) were also assessed. All cells readily adhered to and spread on the surface of nitrocellulose membranes as well as coverslips, and the cells maintained the expression of digestive system-specific genes. No significant change was detected in apoptosis or leakage of LDH from cells grown on nitrocellulose membranes. These results suggested that nitrocellulose membranes have a suitable cytocompatibility towards human cells and that they might be used for tissue-engineering scaffolds. Moreover, we demonstrate an additional and underused property of nitrocellulose of specific relevance to microscopic imaging, as it can be rendered virtually transparent, thus the cells growing on such membranes can be observed directly under an optical microscope after staining.

The role of hedgehog signaling pathway in liver regeneration.

BACKGROUND/AIMS: In this study, we explored the role of the Hedgehog signaling pathway in liver regeneration. METHODOLOGY: Retrorsine, partial hepatectomy and combined were utilized in mature Fisher344 rats. Specific assays, such as RT-PCR, real-time PCR and immunohistochemistry were used to detect the constituents of the Hedgehog signaling pathway during liver regeneration. RESULTS: mRNA expression of Ihh, Ptc, Smo, Gli1, Gli2 and Gli3 were all shown in liver tissue homogenates in control/normal, retrorsine, partial hepatectomy and retrorsine/partial hepatectomy groups while no Shh expression was found. Real-time PCR analysis indicated that there were significant differences in Hedgehog signaling pathway-related constituents (Ihh, Ptc, Gli1 and Gli3) among the different treatment groups and at distinct time points in the same treatment group during liver regeneration. The data also suggested an interaction effect between different treatment and time to the variation of Ihh, Ptc, Gli1 and Gli3. The protein expression of Ptc and Gli1 in liver regeneration was confirmed by immunohistochemistry, which differed in the duration among different groups. Nevertheless, the protein expression of Ptc and Gli1 were not detected successfully by western blot. CONCLUSIONS: It appears that the Hedgehog signaling pathway may be involved in liver regeneration.

[Purification of plasmid DNA using anion-exchange chromatography and removal of endotoxin].

The plasmid DNA was purified using the Fractogel EMD TMAE (M) anion exchange media. The dynamic loading capacity of this media for plasmid DNA was 0.62 mg/mL. It was found that when the lysate of bacteria was incubated with either Triton X-114 or Triton X-100 before purification, the average content of endotoxin left in the purified plasmid DNA was 6.42 EU/mg or 9.50 EU/mg, respectively. These results were much lower than that without pre-incubation (67.82 EU/mg). The purification of plasmid DNA and the removal of endotoxin were achieved in one step using anion-exchange chromatography. This method is simple, fast and of low cost.