Efficacy of induction chemotherapy in lymph node-positive stage III nasopharyngeal carcinoma and identification of beneficiaries based on clinical features: A propensity score matching analysis.

PURPOSE: To investigate the role of induction chemotherapy (IC) in lymph node-positive (LN-positive) stage III nasopharyngeal carcinoma (NPC) receiving concurrent chemoradiotherapy (CCRT). METHODS: In total, 627 patients with newly diagnosed LN-positive stage III NPC receiving CCRT or IC plus CCRT were included. The primary endpoint was progression-free survival (PFS). Propensity-score matching (PSM) was conducted to balance the intergroup covariates. Kaplan-Meier method with log-rank test was employed to compare survival curves. Subgroup analyses were conducted based on baseline characteristics. RESULTS: After 1:1 PSM, 414 patients were identified (207 patients per group). Compared with CCRT, IC plus CCRT provided better survival (5-year PFS 88.4% vs. 78.6%, P = 0.01; overall survival [OS] 94.8% vs. 85.3%, P = 0.003; and distant metastasis-free survival [DMFS] 93.1% vs. 85.6%, P = 0.03). The IC beneficial effects on PFS were mainly present in patients with grade 2-3 ENE, elevated serum lactate dehydrogenase (LDH > 170U/L), and N2 disease. Patients with grade 2 CNN had comparable PFS benefits to those with grade 0-1 CNN. For patients with grade 0-1 ENE combined with LDH ≤ 170U/L, survival between the two groups was similar with 5-year PFS 93.6% vs. 90.4% (P = 0.50), OS 94.2% vs. 93.0% (P = 0.72), and DMFS 98.6% vs. 97.7% (P = 0.98). CONCLUSION: Adding IC before CCRT improved survival in LN-positive stage III NPC patients. Additional IC did not provide better survival for patients with grade 0-1 ENE combined with LDH ≤ 170U/L and could be avoided in this population. CNN may not be a good risk factor for tailoring a personalized treatment plan.

Influence of oxygen on the biosynthesis of polyunsaturated fatty acids in microalgae.

As one of the most important environmental factors, oxygen is particularly important for synthesis of n-3 polyunsaturated fatty acids (n-3 PUFA) in microalgae. In general, a higher oxygen supply is beneficial for cell growth but obstructs PUFA synthesis. The generation of reactive oxygen species (ROS) under aerobic conditions, which leads to the peroxidation of lipids and especially PUFA, is an inevitable aspect of life, but is often ignored in fermentation processes. Irritability, microalgal cells are able to activate a number of anti-oxidative defenses, and the lipid profile of many species is reported to be altered under oxidative stress. In this review, the effects of oxygen on the PUFA synthesis, sources of oxidative damage, and anti-oxidative defense systems of microalgae were summarized and discussed. Moreover, this review summarizes the published reports on microalgal biotechnology involving direct/indirect oxygen regulation and new bioreactor designs that enable the improved production of PUFA.

[Wavelength Variable Selection Method in Near Infrared Spectroscopy Based on Discrete Firefly Algorithm].

Taking into consideration of the large size of near-infrared spectral data, the spectral data has to be compressed to reduce the computational complexity of the established spectral calibration model and improve accuracy and robustness of the model. Near Infrared Spectroscopy wavelength variable selection method based on discrete firefly algorithm is presented. First, the Monte Carlo method was used to exclude outliers, and Kennard-Stone method was chosen for the selection of calibration set and prediction set. General firefly algorithm was discretized, by improving the attractiveness of adaptive formula, increasing traction weights in mobile formula and so on. In order to adapt to the effects of discretization and optimize algorithm, elitist strategy was added in the discrete firefly algorithm, to accelerate the convergence rate. The optimum value of the DFA algorithm parameters was found in the experiment. With wavelength variables selection based on discrete firefly algorithm, succinic acid concentration of the fermentation broth partial least squares NIR calibration model was built, which was compared with genetic algorithm method. The results showed that the correlation coefficient of calibration set (R2c) of PLS calibration model based on discrete wavelengths firefly algorithm is 0.986, RMSEC of which is 0.409. Correlation coefficient of prediction set (R2p) is 0.969 while RMSEP is 0.458. It is superior to full spectrum modeling and calibration model using genetic algorithm method. DFA shows superiority of the near-infrared spectral data filtering.

Selective Radiotherapy after Distant Metastasis of Nasopharyngeal Carcinoma Treated with Dose-Dense Cisplatin plus Fluorouracil.

PURPOSE: To investigate the efficacy and safety of selective radiotherapy after distant metastasis of nasopharyngeal carcinoma (NPC) treated with dose-dense cisplatin plus fluorouracil. MATERIALS AND METHODS: Eligible patients were randomly assigned to a study group treated with dose-dense cisplatin plus fluorouracil following selective radiotherapy and a control group receiving traditional cisplatin plus fluorouracil following selective radiotherapy according to a 1:1 distribution using a digital random table method. The primary endpoint was overall survival (OS). Secondary endpoints were progression-free survival (PFS), objective response rate, relapse or progression rate in the radiation field and treatment toxicity. RESULTS: Of 52 patients in the study group, 20 cases underwent radiotherapy., while in the control group of 51 patients, 16 underwent radiotherapy. The median PFS, median OS, survival rates in 1, 2 and 3 years in study and control group were 20.9 vs 12.7months, 28.3 vs 18.8months, 85.2%vs 65.9%, 62.2% vs 18.3%, and 36.6%vs 5.2% (p values of 0.00, 0.00, 0.04, 0.00 and 0.00, respectively). Subgroup analysis showed that the median OS and survival rates of 1, 2, 3 years for patients undergoing radiotherapy in the study group better than that in control group( 43.2vs24.1 months, 94.1% vs 86.7%, 82.4% vs 43.3%, 64.7% vs 17.3%, (p=0.00, 0.57, 0.04 and 0.01, respectively). The complete response rate, objective response rate after chemotherapy and three months after radiotherapy, relapse or progression rate in radiation field in study group and in control group were 19.2% vs 3.9%, 86.5% vs 56.9%, 85% vs 50%, 95% vs 81.3% and 41.3% vs 66.7% (p =0.03, 0.00, 0.03,0.30, 0.01 respectively). The grade 3-4 acute adverse reactions in the study group were significantly higher than in the control group (53.8% vs 9.8%, p=0.00). CONCLUSIONS: The survival of patients benefits from selective radiotherapy after distant metastasis of NPC treated with dose-dense cisplatin plus fluorouracil.

Ultrasonic pretreatment and acid hydrolysis of sugarcane bagasse for succinic acid production using Actinobacillus succinogenes.

Immense interest has been devoted to the production of bulk chemicals from lignocellulose biomass. Diluted sulfuric acid treatment is currently one of the main pretreatment methods. However, the low total sugar concentration obtained via such pretreatment limits industrial fermentation systems that use lignocellulosic hydrolysate. Sugarcane bagasse hemicellulose hydrolysate is used as the carbon and nitrogen sources to achieve a green and economical production of succinic acid in this study. Sugarcane bagasse was ultrasonically pretreated for 40 min, with 43.9 g/L total sugar obtained after dilute acid hydrolysis. The total sugar concentration increased by 29.5 %. In a 3-L fermentor, using 30 g/L non-detoxified total sugar as the carbon source, succinic acid production increased to 23.7 g/L with a succinic acid yield of 79.0 % and a productivity of 0.99 g/L/h, and 60 % yeast extract in the medium could be reduced. Compared with the detoxified sugar preparation method, succinic acid production and yield were improved by 20.9 and 20.2 %, respectively.

Succinic acid production by Actinobacillus succinogenes NJ113 using corn steep liquor powder as nitrogen source.

In this study, corn steep liquor powder (CSL) was used as nitrogen source to replace the relatively costly yeast extract typically used for the production of succinic acid with Actinobacillus succinogenes NJ113. Moreover, when heme was added to the fermentation medium and the culture was agitated at a low speed, a maximum succinic acid concentration of 37.9 g/l was obtained from a glucose concentration of 50 g/l, and a productivity of 0.75 g/l/h was achieved. These yields are almost as high as for fermentation with glucose and yeast extract. These results suggest that heme-supplemented CSL may be a suitable alternative nitrogen source for a cost-effective method of producing succinic acid with A. succinogenes NJ113 while consuming less energy than previous methods.

Succinic acid production from cellobiose by Actinobacillus succinogenes.

In this study, cellobiose, a reducing disaccharide was used to produce succinic acid by Actinobacillus succinogenes NJ113. A final succinic acid concentration of 30.3g/l with a yield of 67.8% was achieved from an initial cellobiose concentration of 50 g/l via batch fermentation in anaerobic bottles. The cellobiose uptake mechanism was investigated and the results of enzyme assays revealed that the phosphoenolpyruvate phosphotransferase system (PEP-PTS) played an important role in the cellobiose uptake process. In batch fermentation with 18 g/l of cellobiose and 17 g/l of other sugars from sugarcane bagasse cellulose hydrolysates, a succinic acid concentration of 20.0 g/l was obtained, with a corresponding yield of 64.7%. This study found that cellobiose from incomplete hydrolysis of cellulose could be a potential carbon source for economical and efficient succinic acid production by A. succinogenes.

Anti-fibrotic effects via regulation of transcription factor Sp1 on hepatic stellate cells.

BACKGROUND: Hepatic stellate cells (HSCs), the central cells in hepatic fibrosis, are characterized by sustaining activation, a process that consists in increased proliferation and over-expression of fibrotic genes. Transcription factor Sp1 mediates the expression of a variety of fibrotic genes expression and thereby play an important role in fibrosis. In addition, previous reports have indicated that Sp1 binding activity is greatly increased in activated HSCs. Thus, our aim was to investigate the anti-proliferative and anti-fibrotic effects of the oligonuceotide decoy of the transcription factor Sp1, ODN, a potent inhibitor of Sp1-activated transcription. METHODS: We optimized Lipofectamin 2000 (LF2000):ODN DNA ratio for the transfection of hepatic stellate cells HSC-T6. Then we measure the effect of transfected ODN on HSC-T6 cells' proliferation and fibrotic gene expression, and study the mechanism involved. RESULTS: At a DNA concentration of 1 µM and a ratio ODN DNA:LF2000 of 1:3, HSC-T6 cells have the maximal transfection efficiency with the lowest toxicity. Transfected ODN effectively blocks Sp1 binding to the promoter regions of cell cycle regulatory proteins cyclin D1, p27(KIP1) and fibrotic genes, including transforming growth factor (TGF)-ß1, Platelet-derived growth factor (PDGF)-BB, α-SMA, α1 (I) collagen and tissue inhibitor of metalloproteinases-1 (TIMP-1). ODN inhibits HSC-T6 proliferation and fibrotic genes expression in vitro. CONCLUSION: Sp1 is a key transcription factor that mediates proliferation and fibrotic gene synthesis of HSC-T6, inhibition of Sp1 with decoy ODN may be an effective approach to prevent the progression of hepatic fibrosis.

Increased production of succinic acid in Escherichia coli by overexpression of malate dehydrogenase.

Escherichia coli NZN111 is a double mutant with inactivated lactate dehydrogenase and pyruvate formate-lyase. It cannot utilize glucose anaerobically because of its unusually high intracellular NADH/NAD(+) ratio. We have now constructed a recombinant strain, E. coli NZN111/pTrc99a-mdh, which, during anaerobic fermentation, produced 4.3 g succinic acid l(-1) from 13.5 g glucose l(-1). The NADH/NAD(+) ratio decreased from 0.64 to 0.26. Furthermore, dual-phase fermentation (aerobic growth followed by anaerobic phase) resulted in enhanced succinic acid production and reduced byproduct formation. The yield of succinic acid from glucose during the anaerobic phase was 0.72 g g(-1), and the productivity was 1.01 g l(-1) h(-1).

A complete industrial system for economical succinic acid production by Actinobacillus succinogenes.

An industrial fermentation system using lignocellulosic hydrolysate, waste yeast hydrolysate, and mixed alkali to achieve high-yield, economical succinic acid production by Actinobacillus succinogenes was developed. Lignocellulosic hydrolysate and waste yeast hydrolysate were used efficiently as carbon sources and nitrogen source instead of the expensive glucose and yeast extract. Moreover, as a novel method for regulating pH mixed alkalis (Mg(OH)(2) and NaOH) were first used to replace the expensive MgCO(3) for succinic acid production. Using the three aforementioned substitutions, the total fermentation cost decreased by 55.9%, and 56.4 g/L succinic acid with yield of 0.73 g/g was obtained, which are almost the same production level as fermentation with glucose, yeast extract and MgCO(3). Therefore, the cheap carbon and nitrogen sources, as well as the mixed alkaline neutralize could be efficiently used instead of expensive composition for industrial succinic acid production.

Optimization of culture conditions in CO2 fixation for succinic acid production using Actinobacillus succinogenes.

The culture conditions in CO(2) fixation by Actinobacillus succinogenes for succinic acid production were investigated by a model of available CO(2) in a 3-l fermentor. The results from the model analysis showed that the available CO(2) for succinic acid production in the fermentation broth is the sum of HCO(3) (-), CO(3) (2-), and CO(2) influenced by external culture conditions such as medium components, CO(2) partial pressures, and temperature. The optimized conditions for CO(2) supply in a 3-l fermentor were determined as follows: CO(2) partial pressure and stirring speed were maintained at 0.1 MPa and 200 r min(-1), respectively, with a pH of 6.8 and a temperature of 37°C; 0.15 mol l(-1) NaHCO(3) was added. Under the optimized conditions, a CO(2) fixation rate of 0.57 g l(-1) h(-1) was obtained, and a succinic acid concentration of 51.6 g l(-1) with a yield of 75.8% was reached. These results suggest that optimized conditions of CO(2) supply are effective in high succinic acid production and thus have potential applications in succinic acid production and CO(2) fixation.

Succinic acid production by Actinobacillus succinogenes using hydrolysates of spent yeast cells and corn fiber.

The enzymatic hydrolysate of spent yeast cells was evaluated as a nitrogen source for succinic acid production by Actinobacillus succinogenes NJ113, using corn fiber hydrolysate as a carbon source. When spent yeast cell hydrolysate was used directly as a nitrogen source, a maximum succinic acid concentration of 35.5 g/l was obtained from a glucose concentration of 50 g/l, with a glucose utilization of 95.2%. Supplementation with individual vitamins showed that biotin was the most likely factor to be limiting for succinic acid production with spent yeast cell hydrolysate. After supplementing spent yeast cell hydrolysate and 90 g/l of glucose with 150 µg/l of biotin, cell growth increased 32.5%, glucose utilization increased 37.6%, and succinic acid concentration was enhanced 49.0%. As a result, when biotin-supplemented spent yeast cell hydrolysate was used with corn fiber hydrolysate, a succinic acid yield of 67.7% was obtained from 70.3 g/l of total sugar concentration, with a productivity of 0.63 g/(l h). Our results suggest that biotin-supplemented spent yeast cell hydrolysate may be an alternative nitrogen source for the efficient production of succinic acid by A. succinogenes NJ113, using renewable resources.

Strategies for efficient repetitive production of succinate using metabolically engineered Escherichia coli.

Escherichia coli AFP111, a pflB, ldhA, ptsG triple mutant of E. coli W1485, can be recovered for additional succinate production in fresh medium after two-stage fermentation (an aerobic growth stage followed by an anaerobic production stage). However, the specific productivity is lower than that of two-stage fermentation. In this study, three strategies were compared for reusing the cells. It was found when cells were aerobically cultivated at the end of two-stage fermentation without supplementing any carbon source, metabolites (mainly succinate and acetate) could be consumed. As a result, enzyme activities involved in the reductive arm of tricarboxylic acid cycle and the glyoxylate shunt were enhanced, yielding a succinate specific productivity above g⁻¹(DCW)h⁻¹ and a mass yield above 0.90 g g⁻¹ in the subsequent anaerobic fermentation. In addition, the intracellular NADH of cells subjected to aerobic cultivation with metabolites increased by more than 3.6 times and the ratio of NADH to NAD+ increased from 0.4 to 1.3, which were both favorable for driving the TCA branch to succinate.

Isolation of NH4+-tolerant mutants of Actinobacillus succinogenes for succinic acid production by continuous selection.

Actinobacillus succinogenes, a typical succinic acid producing microorganism, was inhibited seriously by ammonium ion, which hampered industrialization of A. succinogenes with ammonium ion based material as the pH controller. In this study, we have isolated an ammonium ion-tolerant mutant of A. succinogenes by continuous-culture technique in which all environmental factors beside the stress (ammonium ion) were maintained constant. In this technique, the mutant-generating system was not operated as a nutrient-limited chemostat, but as a nutrient-unlimited system where cells were continuous cultured at the maximum specific growth rate. Mutants were isolated on agar plates containing a acid-base indicator bromothymol blue and high level of ammonium ion which gives 100% killing of the parent strain. When cultured in anaerobic bottles at ammonium ion concentration of 354 mmol/L, the mutant YZ0819 could produce succinic acid 40.21 g/L with yield 80.4%, while the parent strain NJ113 did not grow. With NH4OH being used to buffer the culture pH in 3.0 liter stirred bioreactor, YZ0819 produced 35.15 g/L succinic acid with yield 70.3%, 155% higher than that obtained by NJ113. In addition, the morphology of YZ0819 in fermentation broths was changed. Cells of YZ0819 were aggregated from the beginning to the end of fermentation. These results indicate that YZ0819 would be used to be the potential strain produced efficiently succinic acid with NH4OH as the pH controller and the formation of aggregates may be useful as an aid in the transferring of cells from a cultivation medium for various industrial applications.

Succinic acid production with metabolically engineered E. coli recovered from two-stage fermentation.

Escherichia coli AFP111 cells recovered from spent two-stage fermentation broth were investigated for additional production of succinic acid under anaerobic conditions. Recovered cells produced succinic acid in an aqueous environment with no nutrient supplementation except for glucose and MgCO(3). In addition, initial glucose concentration and cell density had a significant influence on succinic acid mass yield and productivity. Although the final concentration of succinic acid from recovered cells was lower than from two-stage fermentation, an average succinic acid mass yield of 0.85 g/g was achieved with an average productivity of 1.81 g/l h after three rounds of recycling, which was comparable to two-stage fermentation. These results suggested that recovered cells might be reused for the efficient production of succinic acid.

Effect of redox potential regulation on succinic acid production by Actinobacillus succinogenes.

The effects of redox potential used as a control parameter on the process of succinic acid production in batch cultures of Actinobacillus succinogenes NJ113 have been investigated. In batch fermentation, cell growth and metabolite distribution were changed with redox potential levels in the range of -100 to -450 mV. From the results, the ORP level of -350 mV was preferable, which resulted in high succinic acid yield (1.28 mol mol(-1)), high succinic acid productivity (1.18 g L(-1) h(-1)) and high mole ratio of succinic acid to acetic acid (2.02). The mechanism of redox potential regulation was discussed by metabolic flux analysis and the ratio of NADH/NAD+. We expected that redox potential can be used as a valuable parameter to monitor and control much more anaerobic fermentation production.

Effect of growth phase feeding strategies on succinate production by metabolically engineered Escherichia coli.

Aerobic growth conditions significantly influenced anaerobic succinate production in two-stage fermentation by Escherichia coli AFP111 with knockouts in rpoS, pflAB, ldhA, and ptsG genes. At a low cell growth rate limited by glucose, enzymes involved in the reductive arm of the tricarboxylic acid cycle and the glyoxylate shunt showed elevated activities, providing AFP111 with intracellular redox balance and increased succinic acid yield and productivity.

[Effects of nuclear factor-kappa B p65 ASODN on transforming growth beta-1 and intercellular adhesion molecule-1 of rat hepatic stellate cells].

OBJECTIVE: To study the effects of nuclear factor (NF)-kappa B p65 ASODN on transforming growth factor beta-1 (TGF beta 1) and intercellular adhesion molecule-1 (ICAM-1) of rat hepatic stellate cells (HSC) and the mechanisms of NF-kappa B p65 ASODN in treating liver fibrosis. METHODS: Type IV collagen enzyme digestion and density centrifugation methods were used to separate rat hepatic stellate cells. NF-kappa B p65 ASODN was manually synthesized and completely phosphorothioate-modified. The changes of TGF beta 1 and ICAM-1 mRNA were detected by RT-PCR and albumen of TGF beta 1 and ICAM-1 were detected by ELISA. The changes of NF-kappa B activity were determined by ELISA. RESULTS: NF-kappa B activity and the expressions of ICAM-1 and TGF beta 1 increased after the HSC were treated by TNF alpha. NF-kappa B activity weakened after being treated with NF-kappa B p65 ASODN (0.001-1.000 micromol/L), P less than 0.05 in a dose dependent manner. Transferring NF-kappa B p65 ASODN (0.001-1.000 micromol/L) also weakened the expression of ICAM-1 and TGF beta 1 mRNA and the protein induced by TNF alpha in HSC. It was also in a dose dependent manner, P less than 0.05. CONCLUSIONS: After transferring NF-kappa B p65 ASODN into HSC, their NF-kappa B activity decreased, and their mRNA and protein expressions of ICAM-1 and TGF beta 1 also decreased. This may serve as a new way in treating hepatic fibrosis.