Improvement of retinoids production in recombinant E. coli using glyoxylic acid

Isoprenoids are the most chemically diverse compounds found in nature. They are present in all organisms and have essential roles in membrane structure, redox chemistry, reproductive cycles, growth regulation, signal transduction and defense mechanisms. In spite of their diversity of functions and structures, all isoprenoids are derived from the common building blocks of isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP). Optimization of IPP synthesis pathway is of benefit to mass production of various isoprenoids. There are two pathways of 2-C-Methyl-D-erythritol-4-phosphate (MEP) and mevalonate (MVA) for IPP synthesis. Prokaryotes including E. coli generally use MEP pathway whereas MVA pathway is used in eukaryotes. To improve isoprenoid production, it was performed the deletion of genes in E. coli, which are involved in both formation of fermentation by-products such as organic acids and alcohols, and consumption of precursors of MEP and MVA pathways, pyruvate and acetyl-CoA. As a result, we were able to develop a strain with improved fermentation productivity and carbon source utilization efficiency, the mutant strain was called AceCo. Higher lycopene production was achieved in the AceCo strain compared to the wild type MG1655 strain due to no formation of the inhibitory by-products. However, retinoids production of AceCo strain decreased to a half of that of MG1655 strain. Please click Additional Files below to see the full abstract

Sequential whole cell conversion process for production of D-psicose and D- mannitol from D-fructose

Rare sugars, which exist only limited quantities naturally, have received considerable attention because of its various specific nutritional and biological functions. Likewise, D-psicose (D-ribo-2-hexulose or D-allulose), a C-3 epimer of D-fructose, has many uses which include reducing intra-abdominal fat accumulation, protecting pancreas beta-islets and improving insulin sensitivity. Especially, D-psicose has only 0.3% calories compared to sucrose, while it has 70% relative sweetness. Additionally, in 2012, D-psicose was approved as a food additive and designated as Generally Recognized As Safe (GRAS) by Food and Drug Administration (FDA). Despite such abundant advantages, there is no economical way of mass production of D-psicose. Recently, biological production of D-psicose from D-fructose using D-psicose 3-epimerase (DPE) has been developed. However, the conversion yield is below 30%, which causes an undesirable increase of purification cost because of the similar solubility of D-psicose and D-fructose. Thus, we addressed the problem by converting the residual fructose, after the reaction of D-psicose production, to D-mannitol, which has a low solubility. The sequential whole cell conversion reactions for D-psicose and D-mannitol allow a convenient and economic purification of both products. This work was supported by a grant from the Next-Generation BioGreen 21 Program (SSAC, grant#: PJ01106201), RDA, Korea. Reference 1) Carsten Bäumchen & Stephanie Bringer-Meyer (2007), Expression of glf Z.m. increases D-mannitol formation in whole cell biotransformation with resting cells of Corynebacterium glutamicum, Appl Microbiol Biotechnol 76(3):545–52. 2) Ortiz, M. E., Bleckwedel, J., Raya, R. R., & Mozzi, F. (2013). Biotechnological and in situ food production of polyols by lactic acid bacteria, Appl Microbiol Biotechnol 97:4713-4726 3) Park, Y., Oh, E. J., Jo, J., Jin, Y., & Seo, J. (2016). Recent advances in biological production of sugar alcohols. Curr Opin Biotechnol 37:105–113

Optimization of extraction process for enhancement of antioxidant activity of Acer mono bark

Response surface methodology (RSM) was used for finding the optimum extraction condition of Acer mono bark. Twenty experimental conditions were set based on three key variables such as temperature, time and pressure by signalling reaction variables with 5 levels of - 2, - 1, 0, 1, 2 in accordance with central composite design for proceeding extraction and antioxidant tests. The optimized condition for the highest extraction yields was 13.10% at 83.48°C, 54.36 MPa for 13.08 minutes. For DPPH radical scavenging ability, an optimal condition was 92.89% at 88.50°C, 49.69 MPa for 15.08 minutes, and for SOD-like activity 40.69% at 85.21°C, 53.28 MPa for 15.83 minutes. The optimized condition for total polyphenol content was 4.23 mg/g at 81.51°C, 52.92 MPa for 14.79 minutes. The most optimized extraction condition was determined to be at 85°C, 52 MPa for 14 minutes for considering both extraction yield and its biological activities of this plant

Antioxidant effect of lidocaine and procaine on reactive oxygen species-induced endothelial dysfunction in the rabbit abdominal aorta

Background: Reactive oxygen species (ROS) induce lipid peroxidation and tissue damage in the endothelium. We tested the antioxidant effect of lidocaine and procaine on ROS-induced endothelial damage in the rabbit aorta. Methods: Aortic rings isolated from rabbits were suspended in an organ bath filled with Krebs-Henseleit (K-H) solution bubbled with 5% CO2 and 95% O 2 at 37.5??C. After precontraction with phenylephrine (PE, 10 -6 M), changes in tension were recorded following a cumulative administration of acetylcholine (ACh 3 ?? 10-8 to 10 -6 M). Differences were measured as percentages of ACh-induced relaxation of aortic rings before and after exposure to ROS as generated by electrolysis of the K-H solution. The aortic rings were pretreated with lidocaine or procaine (10-5 M to 3 ?? 10-3 M) to compare their effects, as well as ROS scavengers, catalase, mannitol, sodium salicylate, and deferoxamine, and a catalase inhibitor, 3-amino-1,2,4-triazole (3AT). Results: Lidocaine and procaine dose-dependently maintained endothelium-dependent relaxation induced by ACh despite ROS activity (P < 0.05 vs control value). The 3AT pretreated procaine (3 ?? 10-3 M) group decreased more significantly than the un-pretreated procaine group (P < 0.05). Conclusions: These findings suggest that lidocaine and procaine dose-dependently preserve endothelium-dependent vasorelaxation against ROS attack, potentially via hydrogen peroxide scavenging. Copyright ?? Korean Society of Anesthesiologists, 2010

Helical tomotherapy with concurrent capecitabine for the treatment of inoperable pancreatic cancer

<p>Abstract</p> <p>Background</p> <p>Helical tomotherapy, an advanced intensity-modulated radiation therapy with integrated CT imaging, permits highly conformal irradiation with sparing of normal tissue. Capecitabine, a pro-drug of 5-FU that induces thymidine phosphorylase can achieve higher levels of intracellular 5-FU when administered concurrently with radiation. We evaluated the feasibility as well as the clinical outcome of concurrent administration of capecitabine with tomotherapy in patients with advanced pancreatic cancer.</p> <p>Methods</p> <p>Nineteen patients with advanced pancreatic cancer including primarily unresectable disease and recurrence after curative surgery were included in the study. Two planning target volumes (PTV) were entered: PTV1 is gross tumor volume; and PTV2, the volume of the draining lymph nodes. The total doses to target 1 and target 2 were 55 and 50 Gy, respectively. Capecitabine at 1600 mg/m²/day was administered on each day of irradiation.</p> <p>Results</p> <p>Twenty six measurable lesions were evaluated. Overall in-field response rate was 42.3%; partial responses were achieved in 53.3% of the pancreatic masses, 28.6% of distant metastatic lesions and 25.0% of regional lymph nodes. The median duration of follow-up after tomotherapy was 6.5 months. None of the lesions showed in-field progression. Treatment was well tolerated with only minor toxicities such as grade 1 nausea (one patient), grade 1 hand-foot syndrome (one patient) and grade 1/2 fatigue (three patients).</p> <p>Conclusions</p> <p>Helical tomotherapy with concurrent capecitabine is a feasible option without significant toxicities in patients with advanced pancreatic cancer. We achieved excellent conformal distribution of radiation doses and minimal treatment-related toxicities with promising target volume responses.</p

Efficacy of Scrambler Therapy in Patients With Painful Diabetic Peripheral Neuropathy: a Single-arm, Prospective, Pilot Study

BACKGROUND: A variety of medications are available to manage painful diabetic peripheral neuropathy (DPN), but the proper treatment remains challenging. Accordingly, various neuromodulation modalities have been used. However, no prospective clinical trials have evaluated the use of scrambler therapy (ST) in painful DPN. This study aimed to explore the long-term effects of ST in managing painful DPN. METHODS: The patients received 10 consecutive STs of 45 minutes every 1 to 2 days. The primary outcome was pain score. We measured the visual analog scale (VAS) pain scores at baseline, during ST, immediately after ST, and at 1, 2, 3, and 6 months after ST. The secondary outcomes were Michigan Neuropathy Screening Instrument (MNSI), Semmes-Weinstein monofilament test, and Leeds Assessment of Neuropathic Symptoms and Signs pain scores, which were measured at baseline, immediately after ST, and at 1, 2, 3, and 6 months after ST. RESULTS: VAS scores showed significant improvement at the 8th, 9th, and 10th sessions during ST and 1 month after ST. The MNSI self-report component score was decreased 1 month after the ST. However, all other outcomes did not show significant differences compared to the baseline. CONCLUSION: ST may have short-term effects and limited long-term effects on painful DPN

High performance polymer light-emitting diodes with N-type metal oxide/conjugated polyelectrolyte hybrid charge transport layers

We present an interfacial engineering strategy employing n-type-metal-oxide/conjugated-polyelectrolyte (CPE) hybrid charge-transport layers for highly efficient polymer light-emitting diodes (PLEDs). The hybrid metal-oxide/CPE layer facilitates electron-injection, while blocking hole-transport, and thereby maximizes electron-hole recombination within the emitting layer. A series of metal-oxide/CPE combinations were tested in inverted PLEDs (FTO/metal-oxide/CPF8BT/MoO3/Au). Specifically, HfO2/CPE double layer achieved an electroluminescence (EL) efficiency of up to 25.8 cd/A (@ 6.4 V, one of the highest values reported for fluorescent PLEDs).open11