3,973 research outputs found
Preparative Synthesis of dTDP-L-Rhamnose Through Combined Enzymatic Pathways
dTDP-L-rhamnose, an important precursor of O-antigen, was prepared on a large scale from dTMP by executing an one-pot reaction in which six enzymes are involved. Two enzymes, dTDP-4-keto-6-deoxy-D-glucose 3,5-epimerase and dTDP-4-keto-rhamnose reductase, responsible for the conversion of dTDP-4-keto-6-deoxy- D-glucose to dTDP-L-rhamnose, were isolated from their putative sequences in the genome of Mesorhizobium loti, functionally expressed in Escherichia coli, and their enzymatic activities were identified. The two enzymes were combined with an enzymatic process for dTDP-4- keto-6-deoxy-D-glucose involving TMP kinase, acetate kinase, dTDP-glucose synthase, and dTDP-glucose 4,6- dehydratase, which allowed us to achieve a preparative scale synthesis of dTDP-L-rhamnose using dTMP and glucose-1-phosphate as starting materials. About 82% yield of dTDP-L-rhamnose was obtained based on initial dTMP concentration at 20 mM dTMP, 1 mM ATP, 10 mM NADH, 60 mM acetyl phosphate, and 80 mM glucose-1- phosphate. From the reaction with 20 ml volume, approximately 180 mg of dTDP-L-rhamnose was obtained in an overall yield of 60% after two-step purification, that is, anion exchange chromatography and gel filtration for desalting. The purified product was identifiedbyHPLC, ESI-MS,andNMR,showingabout95%purity
Anti-Inflammatory Effects of Bangpungtongsung-San, a Traditional Herbal Prescription
Bangpungtongsung-san (BPTS), a traditional oriental herbal prescription, is widely used for expelling wind, draining heat, and providing general improvement to the immune system. In this study, we investigated the effects of BPTS on induction of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), proinflammatory cytokines, nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinases (MAPKs) in lipopolysaccharide- (LPS- ) stimulated Raw 264.7 cells, and on paw edema in rats. At concentrations of 0.5, 0.75, and 1 mg/mL, treatment with BPTS inhibited levels of expression of LPS-induced NF-κB and MAPKs (ERK, JNK, and p38) as well as production of proinflammatory mediators, such as nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) by LPS. These results suggest that BPTS may exert anti-inflammatory effects via reduction of proinflammatory mediators, including NO, PGE2, TNF-α, and IL-6 through suppression of the signaling pathways of NF-κB and MAPKs in LPS-induced macrophages. In addition, using the carrageenan-induced paw edema assay, an antiedema effect of BPTS was observed in rats. These findings may provide scientific evidence validating the use of BPTS in treatment of patients with heat syndrome in Korean oriental medicine
Malignancies in Korean Patients with Inflammatory Myopathy
The aim of this study was to assess the prevalence and the common type of malignancies in Korean patients with polymyositis (PM) and dermatomyositis (DM) and to evaluate the differences of clinical and laboratory findings between patients with malignancy and those without malignancy. Forty-one Korean patients, who were diagnosed as PM or DM, were enrolled in this study. They fulfilled the Bohan and Peter's criteria for a definite diagnosis of PM and DM. Patients with PM were 25 and those with DM were 16. Eleven out of 41 patients (26.8%) had malignancies. The malignancy was diagnosed simultaneously or later in 81.8% of patients with inflammatory myopathy (IM). The breast cancer was the most common malignancy. In this study, forty three years old as a screening age for malignancy had 88.9% sensitivity and 50.2% specificity. The serum levels of creatine kinase (CK) were significantly lower in patients with malignancy than those without malignancy
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Fabrication of Complex 3D Micro-Scale Scaffolds and Drug Delivery Devices using Dynamic Mask Projection Microstereolithography
Microstereolithography (μSL) technology can fabricate three-dimensional (3D) tissue
engineered scaffolds with controlled biochemical and mechanical micro-architectures. A
μSL system for tissue engineering was developed using a Digital Micromirror Device
(DMDTM) for dynamic pattern generation and an ultraviolet (UV) lamp filtered at 365 nm for
crosslinking the photoreactive polymer solution. The μSL system was designed with x-y
resolution of ~2 μm and a vertical (z) resolution of ~1 μm. To demonstrate the use of μSL in
tissue engineering, poly(propylene fumarate) (PPF) was synthesized with a molecular weight
of ~1200 Da. The viscosity of the PPF was reduced to ~150 cP (at 50 o
C) by mixing with
diethyl fumarate (DEF) in the ratio of 7:3 (w/w). Finally, ~2 % (w/w) of (bis(2,4,6-
trimethylbenzoyl) phenylphosphine oxide (BAPO) was added to the solution to serve as a
photoinitiator. Cure depth experiments were performed to determine the curing
characteristics of the synthesized PPF, and the resulting system and photopolymer were used
to construct a variety of 3D porous scaffolds with interconnected pores between 100 and 150
μm and a micro-needle array with height of ~800 μm and individual tip diameters of ~20 μm.
SEM and microscope images of the micro-architectures illustrate that the developed μSL
system is a promising technology for producing biodegradable and biocompatible
microstructures.Mechanical Engineerin
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