Effects of Continuous Epidural Injection of Dexamethasone on Blood Glucose, Blood Lipids, Plasma Cortisol and ACTH in Patients With Neuropathic Pain.

Objective: To study the effects of continuous epidural injection of dexamethasone on blood glucose, blood lipids, plasma cortisol, and adrenocorticotropic hormone (ACTH) in patients with neuropathic pain. Methods: Thirty patients with cervical spondylotic radiculopathy, lumbar disc herniation, herpes pain or postherpetic neuralgia were randomly divided into three groups and were treated with different doses of epidural injection of dexamethasone (Group S with a concentration of 25 µg/mL; Group M with a concentration of 50 µg/mL; Group L with a concentration of 100 µg/mL). Epidural catheterization placement was guided by computed tomography (CT), and was connected to the analgesic pump for 10 days. Visual Analog Score (VAS), fasting blood glucose (FBG), total cholesterol (CHOL), triglyceride (TG), 2 h postprandial blood glucose (2hPG) and the concentrations of cortisol, ACTH were measured before injection (T0), 2, 4, 6, 8, and 10 days during injection (D2, D4, D6, D8, D10), and 7, 14, 21, 28 days (W1, W2, W3, W4) after injection. Results: During and after the treatment, VAS score was significantly decreased, and group M and L had the lowest VAS score. The concentrations of cortisol and ACTH were significantly lower during the treatment, but all of them recovered to the normal level after stopping the injection. The treatment did not affect the CHOL and TG concentrations. Discussion: Epidural injection of dexamethasone at the concentration of 50 µg/mL is recommended for patients with neuropathic pain because of its good analgesic effect and less adverse effect on blood glucose, plasma cortisol, and ACTH.

N-[4-(4,6-Dimethyl-2-pyrimidinyloxy)-3-methylphenyl]-N'-[2-(dimethylamino)] benzoylurea induces cell-cycle arrest and apoptosis in human cancer cells.

N-[4-(4,6-Dimethyl-2-pyrimidinyloxy)-3-methylphenyl]-N'-[2-(dimethylamino)]benzoylurea (SUD) is a novel synthesized benzoylurea derivative. We selected several human cancer cell lines to investigate whether SUD can inhibit the growth of cancer cells. We selected the liver cell line L-02 to investigate the effect of SUD on the normal cells. Flow cytometric analysis was used to detect the effect of SUD on cell cycle, Hoechst 33258 staining was used to evaluate the apoptosis induced by SUD, real-time fluorescence quantitative PCR was used to investigate the expression of the cell cycle-relevant and apoptosis-relevant genes, a reactive oxygen species (ROS) assay was used to observe the production of ROS, and western blotting was used to determine the level of cell cycle-relevant and apoptosis-relevant proteins. According to the results of the MTT assay, the growth of human cancer cell lines was significantly inhibited by SUD treatment in a time-dependent and concentration-dependent manner; however, the growth of human normal cells was not significantly inhibited by SUD treatment. The results of flow cytometric analyses showed that SUD induced cell-cycle arrest at the G2-phase in MCF-7 cells and at the G1-phase in BGC-823 cells. The results of Hoechst 33258 staining showed that SUD induced apoptosis in MCF-7 and BGC-823 cells. The results of the ROS assay showed that the production of ROS was increased by SUD in MCF-7 and BGC-823 cells. Our research suggests that the growth-inhibitory effect of SUD on MCF-7 cells was related to G2-phase arrest, which was associated with the upregulated expression of p53 and Chk1 proteins, and downregulation of the cyclin B1 gene, cdc25a, and cyclin-dependent kinase 1 (CDK1) proteins; the growth-inhibitory effect of SUD on BGC-823 cells was related to G1-phase arrest, which was associated with upregulation of the p53 gene and Chk1 protein and downregulation of cdc25a protein and the CDK4 gene. SUD also induced apoptosis in MCF-7 and BGC-823 cell lines through the mitochondrial pathway in a p53-dependent manner.

Mechanism of monolignol biotransformation by Rhus laccases in water-miscible organic solutions.

Several important monolignols such as coniferyl alcohol were catalyzed using Rhus laccase (RL) from Rhus vernicifera in a water/acetone solution. The enzymatic mechanism is discussed in detail. Sites 6, ß, and phenolic oxygen were the main active sites of phenylpropanoid compounds, which were first oxidized by the enzyme and then radicalized. RL was also responsible for lignin biosynthesis, especially in the early stage.

Effects of organic solvents on the activity of free and immobilised laccase from Rhus vernicifera.

Rhus laccase (RL) was covalently immobilised onto chitosan, and the effects of immobilisation on pH optimum, enzyme activity, thermostability, and re-use evaluated, using either N,N-dimethyl-p-phenylenediamine or 2,6-dimethoxyphenol as substrate. Immobilisation greatly enhanced enzyme thermostability, resulted in negligible loss of activity, and showed excellent re-use potential, with >80% relative activity retained after 15 cycles in aqueous solvent. Immobilised Rhus laccase (I-RL) was more catalytically active in both hydrophobic and hydrophilic organic solvents than free RL. With water-immiscible organic solvents, both free RL and I-RL required a minimum water content to achieve activity. With water-miscible organic solvents, in general a water content of ∼20-50% (v/v) was required to achieve activity using free RL, whereas with I-RL less water was generally required to achieve enzyme activity, and therefore considerably higher relative activity was exhibited at lower water contents. Kinetic investigations showed that the rate of substrate disappearance generally followed a pseudo-first-order law, and for evaluated water-immiscible organic solvents rate constants generally increased with decrease of hydrophobicity, however, in water-miscible organic solvents no such relationship was observed. Some discussion of the potential interactions between organic solvent molecules and enzyme active centres was provided to explain obtained results.

N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride nanoparticle as a novel delivery system for parathyroid hormone-related protein 1-34.

Chitosan (CS) and epoxy propyl trimethyl ammonium chloride (EPTAC) were used to prepare the water-soluble N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC). HTCC and sodium tripolyphosphate (TPP) were mixed to form HTCC nanoparticles based on ionic gelation. Parathyroid hormone-related protein 1-34 (PTHrP1-34) was incorporated into the HTCC nanoparticles. The particle size and morphology of nanoparticles were determined by transmission electron microscopy (TEM). HTCC/PTHrP1-34 nanoparticles were 100-180 nm in size and their encapsulation efficiency and loading capacity were related to HTCC concentration, TPP concentration and initial concentration of PTHrP1-34. Relatively optimum encapsulation efficiency (78.4%) and loading capacity (13.7%) of PTHrP1-34 is achieved, and the in vitro release profile of PTHrP1-34 from nanoparticles has an initial burst, which is followed up by a slow release phase. These studies showed that HTCC/PTHrP1-34 nanoparticles are suitable for the treatment of osteoporosis, because of their slow-continuous-release properties, and the relevant in vivo experiments and clinical trials should be further studied.

Effects of lacquer polysaccharides, glycoproteins and isoenzymes on the activity of free and immobilised laccase from Rhus vernicifera.

The purified polysaccharides, glycoproteins, and isoenzymes of Rhus laccase, and crude enzymes, from Chinese lacquer (Rhus vernicifera sap) were used to determine their influence on the enzymic activity of Rhus laccase on several substrates (4-phenylenediamine, isoeugenol and coniferyl alcohol). No product identity changes were observed when these components were added singularly or in combination to the enzymic reactions (only relative product yields varied significantly), however, the polysaccharides (GP1 and GP2) and glycoprotein (stellacyanin, St) exhibited negative effects, and the two isoenzymes (L1 and L2) exhibited positive synergistic effects, on the activity of Rhus laccase. With respect to the activity of the crude enzymes, the negative effects of GP1, GP2 and St were greater than the positive effects of L1 and L2, compared with free Rhus laccase on its own (using 4-phenylenediamine as substrate), the estimated inhibitory effect (of GP1, GP2 and St) being by at least a factor of 50 (even with the positive effect of L1 and L2). This contributes to understanding of lacquer storage stability and drying rates. Immobilisation of crude enzymes using a variety of techniques (using natural and modified polysaccharides, and an inorganic support) where evaluated using isoeugenol as substrate. Agar embedding and zirconium chloride chelation methods resulted in the highest substrate conversion levels. The yields and products of isoeugenol catalysis using Vietnamese crude enzymes/purified Rhus laccase and commercial Denilite laccase were also compared and contrasted with their Chinese lacquer sap equivalents.

Does Donglan lacquer tree belong to Rhus vernicifera species?

The lacquer trees in Donglan of Guangxi Province, China, were identified totally as the species Rhus succedanea found in Vietnam and Taiwan region, based on the results of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), an easy and effective method to identify species of trees among those with similar properties. Analyses by IR and NMR, the drying properties, and conventional morphology also confirmed that the Donglan lacquer trees do not belong to Rhus vernicifera, like most trees of the China mainland. Some differences, however, such as the enzymatic activity and the components of the lacquer, were found between the Donglan lacquer and the Vietnam lacquer. The Donglan lacquer has a shorter drying time than the latter.

Quaternized chitosan/alginate nanoparticles for protein delivery.

Quaternized chitosan (QCS)/alginate (AL) nanoparticles (QCS/AL) were successfully prepared in neutral condition for the oral delivery of protein. The physicochemical structure of the QCS/AL nanoparticles was characterized by IR spectroscopy and transmission electron microscopy. The diameter of the nanoparticles with a positive surface charge was about 200 nm. The load of bovine serum albumin (BSA) was affected by the concentration and the molecular parameters, i.e. degree of substitution (DS) and weight-average molecular weight (Mw) of QCS, as well as the concentration of BSA. The release of BSA from nanoparticles was pH-dependent. Quick release occurred in 0.1M phosphate buffer solution (PBS, pH=7.4), while the release was slow in 0.1M HCl (pH=1.2). The DS and Mw of QCS play important roles in the release of BSA in vitro. QCS with high Mw accelerated the release of BSA in acid, while high DS retarded the release of BSA in both 0.1M HCl and 0.1M PBS.

Chitosan nanoparticle as gene therapy vector via gastrointestinal mucosa administration: results of an in vitro and in vivo study.

This study was designed to investigate the in vitro and in vivo transfection efficiency of chitosan nanoparticles used as vectors for gene therapy. Three types of chitosan nanoparticles [quaternized chitosan -60% trimethylated chitosan oligomer (TMCO-60%), C(43-45 KDa, 87%), and C(230 KDa, 90%)] were used to encapsulate plasmid DNA (pDNA) encoding green fluorescent protein (GFP) using the complex coacervation technique. The morphology, optimal chitosan-pDNA binding ratio and conditions for maximal in vitro transfection were studied. The in vivo transfection was conducted by feeding the chitosan/pDNA nanoparticles to 12 BALB/C-nu/nu nude mice. Both conventional and TMCO-60% could form stable nanoparticles with pDNA. The in vitro study showed the transfection efficiency to be in the following descending order: TMCO-60%>C(43-45 KDa, 87%)>C(230 KDa, 90%). TMCO-60% proved to be the most efficient and the optimal chitosan/pDNA ratio being 3.2:1. In vivo study showed most prominent GPF expression in the gastric and upper intestinal mucosa. GFP expression in the mucosa of the stomach and duodenum, jejunum, ileum, and large intestine were found, respectively, in 100%, 88.9%, 77.8% and 66.7% of the nude mice examined. TMCO-60%/pDNA nanoparticles had better in vitro and in vivo transfection activity than the other two, and with minimal toxicity, which made it a desirable non-viral vector for gene therapy via oral administration.

Optical nonlinear absorption and refraction of CdS and CdS-Ag core-shell quantum dots.

The CdS and CdS-Ag core-shell quantum dots (QDs) have been prepared. The nanostructures of the QDs were revealed by transmisson electron microscopy and absorption spectra, respectively. The third-order nonlinear optical properties of the core-shell QDs have been studied by using Z-scan technique with femtosecond pulses at the wavelength of 790 nm. The value of the effective nonlinear absorption coefficient beta(eff) of CdS-Ag QDs is measured to be about 16.8 cm/GW, which is about 400 times larger than that of bare CdS QDs of 3.9 x 10(-2) cm/GW. The nonlinear refraction index gamma of CdS-Ag QDs is about -2.3 x 10(-4) cm(2)GW, which is about 200 times larger than that of bare CdS QDs of 1.0 x 10(-6) cm(2)GW.

CdSe/ZnS-labeled carboxymethyl chitosan as a bioprobe for live cell imaging.

A simple and convenient method for the construction of CdSe/ZnS-labeled polysaccharides as bioprobes were developed, which are highly biocompatible and photostable, and have been proven to be suitable for live cell imaging.

Ionically crosslinked alginate/carboxymethyl chitin beads for oral delivery of protein drugs.

Complex beads composed of alginate and carboxymethyl chitin (CMCT) were prepared by dropping aqueous alginate-CMCT into an iron(III) solution. The structure and morphology of the beads were characterized by IR spectroscopy and scanning electron microscopy (SEM). IR confirmed electrostatic interactions between iron(III) and the carboxyl groups of alginate as well as CMCT, and the binding model was suggested as a three-dimensional structure. SEM revealed that CMCT had a porous morphology while alginate and their complex beads had a core-layer structure. The swelling behavior, encapsulation efficiency, and release behavior of bovine serum albumin (BSA) from the beads at different pHs were investigated. The BSA encapsulation efficiency was fairly high (>90%). It was found that CMCT disintegrated at pH 1.2 and alginate eroded at pH 7.4 while the complex beads could effectively retain BSA in acid (>85%) and reduce the BSA release at pH 7.4. The results suggested that the iron(III)-alginate-CMCT bead could be a suitable polymeric carrier for site-specific protein drug delivery in the intestine.

[Metabolic pathways of dipfluzine in rats].

AIM: To investigate the metabolic pathways of dipfluzine in rats. METHODS: After an oral dose of dipfluzine (80 mg x kg(-1)) to rats, urine was collected for 12 h. The metabolites of dipfluzine in urine were chromatographed and identified by LC/DAD/MS methods. RESULTS: In the rat urine, there were 1-(4-fluorophenyl)-4-piperazinylbutanone and its glucuronide, 4-hydroxybenzophenone and its glucuronide, 4-fluoro-gamma-hydroxybenzenebutanoic acid and its glucuronide and sulfate, diphenylmethanol and its glucuronide, dipfluzine, and benzophenone. CONCLUSION: In rats, dipfluzine was mainly metabolized in the pathways of N-desalkylation at 1- and 4-positions of piperazine ring. Some of metabolites were further conjugated with glucuronic acid and/or sulfuric acid.

The effects of carboxymethylated chitosan on metalloproteinase-1, -3 and tissue inhibitor of metalloproteinase-1 gene expression in cartilage of experimental osteoarthritis.

The aim of this study was to evaluate the effects of intra-articular injection of carboxymethylated chitosan (CMCTS) on mRNA expression of matrix metalloproteinase-1, -3 (MMP-1, -3) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in cartilage of osteoarthritis (OA). 32 white rabbits underwent unilateral anterior cruciate ligament transection (ACLT) and were randomly divided into four groups 5 weeks after transection. Rabbits of group A received 0.3 ml intra-articular injection of 2% high molecular weight CMCTS, once 2 weeks. Rabbits in group B were treated under the same condition using 2% CMCTS with low molecular weight. Group C rabbits received 0.3 ml of intra-articular 1% sodium hyaluronate (HA) injection, once a week. Animals of group D were not injected as controls after ACLT. At death, 11 weeks following surgery, the mRNA expressions of MMP-1, MMP-3 and TIMP-1 of degenerative cartilage were analyzed using reverse transcription-polymerase chain reaction. The mRNA levels of MMP-1 and MMP-3 in cartilage of CMCTS injection groups were significantly lower than those of HA-treated group and untreated group. There was no significant difference in MMP-1 and MMP-3 expression between the different molecular weight CMCTS injection groups. No significant difference in MMP-1 and MMP-3 expression in cartilage was found between HA injection group and control group. No significant difference in TIMP-1 expression was observed in cartilages of any group. CMCTS may significantly suppress the mRNA expression of MMP-1 and MMP-3 in cartilage during the early stages of OA. CMCTS may have a protective effect on articular cartilage of OA.

Effect of recombinant epidermal growth factor on ocular surface re-epithelization following amniotic membrane transplantation in patients with pterygium excision.

OBJECTIVE: To observe the effect of recombinant human epidermal growth factor (rhEGF) on ocular surface re-epithelization and the efficacy of amniotic membrane transplantation in patients with pterygium. METHODS: Amniotic membrane transplantation was performed on 40 eyes of 36 patients with pterygium after removal of pterygium. All the eyes were randomly divided into 2 groups: 20 eyes received rhEGF ophthalmic solution and the other 20 drug vehicle. The healing rates of the corneal and conjunctival epithelium were observed respectively. Follow-up study lasting for 3 to 12 months was conducted in all the cases postoperatively. RESULTS: The healing rate of both the corneal and conjunctival epithelium in rhEGF-treated group (74.983+/-18.998 micrometer/h and 36.584+/-7.888 micrometer/h respectively) was significantly faster than the control (59.372+/-17.197 +/-m/h and 29.18+/-5.450 micrometer/h respectively, P<0.01 for both comparisons). Follow-up witnessed no recurrence of the disease. CONCLUSIONS: rhEGF effectively promotes the healing of ocular surface epithelium defect, and amniotic membrane transplantation is a good surgical procedure for treating pterygium.