[Adhesion and growth of human periodontal ligament cells on hyaluronic acid/collagen scaffold].

Objective: The adhesion and growth of human periodontal ligament cells (PDLC) on collagen (Col), hyaluronic acid (HA) and HA/Col scaffolds were studied to evaluate the feasibility of HA/Col as a scaffold material in periodontal tissue engineering.

Methods: Human PDLC cultured in vitro was collected and seeded on Col, HA, HA/Col scaffolds crosslinked by carbodiimide. The influences of scaffolds on cell adhesion and growth were observed by MTT assay.

Gellan gel beads containing magnetic nanoparticles: an effective biosorbent for the removal of heavy metals from aqueous system.

This study describes an efficient adsorbent consisting of magnetic Fe(3)O(4) and gellan gum, which couples magnetic separation with ionic exchange for heavy metal removal. Adsorption kinetics analysis showed that the adsorption capacities were in an order of Pb(2+)>Cr(3+)>Mn(2+). Different experimental parameters studies indicated that adsorbent dosage, initial metal concentration, temperature and initial pH played important roles in adsorption process.

Overexpression of Tiam1 in hepatocellular carcinomas predicts poor prognosis of HCC patients.

Little research has been done to test the usefulness of T-lymphoma invasion and metastasis 1 (Tiam1) as a prognostic marker for hepatocellular carcinoma (HCC). In this study, we investigated Tiam1 expression and its prognostic value for HCC. HCC surgical tissue samples were taken from 152 HCC patients who had been followed up for 5 years.

Structures of two coronavirus main proteases: implications for substrate binding and antiviral drug design.

Coronaviruses (CoVs) can infect humans and multiple species of animals, causing a wide spectrum of diseases. The coronavirus main protease (M(pro)), which plays a pivotal role in viral gene expression and replication through the proteolytic processing of replicase polyproteins, is an attractive target for anti-CoV drug design. In this study, the crystal structures of infectious bronchitis virus (IBV) M(pro) and a severe acute respiratory syndrome CoV (SARS-CoV) M(pro) mutant (H41A), in complex with an N-terminal autocleavage substrate, were individually determined to elucidate the structural flexibility and substrate binding of M(pro).

Interface reaction route to two different kinds of CeO2 nanotubes.

CeO(2) nanotubes have been synthesized with a simple solid-liquid interface reaction route in the absence of any surfactants. Although the basic reaction principles are similar, two kinds of nanotubes with completely different morphologies and structures can be generated by slightly tuning the postprocessing conditions. The first formation involves employing Ce(OH)CO(3) nanorods as both the physical and chemical templates, and the other requires layered Ce(OH)3 as an anisotropic intermediate species.

[Distribution of five periodontal pathogens in subgingival plaque in chronic periodontitis].

Objective: To investigate the distribution of H. actinomycetemcomitans, P. gingivalis, P.

[Effects of growth factors on periodontal ligament cells].

Objective: To evaluate the effects of the polypeptide growth factors on the periodontal ligament cell (PDLC) based on a comprehensive review on the literature concerned.

Methods: The recent literature related to the effects of the polypeptide growth factors on the PDLC were extensively and comprehensively reviewed and a corresponding evaluation was made.

Results: The proliferation and the multi-directional differentiation of the PDLC were found to be the basis for the regeneration of the periodontal tissues.

Low temperature CO oxidation over unsupported nanoporous gold.

Supported Au nanoclusters are well-known for their unusual properties in catalysis. We describe here that nanostructured porous Au made via dealloying represents a new class of unsupported catalysts with extraordinary activities in important reactions such as CO oxidation. Although nanoporous Au may contain some oxides on the surface, our results demonstrate that it is metallic Au that plays the main role in this catalytic reaction.

[Effect of triptolide on expression of urokinase-type plasminogen activators in vascular endothelial cells].

Background & Objective: It has been showed that triptolide (T10) has antitumor activities. This study was to observe the inhibitory effects of T10 on proliferation of vascular endothelial cells and expression of urokinase-type plasminogen activator (u-PA), and to elucidate the antiangiogenic mechanism of T10.

Methods: Human umbilical vein endothelial cells were cultured in vitro for 3 generations, and treated with T10 (0, 5, 10, 20, and 30 microg/L), or dexamethasone (300 mg/L) as control.

[Effects of triptolide on migration of vascular endothelial cells].

Objective: To investigate the inhibitory effects of triptolide on the migration, gene and protein expression of urokinase-type plasminogen activator (u-PA) of endothelial cells (ECs) cultured in vitro and to elucidate the anti-angiogenic mechanism of triptolide.

Methods: Human umbilical vein endothelial cells (HUVECs) were cultured in vitro and the passage 3 cells were treated with triptolide (0, 5, 10, 20, 30 microg/L). Three-dimensional culture system was used to assess the effect of triptolide on the migration of HUVECs.

A new approach to investigate the pharmacokinetics of traditional chinese medicine YL2000.

Much progress has been made in the pharmacology of Traditional Chinese Medicine (TCM). However, the question on how to investigate pharmacokinetics of TCM extract remains. In this study, we selected a new TCM extract YL2000 developed in our laboratory as the research object and investigated both the pharmacokinetics of baicalin and berberine in YL2000 and the pharmacodynamics of YL2000 in febrile rats.

Site-directed mutagenesis and preliminary x-ray crystallographic studies of the tabtoxin resistance protein.

Tabtoxin resistance protein (TTR) is an enzyme that catalyzes the acetylation of tabtoxin rendering tabtoxin-producing pathogens tolerant to their own phytotoxins. According to the structure based detoxification mechanism of TTR, three site-directed mutants Y141F, D130N and Y141F-D130N were constructed and overexpressed in E. coli.

Crystal structure of tabtoxin resistance protein complexed with acetyl coenzyme A reveals the mechanism for beta-lactam acetylation.

Tabtoxin resistance protein (TTR) is an enzyme that renders tabtoxin-producing pathogens, such as Pseudomonas syringae, tolerant to their own phytotoxins. Here, we report the crystal structure of TTR complexed with its natural cofactor, acetyl coenzyme A (AcCoA), to 1.55A resolution.

Affinity alkylation of the Trp-B4 residue of the beta -subunit of the glutaryl 7-aminocephalosporanic acid acylase of Pseudomonas sp. 130.

Glutaryl 7-aminocephalosporanic acid acylase of Pseudomonas sp. 130 (C130) was irreversibly inhibited in a time-dependent manner by two substrate analogs bearing side chains of variable length, namely 7beta-bromoacetyl aminocephalosporanic acid (BA-7-ACA) and 7beta-3-bromopropionyl aminocephalosporanic acid (BP-7-ACA). The inhibition of the enzyme with BA-7-ACA was attributable to reaction with a single amino acid residue within the beta-subunit proven by comparative matrix assisted laser desorption/ionization-time of flight mass spectrometry.