Reactive oxygen species depolymerize hyaluronan: involvement of the hydroxyl radical.

We have previously demonstrated that reactive oxygen species (ROS) are involved in cartilage degradation. A decrease in the size of hyaluronan (HA), which is the major macromolecule in synovial fluid and is responsible for imparting viscosity to it, is reported in arthritis patients. The purpose of this study is to determine the ROS that depolymerize HA.

Bridging a 30-mm nerve defect using collagen filaments.

This article describes a 30-mm regeneration of severed peripheral nerve axons along collagen filaments. Two thousand or 4000 31-mm-long collagen filaments were grafted to bridge a 30-mm defect of the rat sciatic nerve. A collagen tube was grafted as a control.

Bridging a spinal cord defect using collagen filament.

Study Design: A rat model of spinal cord defect was designed to evaluate the effect of collagen filament implant on nerve regeneration in the spinal cord defect.

Objectives: To bridge a spinal cord defect and restore the function in adult mammals.

Summary Of Background Data: Resection of the spinal cord in mammals is always followed by motor paralysis and loss of voluntary function below the lesion.

Structure and physicochemical properties of diastereomeric isomers of ApA.

Heterochiral ApAs (ALpAD and ADpAL) together with homochiral D-(ApA) and L-(ApA) were synthesized and their helical structures were investigated by using spectroscopic techniques. The results indicate that the chirality of the 3'-end residue is the primary determinant for the helical sense of adenylyl-(3'-5')-adenosine (ApA).

Thermodynamic study of hybridization properties of heterochiral nucleic acids.

Heterochiral DNA and RNA heptamers, which contained an unnatural L-nucleotide, were synthesized, and thermodynamic analyses of their hybridization properties with complementary DNA and RNA strands were systematically conducted by UV melting experiments. The results clearly demonstrated that the incorporation of an L-ribonucleotide into the RNA strand leads to more significant destabilization of the duplexes than that of an L-deoxyribonucleotide into the DNA strand, regardless of whether the complementary strand is DNA or RNA. The destabilization of the duplexes by the substitution of D-thymidine with L-thymidine in the DNA strand is entropically driven, whereas that by the substitution of D-uridine with L-uridine in the RNA strand is enthalpically driven.

Non-enzymatic oligomerization of racemic adenosine 5'-phosphorimidazolide on Na(+)-montmorillonite.

In this study, we have investigated non-enzymatic oligomerization of an activated racemic mononucleotide in the presence of Na(+)-montmorillonite. Oligomers up to the decamer in length were formed by oligomerization reactions of activated D- and L-mononucleotides. Similarly, oligomerization of an activated racemic mononucleotide results in the formation of oligomers up to the octamer.

Anti-HIV-1 activity of L-DNA quadruplex.

Zintevir is a DNA 17mer that forms a quadruplex and shows strong anti-human immunodeficiency virus (HIV)-1 activity. The quadruplex formation is thought to be essential for the anti-HIV-1 activity of Zintevir. We synthesized the enantiomer of Zintevir and evaluated its structure and anti-HIV-1 activity.

Validation of acetabular cup wear volume based on direct and two-dimensional measurements: hip simulator analysis.

The volumetric wear in retrieved cups can be assessed by mathematical conversion based on linear measurements and by a fluid-displacement method. We used a hip simulator model to produce wear in 22-, 28-, and 32-mm hip implants and then assessed the volumetric wear using a gravimetric wear method. We then compared the findings with those obtained with the linear and fluid-displacement methods.

In vivo three-dimensional patellar tracking on the femur.

In vivo three-dimensional patellar tracking under weightbearing conditions was investigated with the principal reference axes of the femur in the coronal and axial planes, using a biplanar image-matching technique. Three-dimensional knee models of eight healthy volunteers were constructed using computed tomography scanning. Projection images of the models were fitted onto anteroposterior and lateral radiographs of the knees at hyperextension and at every 15 degrees from 0 degrees to 120 degrees flexion.

Cyclooxygenase-2 is up-regulated by interleukin-1 beta in human colorectal cancer cells via multiple signaling pathways.

Overexpression of cyclooxygenase-2 (COX-2) has been observed in human colorectal cancer. COX-2 expression in human tumors can be induced by growth factors, cytokines, oncogenes, and other factors. The mechanisms regulating COX-2 expression in human colon cancer have not been completely elucidated.

Characterization of DNA, RNA and DNA/RNA duplexes containing an L-nucleotide.

In order to investigate the duplex structure of DNA and RNA containing an L-nucleotide residue, we carried out the UV-melting and CD experiments. Although the introduction of an L-nucleotide into DNA/DNA, DNA/RNA and RNA/RNA duplexes reduced their Tm values, the typical two-state transitions were observed for all of the duplexes. The incorporation of an L-nucleotide into the RNA strand caused more remarkable decreases of the Tm value than that into the DNA strand.

Involvement of arachidonic acid in nonimmunologic production of superoxide in mast cells.

Background: A number of different molecules are known to be involved in the signal pathway to release histamine from mast cells, among which arachidonic acid (AA) is one of the key mediators. On the other hand, we found that the application of compound 48/80, a typical histamine liberator, generated superoxide in mast cells. In the present study, we investigated the mechanism of superoxide production in mast cells with respect to AA signaling in conjunction with a fine structural analysis.

Induction of neuropilin-1 and vascular endothelial growth factor by epidermal growth factor in human gastric cancer cells.

The epidermal growth factor receptor (EGF-R) pathway plays a pivotal role in the progression of human gastric cancer. The angiogenic factor vascular endothelial growth factor (VEGF) has been shown to be induced by EGF in various cancer cell lines. Neuropilin-1 (NRP-1) acts as a coreceptor for VEGF-165 and increases its affinity for VEGF receptor 2 (VEGFR-2) in endothelial cells.

Biology of angiogenesis in tumors of the gastrointestinal tract.

The realization that the growth and spread of tumors are dependent on angiogenesis has created new avenues of research designed to help us to better understand cancer biology and to facilitate the development of new therapeutic strategies. However, the process of angiogenesis consists of multiple, sequential, and interdependent steps with a myriad of positive and negative regulators of angiogenesis being involved. The survival of tumors and thus their metastases are dependent upon the balance of endogenous angiogenic and anti-angiogenic factors such that the outcome favors increased angiogenesis.

Lectin-like oxidized low-density lipoprotein receptor 1 mediates leukocyte infiltration and articular cartilage destruction in rat zymosan-induced arthritis.

Objective: The relationship between rheumatoid arthritis and atherosclerosis has been recognized for >20 years. This study aimed to elucidate the roles of oxidized low-density lipoprotein (ox-LDL; one of the main pathogenic factors of atherosclerosis) and its endothelial receptor, lectin-like ox-LDL receptor 1 (LOX-1), in arthritic joints using a rat zymosan-induced arthritis (ZIA) model.

Methods: LOX-1 expression and ox-LDL accumulation in arthritic joints were detected by immunohistochemistry using specific mouse anti-LOX-1 and anti-ox-LDL monoclonal antibodies, respectively.

Age-associated changes in arterial elastic properties in children.

Unlabelled: Age-associated changes in pulsatile components of the arterial system in normal children have not previously been studied. The purpose of the present study was to establish reference ranges for age-associated changes in arterial pulsatile properties in children. Arterial compliance (C(A)) and stiffness of the proximal aorta were estimated from data obtained by cardiac catheterisation in 112 paediatric patients (age range, 6 months to 20 years) who were considered to have normal systemic vascular beds.

30 mm regeneration of rat sciatic nerve along collagen filaments.

This paper describes 30 mm regeneration of peripheral nerve axons along collagen filaments; 31-mm-long collagen filaments or collagen tube were grafted to bridge a 30-mm defect of rat sciatic nerve. The mean number and the diameter of regenerated myelinated axons were 330+/-227 and 2.7+/-0.

A mechanical comparison of 2 posterior-stabilizing designs: Insall/Burstein 2 knee and Bisurface knee.

A posterior-stabilizing knee prosthesis, called the Bisurface knee (Kyocera Corp, Kyoto, Japan), with a ball-and-socket joint installed in the midposterior portion of the tibiofemoral joint, has been developed to satisfy 2 conflicting demands in knee joint design: kinematics and wear resistance. To confirm if the prosthesis has achieved its design objectives, a contact area and stress study was done throughout the range of motion and compared with results obtained for the Insall-Burstein 2 knee. The posterior-stabilizing ability of the ball-and-socket joint also was assessed.

Role of angiogenesis in the development and growth of liver metastasis.

Cancer metastasis is a highly complex process that involves aberrations in gene expression by cancer cells leading to transformation, growth, angiogenesis, invasion, dissemination, survival in the circulation, and subsequent attachment and growth in the organ of metastasis. Angiogenesis facilitates metastasis formation by providing a mechanism to (1) increase the likelihood of tumor cells entering the blood circulation and (2) provide nutrients and oxygen for growth at the metastatic site. The formation and establishment of metastatic lesions depend on the activation of multiple angiogenic pathways at both primary and metastatic sites.

A modification of the retrograde medullary screw for the treatment of bilateral pubic ramus nonunions: a case report.

We describe a patient with bilateral pubic ramus nonunions who was treated successfully with a modification of the retrograde medullary screw technique, in which the screw orientation was altered so that it engaged the cancellous bone in the inferior part of the anterior column and the anterior-inferior cortex of the fossa acetabuli. The modification should be one option when the original technique is judged to be difficult to perform.

Helical structure of heterochiral RNA dimers: helical sense of ApA is determined by chirality of 3'-end residue.

Heterochiral ApAs (ALpAL and ALpAL) have been synthesized and investigation of their helical structures by means of spectroscopic techniques indicates that the chirality of the 3'-end residue is the primary factor for determining the helical sense of ApA.

Synopsis of angiogenesis inhibitors in oncology.

Angiogenesis is a dynamic process essential for primary tumor growth and metastases. New insights into the basic understanding of the biologic processes responsible for angiogenesis have led to the characterization of potential therapeutic targets. Several strategies for the development of antiangiogenic therapeutic modalities have been employed, including agents that (1) decrease the activity of specific angiogenic factors, (2) decrease th$ activity of endothelial survival factors, (3) increase the activity of naturally occurring antiangiogenic agents, or (4) indirectly downregulate angiogenic and survivalfactor activity.

Inhibitory effect of olopatadine on antigen-induced eosinophil infiltration and the LFA-1 and Mac-1 expression in eosinophils.

The inhibitory effect of olopatadine, a new antiallergic drug, on antigen-induced eosinophil infiltration and its mechanisms were examined using the local sensitized rat allergic rhinitis model and isolated IL-5-stimulated rat peritoneal eosinophils. Olopatadine dose-dependently inhibited antigen-induced eosinophil infiltration in the nasal mucosa. Olopatadine dose-dependently repressed the IL-5-induced expressions of CD11a/CD18 (LFA-1) and CD11b/CD18 (Mac-1) on rat peritoneal eosinophils.

A practical synthesis of L-ribose.

L-Ribose was synthesized by a simple four-step method with overall yield of 76.3% from a protected L-arabinose derivative, which is a compatible intermediate for the synthesis of L-deoxyribose. The key step of this strategy is the Swern oxidation and subsequent stereoselective reduction accompanied by inversion of the 2-hydroxy group of protected L-arabinose.

Functional analysis of the effect of the posterior stabilising cam in two total knee replacements. A comparison of the Insall/Burstein and Bisurface prostheses.

The Bisurface knee prosthesis (BP) has a posterior stabilising cam (ball-and-socket joint) in the mid-posterior region of the femorotibial joint in an attempt to improve the range of movement. Based on an in vitro weight-bearing study contact areas of the Insall/Burstein 2 (IB2) and the BP knee were compared using pressure-sensitive films. The stability afforded by the cam was evaluated by means of dislocation distances in the vertical and horizontal planes.