Chemical Reactions and Phase Stabilities in the Si-Te System at High Pressures and High Temperatures.

Chemical reactions and phase stabilities in the Si-Te system at high pressures were explored using angle-dispersive synchrotron powder diffraction in a large-volume multianvil press together with density functional theory-based calculations. Cubic and rhombohedrally distorted clathrates, with the general formula Te@(SiTe) and wide compositional range, preceded by a hexagonal phase with the composition SiTe, are formed for different mixtures of Si and Te as starting materials. SiTe, with the structural formula Te(TeSi)(TeSi), is the very first chalcogenide with the MnSi-type structure.

Proximal femoral allografting in revision total hip arthroplasty: stabilization of the host-graft junction with tension band fixation.

Large deficiencies of the metaphysis and proximal diaphysis present a significant challenge to the orthopaedic surgeon undertaking revision of failed total hip arthroplasty. Proximal femoral allograft-prosthetic reconstruction may enable revision in such situations. Secure fixation is essential to successful integration and function of these allograft-prosthetic constructs.

Modulation of the catabolic effects of interleukin-1 beta on human articular chondrocytes by transforming growth factor-beta.

The effects of IL-1 beta and TGF-beta on the biosynthesis of extracellular matrix structural components relative to the metalloproteinases and their inhibitor TIMP1 in human articular chondrocytes were investigated. It has been proposed that TGF-beta, acting as a positive regulator of matrix accretion, can counteract the increased loss of cartilage matrix induced by IL-1 beta. To allow a comparison of their effects on mRNA levels for these different components, quantitation by competitive RT/PCR was employed.

Human cartilage gp-39, a major secretory product of articular chondrocytes and synovial cells, is a mammalian member of a chitinase protein family.

One of the major secreted proteins of human articular chondrocytes in monolayer or explant culture and of synovial fibroblasts is a glycoprotein with an apparent molecular weight of approximately 39,000, referred to as human cartilage glycoprotein-39 (HC gp-39). The protein was purified, and its complete cDNA sequence was determined. It contained an open reading frame coding for a 383-amino acid long peptide.