Portal systemic shunt through the renal vein

BACKGROUND

Despite the semi-routine use of color Doppler sonography for evaluating portal circulation abnormalities, there is a relative paucity of detailed color Doppler findings of portal systemic (P-S) shunt through the renal vein (P-SR shunt).

METHODS

We reviewed the color Doppler findings of 18 patients with P-SR shunt to determine its clinical significance and appropriate scanning techniques for diagnosing accurately P-SR shunt.

RESULTS

The splenorenal shunt was imaged as a highly tortuous vessel at the splenic hilum, which then coursed backward behind the spleen. Splenic vein flow was reversed or very slow. The gastrorenal shunt originated from the splenic vein, coursed backward, and joined the left renal vein. Flow direction in the splenic vein was always hepatopetal. The P-S shunt through the right renal vein originated from duodenal or jejunal varices, coursed posterolaterally, and joined the right renal vein at the renal hilum.

CONCLUSION

Familiarity with these color Doppler findings will help increase the diagnostic confidence of P-SR shunt by color Doppler sonography.

Structural characterization of the metal/glass interface in bioactive glass coatings on Ti-6Al-4V

Coating Ti-based implants with bioactive materials promotes joining between the prostheses and the bone as well as increasing long-term implant stability. In the present work, the interface between Ti-6Al-4V and bioactive silicate glass coatings, prepared using a simple enameling technique, is analyzed. High-resolution transmission electron microscopy of the glass/alloy interface shows the formation of a reaction layer ( approximately 150 nm thick) composed of Ti5Si3 nanoparticles with a size of approximately 20 nm. This nanostructured interface facilitates the formation of a stable joint between the glass coating and the alloy.

Autoantibodies to calpastatin (an endogenous inhibitor for calcium-dependent neutral protease, calpain) in systemic rheumatic diseases

We identified an autoantibody that reacts with calpastatin [an inhibitor protein of the calcium-dependent neutral protease calpain (EC 3.4.22.17)]. In early immunoblot studies, sera from patients with rheumatoid arthritis (RA) recognized unidentified 60-, 45-, and 75-kDa proteins in HeLa cell extracts. To identify these autoantigens, we used patient sera to clone cDNAs from a lambda gt11 expression library. We isolated clones of four genes that expressed fusion proteins recognized by RA sera. The 1.2-kb cDNA insert (termed RA-6) appeared to encode a polypeptide corresponding to the 60-kDa antigen from HeLa cells, since antibodies bound to the RA-6 fusion protein also reacted with a 60-kDa HeLa protein. The deduced amino acid sequence of the RA-6 cDNA was completely identical with the C-terminal 178 amino acids of human calpastatin except for one amino acid substitution. Patient sera that reacted with the RA-6 also bound pig muscle calpastatin, and a monoclonal antibody to human calpastatin recognized the RA-6 fusion protein, confirming the identity of RA-6 with calpastatin. Moreover, the purified RA-6 fusion protein inhibited the proteolytic activity of calpain, and IgG from a serum containing anti-calpastatin antibodies blocked the calpastatin activity of the RA-6 fusion protein. Immunoblots of the RA-6 product detected autoantibodies to calpastatin in 57% of RA patients; this incidence was significantly higher than that observed in other systemic rheumatic diseases, including systemic lupus erythematosus (27%), polymyositis/dermatomyositis (24%), systemic sclerosis (38%), and overlap syndrome (29%). Thus, anti-calpastatin antibodies are present most frequently in patients with RA and may participate in pathogenic mechanisms of rheumatic diseases.