Acute arthritis after intra-articular hyaluronate injection: onset of effusions without crystal.

Side effects of intra-articular hyaluronate injection include aseptic acute arthritis, which develops within hours after injection. Based on standard crystal analysis, calcium crystal shedding has been postulated to explain this complication. However, it is not known whether apatite crystals or low amounts of calcium pyrophosphate dihydrate (CPPD) crystals are also involved as to determine this requires a complete synovial fluid (SF) analysis. Two cases of such an acute arthritis are reported in patients after receiving a second Hylan GF-20 intra-articular injection. The SF did not contain CPPD, monosodium urate, or calcium apatite microcrystals as examined by microscopic analysis (using a compensated polarised light microscope) after alizarin red staining. Further studies are required to investigate possible direct proinflammatory effects of hyaluronic acid degradation products.

Nitric oxide in rheumatology.

Nitric oxide (NO) is attracting considerable interest because it mediates many functions. This gas is ubiquitously produced in the body by three enzymes, called NO synthases. Two NO synthases are constitutively expressed, one in the nervous system and the other in the blood vessels, where it regulates tissue perfusion. The third NO synthase can be induced by several stimuli (bacterial endotoxins, cytokines), most notably in inflammatory cells and chondrocytes. The effects of NO produced by the inducible NO synthase range from T-cell response modulation to formation of free radicals responsible fortissue damage and cartilage matrix degradation. Administration of NO synthase inhibitors in animal models of arthritis yields ambiguous effects, often with prevention of arthritis, but sometimes with worsening of established arthritis. The data available to date do not support the use of such inhibitors in the treatment of human arthritis.

[Angiographic morphological study of the left ventricle in obstructive cardiomyopathy. Comparison with haemodynamic data (author's transl)]. / Etude angiographique de la morphologie du ventricule gauche dans la myocardiopathie obstructive. Comparaison avec les résultats hémodynamiques.

The right anterior oblique ventriculographs of 20 patients with obstructive cardiomyopathy were reviewed, and the images obtained during systole were divided into three groups: (1) bilocular left ventricular cavity with midventricular stenosis; (2) obliteration of the ventricle reduced to its infra-sigmoidal portion, with atrophy or even amputation of the apical portion; and (3) subnormal image. Haemodynamically, the most common abnormality (5/8 patients) in group 1 was the presence of a gradient in the basal state. In group 2, this gradient was only found in 2/8 patients, but the left ventricular telediastolic pressure was much higher in the basal state or after stimulation than in group 1. Haemodynamic changes were moderate in group 3. The abnormalities in left ventricular telediastolic pressure in this type of cardiomyopathy are interpreted as reflecting disorders in compliance which would then be maximal in group 2. This study is part of an attempt to classify the various characteristics of the left ventricle with the view of identifying some forms amenable to surgical treatment.