Enhanced reactivity to pain in patients with rheumatoid arthritis

Introduction  

Maladaptive physiological responses to stress appear to play a role in chronic inflammatory diseases such as rheumatoid arthritis (RA). However, relatively little stress research in RA patients has involved the study of pain, the most commonly reported and most impairing stressor in RA. In the present study, we compared psychophysical and physiological responses to standardized noxious stimulation in 19 RA patients and 21 healthy controls.     

A Demineralization Procedure for Enzymatic Histochemical Use: A Quantitative Succinic Dehydrogenase Assay

Thinnest practical slices of bones or teeth are suspended at 4 C in a 10% solution of EDTA in 0.1 M tris buffer brought to pH 6.95 with KOH pellets. The solution is stirred moderately and continuously with a magnetic stirrer until specimens are demineralized. Unwashed specimens, taken directly from the demineralizing fluid, are frozen on a block of CO₂ ice, mounted on a tissue carrier and sectioned at 6 μ in a cryostat. Histochemical stains conducted on sections stored in a slide holder enclosed in a plastic bag in a refrigerator for as long as 2 wk were successful. Quantitative studies on the preservation of succinic dehydrogenase showed nearly all of it present in specimens demineralized for 2 days, and approximately 50% remaining in specimens demineralized for 7 days. Qualitative studies with other dehydrogenases indicate that several may be similarly affected.