Mapping of citrullinated fibrinogen B-cell epitopes in rheumatoid arthritis by imaging surface plasmon resonance

Introduction  

Rheumatoid arthritis (RA) frequently involves the loss of tolerance to citrullinated antigens, which may play a role in pathogenicity. Citrullinated fibrinogen is commonly found in inflamed synovial tissue and is a frequent target of autoantibodies in RA patients. To obtain insight into the B-cell response to citrullinated fibrinogen in RA, its autoepitopes were systematically mapped using a new methodology.     

Absence of acetohydroxy acid synthetase in a clinical isolate of Neisseria gonorrhoeae requiring isoleucine and valine

A clinical isolate of Neisseria gonorrhoeae with an unusual growth requirement for isoleucine and valine lacked the activity of acetohydroxy acid synthetase, one of the enzymes required for the biosynthesis of these amino acids. A spontaneous mutant which no longer required isoleucine and valine had acquired this enzymatic activity.     

Growth hormone concentration following various factors stimulating its release]

Growth hormone concentration has been assayed in 105 children (45 girls and 60 boys) during starvation and following its stimulation with clonidine and insulin and during the sleep. A significant difference between growth hormone concentration during fasting and after stimulation has been noted. No statistically significant difference between growth hormone concentrations during the sleep and following insulin has been found. The most intensive growth hormone release has been observed during the sleep. Test with clonidine is technically simple and may be performed also in the out-patient clinics.