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Complexation of isotactic, syndiotactic, and atactic poly(methacrylic acid), PMA, with trivalent lanthanide ions has been studied in water at a degree of neutralization 0.5. Metal ion binding is shown by quenching of cerium(III) fluorescence, enhancement of Tb(III) luminescence, and lanthanide-induced line broadening in the PMA (1)H NMR spectra. Comparison with lanthanide-acetate complexation suggests carboxylate binds in a bidentate fashion, while Ce(III) luminescence quenching suggests an ≈3:1 carboxylate:metal ion stoichiometry, corresponding to charge neutralization. The presence of both free and bound Ce(III) cations in PMA solutions is confirmed from luminescence decays. Studies of Tb(3+) luminescence lifetime in H2O and D2O solutions show complexation is accompanied by loss of 5-6 water molecules, indicating that each bidentate carboxylate replaces two coordinated water molecules. The behavior depends on pH and polyelectrolyte stereoregularity, and stronger binding is observed with isotactic polyelectrolyte. Binding of cetylpyridinium chloride, CPC, in these systems is studied by luminescence, NMR, and potentiometry. NMR and Tb(3+) luminescence lifetime studies show the strongest binding with the isotactic polymer. Binding of surfactant to poly(methacrylate) in the presence of lanthanides is noncooperative, i.e., it binds to the free sites; binding isotherms in the presence of lanthanides are shifted to higher free surfactant concentrations, compared with sodium ions, have lower slopes and show a clear two-step binding mechanism. While CPC readily replaces the Na(+) ions of poly(methacrylate) and binds very strongly (low critical association concentrations), exchange is much more difficult with the strongly bound trivalent lanthanide ions. Effects of tacticity are seen, with surfactant interacting most strongly with isotactic chains in the initial stages of binding, while in the final stages of binding the interaction is strongest with atactic poly(methacrylate).

Objective: To describe the learning curve of rheumatologists with limited experience using ultrasound (US) attending an intensive disease-oriented training program focusing on the skills required to obtain and interpret US signs of monosodium urate (MSU) crystal deposits in joint and periarticular tissues., Methods: Three investigators participated in a 7-day training program involving 12 men with gout. The agreement between the expert and beginners was calculated in 4 sessions involving 8 patients with gout. The US assessment was performed at the second and third metacarpophalangeal joints, knee, tibiotalar and first metatarsophalangeal joints, second and third finger flexors, quadriceps and patellar posterior tibialis, peroneus longus and brevis, and Achilles tendons. The presence or absence of synovial fluid/synovial hypertrophy, double contour sign, intra- or periarticular and intratendinous tophi, bursitis, bone erosions, and tendon tears was recorded., Results: A total of 416 anatomic sites were studied. Kappa values and overall agreement percentages of qualitative assessments of US gout findings at the end of the exercise both showed moderate to excellent agreement, while in the first session they showed poor/fair agreement. At the end of the training session, sensitivity, specificity, and capability of the beginners were also improved., Conclusion: After 1 week of the disease-oriented training program, rheumatologists with limited experience in US were satisfactorily able to detect and interpret the main US signs indicative of MSU crystal deposits at different tissues in patients with gout., (Copyright © 2013 by the American College of Rheumatology.)

Objectives: Characterize Osteoarticular Brucellosis in the University Hospital of Coimbra (HUC) in the past decade., Material and Methods: A retrospective study of the cases diagnosed between January/2000 and December/2009 in the HUC., Results: Ninety patients were admitted with the dia-gnosis of brucellosis in our hospital, of whom 44 (49%; 18 men; 26 women, mean 49.5 years) had osteoarticular complications. Twenty-five (45%) patients had a positive epidemiological context. The most frequent clinical manifestation was local pain (73%) followed by polyarthralgias and constitutional symptoms. The C-reactive protein was the inflammatory marker most often increased (82%). The Rose Bengala test was positive in 42 patients, and a Wright's sero-aglutination above than 1/160 was detected in 28 patients. An etiologic agent was isolated in 28 (64%) patients, with 70% of positive blood cultures. The imaging procedure of choice was magnetic resonance imaging (MRI) (46%). The osteo-articular manifestation most frequent was spondylodiscitis (57%) with a lumbosacral involvement in 40%. All patients completed antibiotic therapy. One patient underwent surgery to drain the abscess. Patients had an average length of admission of 28.3 days, with a good outcome in 60%, and a reasonable outcome in 20%, despite 20% of the patients lost follow-up., Conclusions: Brucellosis is a disease of obligatory declaration not eradicated in Portugal, with a great impact on socio-economic and public health. So, this epidemiological knowledge of brucellosis cases, allows an early intervention and therapy.