Adalimumab clinical efficacy is associated with rheumatoid factor and anti-cyclic citrullinated peptide antibody titer reduction: a one-year prospective study

Studies on autoantibody production in patients treated with tumor necrosis factor-α (TNF-α) inhibitors reported contradictory results. We investigated in a prospective study the efficacy of a treatment with human monoclonal anti-TNF-α antibody (adalimumab) in patients with rheumatoid arthritis (RA) and we evaluated the relationship between treatment efficacy and the incidence and titers of disease-associated and non-organ-specific autoantibodies. Fifty-seven patients with RA not responsive to methotrexate and treated with adalimumab were enrolled. Antinuclear, anti-double-stranded(ds)DNA, anti-extractable nuclear antigens, anti-cardiolipin (aCL), anti-β₂ glycoprotein I (anti-β₂GPI) autoantibodies, rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) autoantibodies were investigated at baseline and after 6 and 12 months of follow-up. Comparable parameters were evaluated in a further 55 patients treated with methotrexate only. Treatment with adalimumab induced a significant decrease in RF and anti-CCP serum levels, and the decrease in antibody titers correlated with the clinical response to the therapy. A significant induction of antinuclear autoantibodies (ANA) and IgG/IgM anti-dsDNA autoantibodies were also found in 28% and 14.6% patients, respectively, whereas aCL and anti-β₂GPI autoantibodies were not detected in significant quantities. No association between ANA, anti-dsDNA, aCL and anti-β₂GPI autoantibodies and clinical manifestations was found. Clinical efficacy of adalimumab is associated with the decrease in RF and anti-CCP serum levels that was detected after 24 weeks and remained stable until the 48th week of treatment. Antinuclear and anti-dsDNA autoantibodies, but not anti-phospholipid autoantibodies, can be induced by adalimumab but to a lower extent than in studies with other anti-TNF blocking agents.     

An acidic loop and cognate phosphorylation sites define a molecular switch that modulates ubiquitin charging activity in Cdc34-like enzymes

E2 ubiquitin-conjugating enzymes are crucial mediators of protein ubiquitination, which strongly influence the ultimate fate of the target substrates. Recently, it has been shown that the activity of several enzymes of the ubiquitination pathway is finely tuned by phosphorylation, an ubiquitous mechanism for cellular regulation, which modulates protein conformation. In this contribution, we provide the first rationale, at the molecular level, of the regulatory mechanism mediated by casein kinase 2 (CK2) phosphorylation of E2 Cdc34-like enzymes. In particular, we identify two co-evolving signature elements in one of the larger families of E2 enzymes: an acidic insertion in β4α2 loop in the proximity of the catalytic cysteine and two conserved key serine residues within the catalytic domain, which are phosphorylated by CK2. Our investigations, using yeast Cdc34 as a model, through 2.5 μs molecular dynamics simulations and biochemical assays, define these two elements as an important phosphorylation-controlled switch that modulates opening and closing of the catalytic cleft. The mechanism relies on electrostatic repulsions between a conserved serine phosphorylated by CK2 and the acidic residues of the β4α2 loop, promoting E2 ubiquitin charging activity. Our investigation identifies a new and unexpected pivotal role for the acidic loop, providing the first evidence that this loop is crucial not only for downstream events related to ubiquitin chain assembly, but is also mandatory for the modulation of an upstream crucial step of the ubiquitin pathway: the ubiquitin charging in the E2 catalytic cleft.     

Hand-held echocardiography: added value in clinical cardiological assessment

In the present article we review the main published data on the application of Tissue Doppler Imaging (TDI) to stress echocardiography for the detection of myocardial ischemia. TDI has been applied to stress echocardiography in order to overcome the limitations of visual analysis for myocardial ischemia. The introduction of a new technology for clinical routine use should pass through the different phases of scientific assessment from feasibility studies to large multicenter studies, from efficacy to effectiveness studies. Nonetheless the pro-technology bias plays a major role in medicine and expensive and sophisticated techniques are accepted before their real usefulness and incremental value to the available ones is assessed. Apparently, TDI is not exempted by this approach : its applications are not substantiated by strong and sound results. Nonetheless, conventional stress echocardiography for myocardial ischemia detection is heavily criticized on the basis of its subjectivity. Stress echocardiography has a long lasting history and the evidence collected over 20 years positioned it as an established tool for the detection and prognostication of coronary artery disease. The quantitative assessment of myocardial ischemia remains a scientific challenge and a clinical goal but time has not come for these newer ultrasonographic techniques which should be restricted to research laboratories.     

Effect of adalimumab on neutrophil function in patients with rheumatoid arthritis

Neutrophils are known to be targets for the biological activity of tumour necrosis factor (TNF)-α in the pathogenensis of rheumatoid arthritis (RA). Therefore, these cells may be among the targets of anti-TNF-α therapy. In this study we evaluated the effect of therapy with adalimumab (a fully human anti-TNF-α mAb; dosage: 40 mg subcutaneously every other week) on certain phenotypic and functional aspects of neutrophils obtained from 10 selected patients with RA and 20 healthy control individuals. Peripheral blood neutrophils were obtained at baseline and during anti-TNF-α therapy (2, 6 and 12 weeks after the first administration of adalimumab). All patients had been receiving a stable regimen of hydroxychloroquine, methotrexate and prednisone for at least 3 months before and during the study. Baseline neutrophil chemotaxis was significantly decreased in RA patients when compared with control individuals (P < 0.001). Two weeks after the first administration of adalimumab, chemotactic activity was completely restored, with no differences noted between patients and control individuals; these normal values were confirmed 6 and 12 weeks after the start of anti-TNF-α therapy. Phagocytic activity and CD11b membrane expression on neutrophils were similar between RA patients and control individuals; no modifications were observed during TNF-α neutralization. The production of reactive oxygen species, both in resting and PMA (phorbol 12-myristate 13-acetate)-stimulated cells, was significantly higher in RA patients at baseline (P < 0.05) and was unmodified by anti-TNF-α mAb. Finally, we showed that the activation antigen CD69, which was absent on control neutrophils, was significantly expressed on neutrophils from RA patients at baseline (P < 0.001, versus control individuals); however, the molecule was barely detectable on cells obtained from RA patients during adalimumab therapy. Because CD69 potentially plays a role in the pathogenesis of arthritis, our findings suggest that neutrophils are among the targets of anti-TNF-α activity in RA and may provide an insight into a new and interesting mechanism of action of anti-TNF-α mAbs in the control of inflammatory arthritis.     

Seasonal Variation in the Occurrence of Acute Urinary Retention

Objective: To determine whether acute urinary retention shows a seasonal variation. Methods: All acute urinary retentions observed in the emergency room of St. Anna Hospital, Ferrara, along an eight-year period (1991–1998) were considered. Diagnosis was made on the basis of history, physical examination, and bladder drainer by insertion of a catheter with registration of the retained urinary volume. The main determining cause of the acute urinary retention event was tentatively determined. Month and day of each event were categorized both by seasons and monthly intervals. For statistical analysis chi-square test for goodness of fit and partial Fourier series were used. Results: 1,133 acute urinary retention events were observed in 929 different subjects (871 males, 58 females). In 738 cases it was possible to define the main determining cause of the event. The seasonal distribution showed a higher frequency peak of events in summer and autumn both for total population and males subgroup. Analysis by determining cause of the event demonstrated a greater frequency of events in summer only in patients with prostatic hypertrophy. Chronobiologic evaluation showed a circannual pattern for acute urinary retention, both for total sample and male subgroup, with a significant peak in late summer (August–September). Analysis by main determining cause revealed a similar circannual pattern only for cases of acute urinary retention determined by prostatic hypertrophy. Conclusions: The present study shows that acute urinary retention exhibits a circannual distribution in its occurrence, particularly when caused by prostatic hypertrophy.     

An ab initio MO-LCAO investigation of the electronic structure of organic hydroperoxides and platinum(II) hydroperoxo complexes: A contribution to the knowledge of the mechanism of olefin epoxidation

A possible new process of activation of the OOH group in the mechanism of ethylene epoxidation catalysed by Pt(II) diphosphine complexes has been investigated by ab initio MO-LCAO calculations. The electronic and geometric features of YOOH species (Y = H, CH₃, t-But, CF₃, CH₃CO, (PH₃)₂Pt(CF₃), (PH₃)₃PtCl) have been evaluated and compared. Coordination of the OOH group to platinum induces an inversion of the polarity of the O-O bond when compared to any organic hydroperoxide; parallelly it favours the isomerisation of the OOH group from a hydroperoxo to an oxywater-like structure. This latter effect could be an important factor in favouring the reaction of the platinum coordinated OOH group with ethylene to form ethylene oxide. In fact, calculations on the energetics of the interaction between H₂O₂ and C₂H₄ have shown that isomerisation of HOOH to H₂OO oxywater structure is the rate determining step for the epoxidation process.     

Polysulfonated Fluoro‐oxyPBI Membranes for PEMFCs: An Efficient Strategy to Achieve Good Fuel Cell Performances with Low H3PO4 Doping Levels

Polybenzimidazoles (PBIs) are promising materials to replace Nafion as the electrolyte in polymer electrolyte membrane fuel cells (PEMFCs). The challenge with these materials is to achieve a good compromise between the H₃PO₄ doping level and membrane stability. This can be obtained by a proper monomer design, which can lead to better performing membrane electrode assemblies (MEAs), in terms of durability, acid leaching, and electrode safety. Here the easy and inexpensive synthesis of hexafluoropropylidene oxyPBI (F₆‐oxyPBI) and bisulfonated hexafluoropropylidene oxyPBI (F₆‐oxyPBI‐2SO₃H) is reported. The membranes based on F₆‐oxyPBI‐2SO₃H are more stable in an oxidative environment and more mechanically resistant than standard PBI and F₆‐oxyPBI. Whereas the attainable doping levels are low because of fluorine‐induced hydrophobicity, polysulfonation allows high proton conductivity, and fuel cell performances better than those reported for MEAs with F₆PBI‐ or PBI membranes with much higher doping levels. In the case of MEA with a F₆‐oxyPBI‐2SO₃H membrane, a peak power density of 360 mW cm^?2 is measured. Fuel cell performances of 604 mV at 0.2 A cm^?2 are maintained for 800 h without membrane degradation. Low H₂ permeability is measured, which remains almost unaffected during a 1000 h life‐test.     

Development and validation of the self-administered Fibromyalgia Assessment Status: a disease-specific composite measure for evaluating treatment effect

Introduction  

The Fibromyalgia Impact Questionnaire (FIQ) is a composite disease-specific measure validated for fibromyalgia (FM), but it is rarely used in clinical practice. The objective was to develop and analyse the psychometric properties of a new composite disease-specific index (Fibromyalgia Assessment Status, FAS), a simple self-administered index that combines a patient's assessment of fatigue, sleep disturbances and pain evaluated on the basis of the 16 non-articular sites listed on the Self-Assessment Pain Scale (SAPS) in a single measure (range 0 to 10).     

Protein flexibility in psychrophilic and mesophilic trypsins. Evidence of evolutionary conservation of protein dynamics in trypsin-like serine-proteases

To shed light on the molecular features related to cold-adaptation in serine-proteases, we have carried out molecular dynamics simulations of homologous mesophilic and psychrophilic trypsins, with particular attention to evaluation of intramolecular interactions and flexibility. Psychrophilic trypsins present fewer interdomain interactions and enhanced localized flexibility in regions close to the catalytic site. Notably, these regions fit well with the pattern of protein flexibility previously reported for psychrophilic elastases. Our results indicate that specific sites within the serine-protease fold can be considered hot spots of cold-adaptation and that psychrophilic trypsins and elastases have independently discovered similar molecular strategies to optimize flexibility at low temperatures.