Minimal clinically important difference of the 6-min walking test in patients with asthma.

BACKGROUND: The 6-min walking test (6MWT) is responsive to physiological changes and pulmonary rehabilitation (PR) in patients with asthma. The minimal clinically important difference (MCID) has not been established yet.OBJECTIVE: To determine the MCID of 6MWT in patients with asthma.METHODS: Using the perceived change in walking ability and the modified Medical Research Council (mMRC) score as anchors, receiver operating characteristic curves and quantile regression, we evaluated 6MWT before and after PR in these patients. The St George Respiratory Questionnaire (SGRQ), the COPD assessment test (CAT) and other outcome measures were also assessed.RESULTS: Of 142 patients with asthma, 37 were enrolled. After PR, 6MWT increased from 453.4 m ± 88.8 to 493.0 m ± 97.2 (P = 0.0001); other outcome measures also increased. There was a slight correlation between baseline 6MWT and SGRQ, CAT and mMRC. No significant correlations were found between post-PR changes in 6MWT and in other outcome measures. Comparing different methods of assessment, the MCID ranged from 26 m to 27 m.CONCLUSION: The most conservative estimate of the MCID of 6MWT after PR was 26 m in patients with asthma. This estimate may be useful in clinical interpretation of data, particularly in response to intervention studies.

Role of a conserved glycine triplet in the NSS amino acid transporter KAAT1.

K+-coupled amino acid transporter 1 (KAAT1) belongs to the NSS family of solute transporters and it is expressed in the midgut and in salivary glands of Manduca sexta larvae. As more than 80% of family members, KAATI shows a stretch of three glycines (G85-G87) that according to the structure of the prototype transporter LeuT, is located close to the access of the permeation pathway. In this work the role of the triplet has been investigated by alanine and cysteine scanning methods in protein heterologously expressed in Xenopus laevis oocytes. All the mutants were functional but the surface expression level was reduced for G85A and G87A mutants and unaffected for G86A mutant. All presented altered amino acid uptake and transport associated currents in the presence of each of the cations (Na+, K+, Li+) that can be exploited by the wt. G87A mutant induced increased uncoupled fluxes in the presence of all the cations. Cross-linking studies, performed by the treatment of cysteine mutants with the oxidative complex Cu(Il)(l,10-phenanthroline)3, showed that limiting the flexibility of the region by covalent blockage of position 87, causes a significant reduction of amino acid uptake. Na+ protected G87C mutant from oxidation, both directly and indirectly. The conserved glycine triplet in KAAT1 plays therefore a complex role that allows initial steps of cation interaction with the transporter.

The treatment of stable and unstable proximal femoral fractures with a new trochanteric nail: results of a multicentre study with the Veronail.

The incidence of hip fractures continues to rise. This study is the first evaluation of a new intramedullary implant, the Veronail, that provides double axis fixation into the femoral head and allows the surgeon to choose whether to use sliding or fixed locked proximal screw fixation for trochanteric femoral fractures. The fractures were classified according to the AO classification, and function was assessed with the Modified Harris Hip Score. 111 patients with trochanteric fractures were evaluated in eight Italian hospitals. The stable 31.A1 fractures were treated with sliding proximal screws, the subtrochanteric 31.A3 fractures with converging proximal screws, and the unstable 31.A2 fractures were treated with both types of proximal fixation. The unstable fractures treated with locked converging screws had the same function at one year as those treated with sliding screws. This study suggests a possible new method of treating unstable trochanteric femoral fractures. This may be the solution to prevent excessive collapse of the fracture with the resultant poor function and persisting pain noted in the literature. Two converging locked proximal screws seem to provide stable fixation in 31.A2 femoral fractures and produce as good a result as the use of traditional sliding screws. The role of converging locked proximal screws in unstable trochanteric fractures requires further evaluation.