Foot and ankle kinematics in rheumatoid arthritis: influence of foot and ankle joint and leg tendon pathologies

Objective From early onset of the disease, patients with rheumatoid arthritis (RA) experience walking impairments. Pathologic effects of RA on foot and ankle structures have been studied clinically, but little is known as to how they relate to kinematic changes during gait. The aim of this study was to explore the relationship between clinically observed pathologies of foot and ankle joints and leg tendons and the corresponding gait kinematics. Methods The gait of 25 subjects with varying stages of RA was recorded and foot and ankle kinematics were assessed. Magnetic resonance imaging was performed for each subject: first metatarsophalangeal (MTP) joint, midfoot, and hindfoot synovitis, erosion scores, and leg tendon involvement were determined. The joint alignment and motion score represented daily clinical assessment. The 95% confidence intervals of the Spearman's correlation coefficient tests were used to explore the relationships between the clinical and kinematic parameters. Results Maximum first MTP joint dorsiflexion at preswing was related to reduced first MTP joint passive motion, first MTP joint synovitis and erosion, midfoot synovitis and erosion, and hindfoot erosion. Midfoot pronation range of motion during single stance was related to subtalar alignment and Achilles tendon involvement. Hindfoot eversion range of motion during single stance was related to subtalar alignment and peroneus longus tendon involvement. Involvement of the tibialis posterior tendon could not be identified as an independent factor influencing foot or ankle kinematics. Conclusion Our findings suggest moderate to strong relationships between foot and ankle gait kinematics and structural pathologies

Can we assess baseline pain and global health retrospectively?

OBJECTIVE: To study the agreement between patients' actual baseline assessments of pain and global health before treatment and retrospective assessments collected 2 weeks after treatment.\ud \ud METHODS: Data were collected in a prospective study of 200 rheumatology outpatients treated with a local corticosteroid injection. At baseline and 2-week follow-up, localized pain and global health were assessed on 100 mm visual analogue scales. The follow-up questionnaire was extended with a retrospective assessment of pain and global health before treatment.\ud \ud RESULTS: At follow-up patients slightly overestimated the severity of pain and global health before treatment. Actual and retrospective assessments were adequately correlated (pain: r(r(r(s) = 0.73; global health: r(s) = 0.67). Bland-Altman analysis showed that both pain and global health were characterized by high intra-individual variation between actual and retrospective assessments, with the 95% limits of agreement (-37.3 to 32.3 mm for pain and -49.7 to 37.8 mm for global health) far exceeding proposed values for minimal clinically important differences.\ud \ud CONCLUSION: Over a 2-week interval, patients' retrospective assessments of baseline pain and global health are fairly accurate and adequately correlated with actual baseline scores. At the group level, retrospective assessments can provide acceptable data on baseline pain and global health. The wide variability between actual and retrospective assessments, however, indicates that even over short time intervals there is poor individual agreement between the two methods

Coping with somatic illnesses in online support groups: Do the feared disadvantages actually occur?

People in stressful circumstances, such as serious health conditions, often turn to support groups. With the increase in the availability and popularity of the Internet, the possibility has arisen to join support groups online. Various authors have raised potential disadvantages of these groups, such as the lack of control of the quality of the information that is exchanged and the concern that the exchange within the group might include socially inappropriate remarks. In this study we explored to what extent these potential disadvantages actually occur. In addition, we explored who uses Dutch online support groups and what is exchanged by the participants. By means of “content analysis” we analyzed a random sample of 1500 messages from publicly available online support groups for patients with breast cancer, arthritis and fibromyalgia. It appeared that the online support groups under study were mainly used by female patients. A major part of the postings contained “off topic” remarks. Popular health related topics were “restrictions in daily life” and “regular medication”. Only in a minor proportion of the postings, potential disadvantages were present. Therefore this study suggests that online support groups are a viable option for support

Set obres sobre retòrica i persuasió

El comentari crític de set obres sobre retòrica i persuasió, publicades recentment, ofereix una visió de diverses perspectives teòriques i també de les aplicacions a situacions comunicatives específiques. Les obres són El arte de hablar , de José Antonio Hernández Guerrero i María del Carmen García Tejera; Retórica , de Giambattista Vico, editada per primera vegada en castellà; 40 jocs per parlar català , de Jacqueline Jacquet, Sílvia Casulleras, Núria Mirabet; Acròbates de l'emoció , d'Amadeu Viana; Tres finestres obertes al món de la comunicació , de Ricard Morant i Miquel Peñarroya; El lenguaje de la negociación , de Joan Mulholland; i Tècniques de negociació i resolució de conflictes , de Carles Mendieta i Suñé

Patient-perceived satisfactory improvement (PPSI): interpreting meaningful change in pain from the patient's perspective

The assessment of clinically meaningful changes in patient-reported pain has become increasingly important when interpreting results of clinical studies. However, proposed response criteria, such as the minimal clinically important difference, do not correspond with the growing need for information on truly meaningful, individual improvements. The aim of the present study was to investigate satisfactory improvements in pain from the patient’s perspective. Data were collected in a 2-week prospective study of 181 arthritis patients treated with a local corticosteroid injection. Baseline and follow-up pain were assessed on 100 mm visual analogue scales for pain intensity (VAS-PI). At baseline, patients also marked a hypothetical level on a VAS-PI representing a satisfactory improvement in pain. Patient-perceived satisfactory improvement (PPSI) was constructed using a 5-point categorical rating of change scale at follow-up as the anchor. PPSI was associated with a minimal reduction of 30 mm or 55% on the VAS-PI. Since absolute change in pain associated with satisfactory improvement proved highly dependent on baseline pain, percent change scores performed better in classifying improved patients. The 55% threshold for satisfactory improvement was consistent over the course of treatment and reasonably consistent across groups of patients. Our data suggest that PPSI is a clinically relevant and stable concept for interpreting truly meaningful improvements in pain from the individual perspective

Optimisation of an ejector in a CO2 refrigerant cycle

L’objectif de cette étude est d’optimiser un cycle frigorifique au CO2 pour une application dans le transport frigorifique. Les performances de l’unité doivent être supérieures à celles d’une machine avec une injection de vapeur et un compresseur bi-étagé déjà commercialisé. Suite à l’étude de plusieurs solutions, un éjecteur couplé à un échangeur interne semble la solution la plus intéressante.Un banc expérimental est créé à partir de l’unité possédant une injection de vapeur. L’éjecteur est muni d’une aiguille pour pouvoir assurer une recherche de la haute pression optimale. L’échangeur interne est équipé d’un by-pass pour modifier la puissance échangée. Un ensemble de points d’essais est testé avec deux températures d’évaporation : 0 °C et -20 °C, et trois températures de source chaude : 30 °C, 38 °C et 50 °C.L’éjecteur avec aiguille est capable de s’adapter à différentes températures extérieures en modifiant la haute pression. L’échangeur interne permet d’augmenter les performances du cycle mais présente une limite, la température au compresseur devient élevée et présente un risque de détérioration de ses performances ou de l’huile.Avec le cycle présentant un éjecteur, une amélioration du coefficient de performance est observée pour les points avec une température d’évaporation de 0 °C mais celle-ci chute drastiquement pour les températures d’évaporation de -20 °C. Une analyse exergétique du cycle confirme les faibles performances de celui-ci pour des températures d’évaporation négatives.À partir des résultats expérimentaux, des modèles numériques sont mis en place. Les échangeurs, vannes de détente sont modélisés de manière conventionnelle. Pour le compresseur, le modèle de Winandy est modifié afin de fonctionner pour un compresseur bi-étagé avec injection de vapeur. L’éjecteur est modélisé à travers un modèle unidimensionnel basé sur des transformations simplifiées décrites à travers des rendements isentropiques. Tous les modèles sont validés mais ceux des échangeurs ont un temps de calcul CPU trop important pour pouvoir être utilisés sur une modélisation dynamique.The aim of this study is to optimize a CO2 cooling cycle for transport application. The efficiency of the unit needs to be superior that of a cycle with vapor injection and a two stages compressor. The solution proposed is to install an ejector with an internal heat exchanger.A test bench is created from a pre-existing unit. Tests are made for two evaporation temperatures: 0 °C and -20 °C and three external temperatures: 30 °C, 38 °C and 50 °C. The ejector is equipped with a needle to seek the optimal high pressure. The internal exchanger is equipped with a by-pass to modify the thermal power exchanged.The ejector with needle can change the high pressure to seek the optimal conditions. The internal heat exchanger increases the efficiency of the cycle but the rising of temperature at the compressor can degrade its efficiencies or the oil. The new cycle increases the COP for evaporation temperature of 0 °C but the COP is lower than without ejector for evaporation temperature of -20 °C. An exergetic analysis shows that indeed the cycle is less efficient for low evaporation temperature.From the experimental results, numerical models are created to realize a system simulation and to test different scenarii to drive the unit. Exchangers and valves modeled with conventional tools. Wynandy’s model is adapted to be used on a two-stage compressor with vapor injection. The ejector is modeled with a one-dimensional model, based on simplified transformations described with isentropic efficiencies. All models seem to work but the CPU time is too high to use the exchanger models for dynamic simulation