isrctn.org Identifier: ISRCTN54371254.

No abstract

Abstract. -We report new experimental results on granular compaction under consecutive vertical taps. The evolution of the mean volume fraction and of the mean potential energy of a granular packing presents a slow densification until a final steady-state, and is reminiscent to usual relaxation in glasses via a stretched exponential law. The intensity of the taps seems to rule the characteristic time of the relaxation according to an Arrhenius's type relation . Finally, the analysis of the vertical volume fraction profile reveals an almost homogeneous densification in the packing.Introduction. -Granular matter is a well known example of athermal systems; it means systems where classical thermodynamics do not apply since thermal energy (k B T ) is insignificant compared to the gravitational energy of a macroscopic grain. A static packing of grains is therefore in a metastable state, indefinitely trapped in a local minimum of the total potential energy. When submitted to an external perturbation, the system instantaneously acquires an extra mechanical energy and then relaxes to a new metastable configuration, which depends on the previous one as well as on the nature of the perturbation. This dependence can be investigated by implementing at regular intervals identical external excitations on an assembly of grains and analyzing the succession of static metastable states explored by the system. This is a common experiment in pharmaceutics when compacting powders but it is also a practical way to "thermalise" a granular media and to test the conceptual connection between granular compaction and the very slow relaxations of out-of-equilibrium thermal systems [1,2].The first experiments in this spirit have been carried out in Chicago [3,4,5]. Starting from a loose packing of beads confined in a tube, a succession of vertical taps of controlled acceleration induces a progressive and very slow compaction of the system. This evolution is well fitted by the inverse of the logarithm of the number of taps and, after more than 10,000 taps, a hypothetic steady state is still not reached. These results have motivated many theorical and numerical works, most of them dealing with the notion of free volume and geometric constraint [6,7,8]. Some of them underscore structural aging effects, as currently noticed in glasses.

This case-control study was designed to investigate the contributing factors for chronic masticatory myofascial pain (MFP). Eighty-three patients with MFP, selected from the dental clinics of the Jewish General and Montreal General Hospitals, Montreal, Canada, and 100 concurrent controls selected only at the first clinic, participated in this study. The association with MFP was evaluated for bruxism, head-neck trauma, psychological factors (symptom check list 90 revised questionnaire, SCL-90R) and sociodemographic characteristics by using unconditional logistic regression. Clenching-grinding was associated with chronic MFP in multiple models including anxiety (OR=8.48; 95% CI: 2.85; 25.25) and depression (OR=8.13; 95% CI: 2.76; 23.97). This association also remained for MFP, excluding all other temporomandibular disorders (TMD). Clenching-only (OR=2.54; 95% CI: 1.10; 5.87) and trauma (OR=2.10; 95% CI: 1.0; 4.50) were found to be associated with the chronic MFP, when the level of anxiety was adjusted in the model. No significant change was noted when the effects of clenching-only (2.76; 95% CI: 1.20; 6.35) and trauma (OR=2.08; 95% CI: 1.03; 4.40) were adjusted for depression. Clenching-only and clenching-grinding remained related to MFP regardless of patients being informed about these habits. A higher score of anxiety (OR=5.12; 95% CI: 1.36; 19.41) and depression (OR=3.51; 95% CI: 1.07; 11.54) were associated with MFP, as well as other psychological symptoms. In addition, female gender had almost three times the risk of chronic MFP than males when the model was also adjusted for psychological symptoms. Grinding-only, age, household income and education were not related with chronic MFP. Tooth clenching, trauma and female gender may contribute to MFP even when other psychological symptoms are similar between subjects.

Summary. Haematopoietic stem cell transplantation (HSCT) has been proposed for refractory autoimmune diseases, including systemic sclerosis (SSc). A sequential Bayesian phase I-II clinical trial was conducted in SSc patients to assess the feasibility, the tolerance and the efficacy of autologous HSCT. Peripheral blood stem cells (PBSC) were collected using cyclophosphamide (4 g/m 2 ) and recombinant human granulocyte colony-stimulating factor (5 lg/kg/d) and reinfused after positive CD34 + selection. Conditioning used cyclophosphamide (200 mg/kg) or melphalan (140 mg/m 2 ) according to cardiac function. The main end-point was the failure of the procedure, defined by failure of either PBSC mobilization, CD34 + selection or intensification procedure, or by procedure-related death. Among the 12 enrolled patients, three failures occurred: one PBSC mobilization, one CD34 + selection and one CD34 + intensification. Probability of graft failure was estimated at 0AE286 (95% confidence interval: 0AE095-0AE54). Autologous PBSC (n ¼ 10) or bone marrow (n ¼ 1) transplantation was actually performed in 11 patients with one procedurerelated death. Median time to neutrophil (> 0AE5 · 10 9 /l) and platelet (> 25 · 10 9 /l) haematopoietic reconstitution was 12 and 10 d respectively. After 18 months (range 1-26), eight out of 11 patients have shown major or partial response. Non-myeloablative conditioning, followed by a T cell-depleted autologous PBSC or bone marrow transplantation, appears feasible with low toxicity in severe SSc with short-term clinical benefits.