Assessment of the properties to characterize the interface between clay brick substrate and strengthening mortar

The behaviour of masonry elements under in-plane and out-of-plane loads can be improved through the application of strengthening systems based on reinforcing overlays. After strengthening, the transition region between the original substrate and the strengthening layer is especially stressed, and premature failure of the strengthened masonry is reached if insufficient interfacial capacity is assured. Therefore, the assessment of the mechanical behaviour of the interface is critical to the development of the masonry strengthening system based on the application of strengthening overlays. In this research a method for the characterization of the interface behaviour between two different materials, a polypropylene fibre reinforced mortar (PFRM) and a ceramic brick used for masonry construction is presented. Direct shear tests were carried out in couplet specimens. Due to the orthotropic nature of the bricks surface, the shear load was applied along three different directions in order to perform an overall estimation of the interface behaviour. The peak and residual shear stresses, as well as the failure modes, were obtained at different levels of the normal stress. Based on these experimental results constitutive laws were assessed for the simulation of the interface mechanical behaviour based on the Mohr and Mohr-Coulomb failure criteria.This research was carried in the framework of InoTec, Innovative material of ultra-high ductility for the rehabilitation of the built patrimony, funded by COMPETE/QREN/FEDER (NORTE-07-0202-FEDER-023024). InoTec project is promoted by CiviTest company and University of Minho. S&P Clever Reinforcement Ibérica is gratefully acknowledged for providing the materials used in the strengthening of the masonry specimen

Prognostic study of continuous variables (white blood cell count, peripheral blast cell count, haemoglobin level, platelet count and age) in childhood acute lymphoblastic leukaemia. Analysis of a population of 1545 children treated by the French Acute Lymphoblastic Leukaemia Group (FRALLE)

Many cutpoints have been proposed to categorize continuous variables in childhood acute lymphoblastic leukaemia (white blood cell count, peripheral blast cell count, haemoglobin level, platelet count and age), and have been used to define therapeutic subgroups. This variation in the choice of cutpoints leads to a bias called the ‘Will Rogers phenomenon’. The aim of this study was to analyse variations in the relative risk of relapse or death as a function of continuous prognostic variables in childhood ALL and to discuss the choice of cutpoints. We studied a population of 1545 children with ALL enrolled in three consecutive protocols named FRALLE 83, FRALLE 87 and FRALLE 89. We estimated the risk of relapse or death associated with different values of each continuous prognostic variable by dividing the sample into quintiles of the distribution of the variables. As regards age, a category of children under 1 year of age was distinguished and the rest of the population was divided into quintiles. The floated variance method was used to calculate the confidence interval of each relative risk, including the reference category. The relation between the quantitative prognostic factors and the risk was monotonic for each variable, except for age. For the white blood cell count (WBC), the relation is log linear. The risk associated with WBC values in the upper quintile was 1.9 times higher than that in the lower quintile. The peripheral blast cell count correlated strongly with WBC (correlation coefficient: 0.99). The risk increased with the haemoglobin level, and the risk in the upper quintile was 1.3 times higher than that in the lower quintile. The risk decreased as the platelet count increased: the risk in the lower quintile was 1.2 times higher than that in the upper quintile. The risk increased gradually with increasing age above one year. The small subgroup of patients (2.5% of the population) under 1 year of age at diagnosis had a risk 2.6 times higher than the reference category of patients between 3 and 4.3 years of age. When the risk associated with a quantitative prognostic factor varies monotonously, the selection of a cutpoint is arbitrary and represents a loss of information. Despite this loss of information, such arbitrary categorization may be necessary to define therapeutic stratification. In that case, consensus cutpoints must be defined if one wants to avoid the Will Rogers phenomenon. The cutpoints proposed by the Rome workshop and the NCI are arbitrary, but may represent an acceptable convention. © 2000 Cancer Research Campaign http://www.bjcancer.co

Comparison of Human Memory CD8 T Cell Responses to Adenoviral Early and Late Proteins in Peripheral Blood and Lymphoid Tissue

Treatment of invasive adenovirus (Ad) disease in hematopoietic stem cell transplant (SCT) recipients with capsid protein hexon-specific donor T cells is under investigation. We propose that cytotoxic T cells (CTLs) targeted to the late protein hexon may be inefficient in vivo because the early Ad protein E3-19K downregulates HLA class I antigens in infected cells. In this study, CD8+ T cells targeted to highly conserved HLA A2-restricted epitopes from the early regulatory protein DNA polymerase (P-977) and late protein hexon (H-892) were compared in peripheral blood (PB) and tonsils of naturally infected adults. In tonsils, epitope-specific pentamers detected a significantly higher frequency of P-977+CD8+ T cells compared to H-892+CD8+ T cells; this trend was reversed in PB. Tonsil epitope-specific CD8+ T cells expressed IFN-γ and IL-2 but not perforin or TNF-α, whereas PB T cells were positive for IFN-γ, TNF-α, and perforin. Tonsil epitope-specific T cells expressed lymphoid homing marker CCR7 and exhibited lower levels of the activation marker CD25 but higher proliferative potential than PB T cells. Finally, in parallel with the kinetics of mRNA expression, P-977-specific CTLs lysed targets as early as 8 hrs post infection. In contrast, H-892-specific CTLs did not kill unless infected fibroblasts were pretreated with IFN-γ to up regulate HLA class I antigens, and cytotoxicity was delayed until 16–24 hours. These data show that, in contrast to hexon CTLs, central memory type DNA polymerase CTLs dominate the lymphoid compartment and kill fibroblasts earlier after infection without requiring exogenous IFN-γ. Thus, use of CTLs targeted to both early and late Ad proteins may improve the efficacy of immunotherapy for life-threatening Ad disease in SCT recipients

No improvement of survival with reduced- versus high-intensity conditioning for allogeneic stem cell transplants in Ewing tumor patients

Background: Outcomes of Ewing tumor (ET) patients treated with allogeneic stem cell transplantation (allo-SCT) were compared regarding the use of reduced-intensity conditioning (RIC) and high-intensity conditioning (HIC) regimens as well as human leukocyte antigen (HLA)-matched and HLA-mismatched grafts. Patients and methods: We retrospectively analyzed data of 87 ET patients from the European Group for Blood and Marrow Transplantation, Pediatric Registry for Stem Cell Transplantations, Asia Pacific Blood and Marrow Transplantation and MetaEICESS registries treated with allo-SCT. Fifty patients received RIC (group A) and 37 patients received HIC (group B). Twenty-four patients received HLA-mismatched grafts and 63 received HLA-matched grafts. Results: Median overall survival was 7.9 months [±1.24, 95% confidence interval (CI) 5.44-10.31] for group A and 4.4 months (±1.06, 95% CI 2.29-6.43) for group B patients (P = 1.3). Death of complications (DOC) occurred in 4 of 50 (0.08) and death of disease (DOD) in 33 of 50 (0.66) group A and in 16 of 37 (0.43) and 17 of 37 (0.46) group B patients, respectively. DOC incidence was decreased (P < 0.01) and DOD/relapse increased (P < 0.01) in group A compared with group B. HLA mismatch was not generally associated with graft-versus-Ewing tumor effect (GvETE). Conclusions: There was no improvement of survival with RIC compared with HIC due to increased DOD/relapse incidence after RIC despite less DOC incidence. This implicates general absence of a clinically relevant GvETE with current protocol