Microcomputed tomography evaluation of cement shrinkage under zirconia versus lithium disilicate veneers

Statement of problemComputer-aided design and computer-aided manufacturing (CAD-CAM) technology and the improved translucency of recently developed high-strength monolithic zirconia could make them clinically acceptable for veneers if bonding to zirconia was as predictable as to glass-ceramics. Few studies have compared how resin cements behave between glass-ceramic and zirconia veneers before and after polymerization.PurposeThe purpose of this in vitro study was to evaluate the volumetric polymerization shrinkage of resin cement, marginal discrepancy, and cement thickness before and after polymerization for glass-ceramic and zirconia veneers with light-polymerizing resin cement.Material and methodsTen lithium disilicate veneers and 10 zirconia veneers were fabricated with a CAD-CAM workflow on extracted human maxillary anterior teeth with intact enamel surfaces. Zirconia veneers were treated with airborne-particle abrasion, and lithium disilicate veneers were etched with 5% hydrofluoric acid. All specimens were treated with ceramic primer and cemented with a light-polymerized resin cement. All specimens were scanned before and after resin cement polymerization by microcomputed tomography. The data were processed by the Amira software program to compare polymerization volumetric shrinkage, cement thickness, and marginal discrepancy. The data were compared by using a t test and analysis of variance (α=.05). Two bonded veneers were loaded in a mastication simulator for 400 000 cycles to investigate the effect of cyclic fatigue loading.ResultsMean volumetric polymerization shrinkage was 4.2 ±0.8% for the lithium disilicate group and 6.4 ±3.5% for the zirconia group. No significant difference was found for volumetric shrinkage between materials (P=.132). The mean ±standard deviations of the marginal discrepancies before and after polymerization were 178 ±41 μm and 158 ±37 μm for lithium disilicate and 115 ±33 μm and 107 ±32 μm for zirconia. A smaller marginal discrepancy was found for both materials after polymerization (P=.011) and for zirconia compared with lithium disilicate (P=.004). The mean ±standard deviation cement thickness values before and after polymerization were 157 ±27 μm and 147 ±27 μm for lithium disilicate and 162 ±53 μm and 147 ±52 μm for zirconia. Smaller cement thickness was found after polymerization (P<.001), whereas no significant difference was found in cement thickness between materials (P=.144). No changes were noted in marginal discrepancy and cement thickness as a result of the fatigue loading.ConclusionsThe difference in the volumetric polymerization shrinkage of cement between lithium disilicate and zirconia veneers was not statistically significant. Polymerization shrinkage resulted in smaller marginal discrepancy and cement thickness for both veneer materials.     

Histerectomía periparto en el Hospital General Universitario de Elche

The aim of this study was to determine the incidence, indications, maternal outcomes and complications of peripartum hysterectomy in our environment. For this purpose we retrospectively analyzed 17 cases of peripartum hysterectomy performed at the Obstetrics and Gynecology Department of Hospital General Universitario de Elche between January 2001 and December 2005.     

Serum vascular endothelial growth factor receptor 3 as a potential biomarker in psoriasis

To discover novel biomarkers of psoriasis, a target‐specific antibody array screening of serum samples from psoriasis patients was initially performed. The results revealed that vascular endothelial growth factor receptor 3 (VEGFR‐3) was significantly elevated in the sera of psoriasis patients, compared to healthy controls. Next, ELISA validation studies in a larger cohort of psoriasis patients (N = 73) were conducted, which confirmed that serum VEGFR‐3 was indeed significantly increased in patients with psoriasis compared to healthy controls (P < 0.001). Furthermore, receiver operating characteristic curve analysis demonstrated that serum VEGFR‐3 exhibited potential in distinguishing healthy controls from psoriasis patients: area under the curve = 0.85, P < 0.001. In addition, serum levels of VEGFR‐3 were correlated with Psoriasis Area Severity Index scores (R = 0.32, P = 0.008) in psoriasis patients. Interestingly, serum VEGFR‐3 levels were significantly elevated in psoriatic arthritis compared to non‐psoriatic arthritis (P = 0.026). A pilot longitudinal study demonstrated that serum levels of VEGFR‐3 could reflect disease progression in psoriasis. Collectively, serum VEGFR‐3 may have a clinical value in monitoring disease activity of psoriasis.     

Effect of exotic mammalian predators on parasites of Cory's shearwater: ecological effect on population health and breeding success

Predator activity around the nests induces stress in breeding birds, which may have weaker immunity and are therefore more susceptible to parasite infections. The influence of predators on parasites has only been observed in land birds, and most studies are experimental. As seabird colonies offer excellent conditions for parasites, here we assess the influence of mouse, rat, and cat activity on parasites in Cory's shearwater (Calonectris diomedea borealis). Adults were examined for blood parasites and one adult and the juvenile from 53 nests were inspected for ectoparasites over two consecutive years (2010 and 2011). Nests differed in their physical characteristics and indices of mammal predator activity and were checked weekly to assess breeding success. Our results showed absence of blood parasites. Among the environmental factors, predator pressure received the most support (89 %) from the data as influencing nest ectoparasite intensity. Birds most infected had worse body condition, and breeding success was negatively influenced by predator activity and ectoparasite intensity. To our knowledge, this is the first analysis of the interaction between mammal predators and ectoparasites in seabird species and supports greater protection through eradication efforts. In addition, we provide the first data on the endoparasite fauna of Cory's shearwater.     

Histopathological evaluation of duodenal biopsy in the PreventCD project. An observational interobserver agreement study

Aim of the current study was to evaluate the inter‐observer agreement between pathologists in the diagnosis of celiac disease (CD), in the qualified context of a multicenter study. Biopsies from the “PreventCD” study, a multinational‐ prospective‐ randomized study in children with at least one‐first‐degree relative with CD and positive for HLA‐DQ2/HLA‐DQ8. Ninety‐eight biopsies were evaluated. Considering diagnostic samples with villous atrophy (VA), the agreement was satisfactory (κ = 0.84), but much less when assessing the severity of these lesions. The use of the recently proposed Corazza‐Villanacci classification showed a moderately higher level of agreement (κ = 0.39) than using the Marsh‐Oberhuber system (κ = 0.31). 57.1% of cases were considered correctly oriented. A number of >4 samples per patient was statistically associated to a better agreement; orientation did not impact on κ values. Agreement results in this study appear more satisfactory than in previous papers and this is justified by the involvement of centers with experience in CD diagnosis and by the well‐controlled setting. Despite this, the reproducibility was far from optimal with a poor agreement in grading the severity of VA. Our results stress the need of a minimum of four samples to be assessed by the pathologist.     

Metronomic treatment in immunocompetent preclinical GL261 glioblastoma: effects of cyclophosphamide and temozolomide

Glioblastoma (GBM) causes poor survival in patients even when applying aggressive treatment. Temozolomide (TMZ) is the standard chemotherapeutic choice for GBM treatment, but resistance always ensues. In previous years, efforts have focused on new therapeutic regimens with conventional drugs to activate immune responses that may enhance tumor regression and prevent regrowth, for example the “metronomic” approaches. In metronomic scheduling studies, cyclophosphamide (CPA) in GL261 GBM growing subcutaneously in C57BL/6 mice was shown not only to activate antitumor CD8⁺ T‐cell response, but also to induce long‐term specific T‐cell tumor memory. Accordingly, we have evaluated whether metronomic CPA or TMZ administration could increase survival in orthotopic GL261 in C57BL/6 mice, an immunocompetent model. Longitudinal in vivo studies with CPA (140 mg/kg) or TMZ (range 140–240 mg/kg) metronomic administration (every 6 days) were performed in tumor‐bearing mice. Tumor evolution was monitored at 7 T with MRI (T₂‐weighted, diffusion‐weighted imaging) and MRSI‐based nosological images of response to therapy. Obtained results demonstrated that both treatments resulted in increased survival (38.6 ± 21.0 days, n = 30) compared with control (19.4 ± 2.4 days, n = 18). Best results were obtained with 140 mg/kg TMZ (treated, 44.9 ± 29.0 days, n = 12, versus control, 19.3 ± 2.3 days, n = 12), achieving a longer survival rate than previous group work using three cycles of TMZ therapy at 60 mg/kg (33.9 ± 11.7 days, n = 38). Additional interesting findings were, first, clear edema appearance during chemotherapeutic treatment, second, the ability to apply the semi‐supervised source analysis previously developed in our group for non‐invasive TMZ therapy response monitoring to detect CPA‐induced response, and third, the necropsy findings in mice cured from GBM after high TMZ cumulative dosage (980–1400 mg/kg), which demonstrated lymphoma incidence. In summary, every 6 day administration schedule of TMZ or CPA improves survival in orthotopic GL261 GBM with respect to controls or non‐metronomic therapy, in partial agreement with previous work on subcutaneous GL261.