Diffuse large B-cell lymphoma in pediatric patients belongs predominantly to the germinal-center type B-cell lymphomas: a clinicopathologic analysis of cases included in the German BFM (Berlin-Frankfurt-Munster) Multicenter Trial

Diffuse large B-cell lymphoma (DLBCL) in adults is a heterogeneous disease. Biologic subgroups of DLBCL with a favorable prognosis (germinal center B-cell-like, GCB) and with a poor prognosis (activated B-cell-like, ABC) have been defined by gene expression profiling and can be distinguished by immunohistochemistry. In contrast to their adult counterparts, children with DLBCL have an excellent prognosis. We analyzed 63 cases of DLBCL in pediatric patients by immunohistochemistry and fluorescence in situ hybridization (FISH) and found a striking predominance of a GCB subtype, which might explain the good clinical outcome in these lymphomas. Interestingly, FISH applied to 50 of these cases, as well as conventional cytogenetics available in 3 cases, revealed absence of the translocation t(14;18) involving the BCL2 gene, which is present in about 15% of adult GCB subtype DLBCL. Our data indicate that pediatric DLBCL differs from adult DLBCL and might comprise a biologically unique subgroup of DLBCL from which important insights into the pathogenesis and biology of this disease might be gained.     

Scanning electron microscope comparative surface evaluation of glazed-lithium disilicate ceramics under different irradiation settings of Nd:YAG and Er:YAG lasers

Objective:To evaluate the surface of glazed lithium disilicate dental ceramics after irradiation under different irradiation settings of Nd:YAG and Er:YAG lasers using a scanning electron microscope (SEM).Materials and Methods:Three glazed-press lithium disilicate ceramic discs were treated with HF, Er:YAG, and Nd:YAG, respectively. The laser-setting variables tested were laser mode, repetition rate (Hz), power (W), time of exposure (seconds), and laser energy (mJ). Sixteen different variable settings were tested for each laser type, and all the samples were analyzed by SEM at 500× and 1000× magnification.Results:Surface analysis of the HF-treated sample showed a typical surface texture with a homogenously rough pattern and exposed ceramic crystals. Er:YAG showed no effect on the surface under any irradiation setting. The surface of Nd:YAG-irradiated samples showed cracking, melting, and resolidifying of the ceramic glaze. These changes became more pronounced as the power increased. At the highest power setting (2.25 W), craters on the surface with large areas of melted or resolidified glaze surrounded by globules were visible. However, there was little to no exposure of ceramic crystals or visible regular surface roughening.Conclusions:Neither Er:YAG nor Nd:YAG dental lasers exhibited adequate surface modification for bonding of orthodontic brackets on glazed lithium disilicate ceramics compared with the control treated with 9.5% HF.     

Evaluation of specific anaerobic power in 12–14-year-old male rowers

No previous study had applied the modified Wingate rowing test to young athletes (i.e. children and adolescents). The aims of this study were to evaluate the trial-to-trial reliability of a rowing-modified Wingate test in a group of 12–14-year-old rowers (n = 98) and to compare anaerobic power values among the 12-, 13-, and 14-year-old rowers after accounting for differences in physical maturity and body size. Each subject performed two “all-out” 30-s trials on a Concept II rowing ergometer. The trials were separated by a 15-min active recovery period, which included walking and stretching and ensured the participants’ full recovery. The test proved to be highly reliable, with coefficients of variations of 2.4 and 2.9% (CI = 2.1–3.4%) and intraclass correlation coefficients of 0.994 and 0.996 (CI = 0.991–0.997) for mean power and peak power, respectively. The ANCOVA analyses accounting for differences in body size and level of physical maturity (assessed using indices of pubic hair) and the Bonferroni post hoc tests identified the 14-year-olds as having significantly greater adjusted mean power and peak power values (P < 0.01) than the other two age groups, while the differences between the 12- and 13-year-olds in terms of mean power and peak power were not significant. Our findings indicate (1) that the rowing-modified Wingate test may be reliably used for the assessment of specific anaerobic performance in 12–14-year-old rowers and (2) that factors other than physical maturity and body size are partly responsible for the increase in anaerobic power during growth.     

Laxative abuse complicating bulimia: Medical and treatment implications

Literature concerning laxative abuse among young women with bulimia is reviewed. Laxative abuse appears to be much more common among females with bulimia than among females who do not meet criteria for bulimia. Patients with bulimia most commonly abuse stimulant-type laxatives. The abuse of laxatives is associated with potentially serious sequellae involving the gastrointestinal tract as well as generalized systemic effects. The different types of laxatives, their mechanisms of action, and the medical complications of laxative abuse are reviewed. Recommendations regarding laxative withdrawal are offered.