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Abstract A case of severe diarrhoea associated with synergistic human bocavirus type 1 (HBoV) and human herpes virus type 6 (HHV6) is reported. The case supports the hypotheses that HBoV infection under clinical conditions may depend on helper viruses, or that HBoV replicates by a mechanism that is atypical for parvoviruses, or that HBoV infection can be specifically treated with cidofovir.

Osteonecrosis (ON) is a debilitating side effect of anti-leukemic treatment. Thus far, the role of leukemic infiltration (LI) of bone is unclear. The first 30 children aged ≥10 years, who were enrolled in the ongoing OPAL trial and had MRI studies at diagnosis and at 6 months, were analyzed. MRI revealed extensive LIs in 24 (80%) patients. The signal abnormalities changed back to a physiological signal in 29 out of 30 children at 6 months. Of the 24 children with LIs at diagnosis, 3 (12.5%) developed ON ≥ II, whereas 4 (66.7%) patients without LIs subsequently developed ON ≥ II (p = .016). No differences between children initially presenting with/without LIs were observed concerning age, pubertal stage, white blood count, immunophenotype, and clinical presentation. Initial radiological LI of bone and, thus, single MRI at diagnosis cannot identify children at high risk of developing radiological ON at 6 months into treatment. [ABSTRACT FROM PUBLISHER]

Purpose: MRI alone has its limitations for target selection in biopsy or resection in newly diagnosed and pretreated pediatric brain tumor patients. F-FET-PET imaging is considered to identify metabolically active tumor tissue and to differentiate it from therapy-associated changes. We retrospectively analyzed our experience with F-FET-PET in targeted surgical interventions for pediatric brain tumors. Methods: In 26 cases with lesions suspicious of a growing brain tumor on MRI, either newly diagnosed or after antitumoral treatment led to F-FET-PET imaging for target selection prior to stereotactic biopsy, navigated open biopsy or navigated microsurgical tumor resection. Indications for F-FET-PET imaging were visualization of metabolic active tumor tissue within diffuse tumors or pretreated lesions as well as depicting their extent. Results: F-FET-PET integration in surgery was feasible in all patients using stereotaxy or neuronavigation. Sensitivity for tumor detection was 20/24. F-FET-PET was false positive in two pretreated patients. Conclusion: F-FET-PET imaging is helpful for target selection and can be integrated in surgical guidance. F-FET-PET image-guided surgical targeting yielded histological diagnosis with decent specificity and high sensitivity in our cohort of pediatric brain tumor patients. Our results warrant further evaluation of F-FET-PET imaging for surgical guidance. [ABSTRACT FROM AUTHOR]

A case of severe diarrhoea associated with synergistic human bocavirus type 1 (HBoV) and human herpes virus type 6 (HHV6) is reported. The case supports the hypotheses that HBoV infection under clinical conditions may depend on helper viruses, or that HBoV replicates by a mechanism that is atypical for parvoviruses, or that HBoV infection can be specifically treated with cidofovir.

Second central nervous system (CNS) relapses represent about 7.3% of subsequent recurrences of childhood acute lymphoblastic leukemia (ALL). In most children these subsequent CNS relapses occur during the first 18 months after diagnosis of the first relapse (mean 1.42 +/- 0.73 years). We present a patient who suffered a second ALL relapse in the CNS more than seven years after diagnosis of his first relapse. The leukemic clone was completely stable over more than ten years as shown by minimal residual disease techniques. Possible reasons for the recurrence of the leukemic clone after this very long period of dormancy (e.g. role of the disease site, immune system dysfunction) are discussed.

Background and Objectives: Immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements are excellent patient-specific targets for polymerase chain reaction (PCR)-based detection of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL). Nevertheless, instability of these targets during the course of the disease has important implications for PCR-based MRD monitoring and may lead to false negative results., Design and Methods: Several studies have shown that Ig and TCR targets are reasonably stable in ALL between diagnosis and first relapse, but up to now, there are no data on the stability of these targets between first and second relapse. We, therefore, performed a PCR-study on bone marrow samples from 49 children with precursor B-ALL at first and second relapse. Homo-heteroduplex PCR analyses were used for identification of clonal IGH, IGK-Kde, TCRG and TCRD gene rearrangements. Clonal targets were studied by sequencing and/or comparative homo-heteroduplex analysis., Results: In 52% (25/48) of the patients, all PCR targets identified at first relapse were preserved at second relapse; in 92% (44/48) of the patients at least one target and in 73% (35/48) at least two targets remained stable. Best stability was found for IGH and TCRG gene rearrangements., Interpretation and Conclusions: Based on these first data about clonal stability of Ig and TCR targets between first and second relapse of childhood precursor B-ALL, we developed a stepwise strategy for appropriate selection of stable PCR targets for MRD monitoring. This strategy was applicable in 84% of the relapsed patients and resulted in at least one stable MRD-PCR target per patient in 98% of these children.