[New developments in molecular genetics and treatment of retinoblastoma]. / Neue Entwicklungen zur Genetik und Therapie des Retinoblastoms.

Retinoblastomas are the most frequent primary malignant intraocular tumours worldwide. Conventional and new treatment modalities have significantly improved the chance for survival and preservation of vision. The armamentarium of treatment modalities has been broadened recently by new techniques like intraarterial chemotherapy, which still has to be considered as experimental since long-term follow-up results are not yet available. The excellent prognosis for retinoblastomas in countries with a well developed health system is contrasted by the miserable prognosis for retinoblastomas in developing countries, which must be changed by a joint effort of all centres.

[Severe aplastic anaemia in six children after non-A-E hepatitis without hepatic failure]. / Schwere aplastische Anämie bei 6 Kindern nach Non-A-E-Hepatitis ohne Leberversagen.

Aplastic anaemia can coincide with non-A-E hepatitis. Treatment follows a standardised study protocol of the German Society of Paediatric Oncology and Haematology (GPOH). Patients receive immunosuppression and/or bone marrow transplantation. We present six cases of aplastic anaemia after non-A-E hepatitis with different courses. In four of these children illness first presented with acute gastroenteritis. Five out of six children fully recovered, two of these with immunosuppression alone, three after bone marrow transplantation. One patient died due to complications of the bone marrow transplantation. In two patients steroid therapy was carried out to treat the hepatitis. This did not have any effect on the course of their aplastic anemia. We emphasise this common combination of aplastic anemia following non-A-E hepatitis. This overview underlines the necessity of regular blood testing after non-A-E hepatitis. Often gastroenteritis seems to precede illness thus perhaps indicating an infectious trigger.

The measurement of analyte diffusion from hydrogel microcapsules in model aqueous environments.

Model flavor analytes with varying partition coefficients were successfully encapsulated in approximately 150 microm diameter hydrogel microcapsules containing medium chain triglycerides (MCT). Analyte diffusion from the microcapsules into water and dextrose solutions was measured using a UV-VIS spectrophotometer fitted with a fiber optic probe. The diffusion of acetophenone, considered a hydrophilic analyte, was reduced as the dextrose concentration was increased in the water environment. Diffusion comparison was noted as t(1/2) which is the measure of time when 50% of the analyte concentration is released from the microcapsules. The measured t(1/2) for acetophenone in distilled water was 0.40 min. The addition of 20% dextrose to distilled water increased the t(1/2) to 0.60 min while the 40% dextrose addition extended the t(1/2) to 1.4 min. The same t(1/2) trends were also noted with methyl salicylate which is considered a hydrophobic analyte. The measured t(1/2) for methyl salicylate in distilled water was 2.0 min. The addition of 20% dextrose to distilled water increased the t(1/2) to 4.0 min while the 40% dextrose addition extended the t(1/2) to 9.0 min. The addition of dextrose to the water media effectively changes the partitioning media, increasing the resulting partition coefficient (Log P) values. Large changes in the Log P values were confirmed by the GC/FID analysis. In essence, water becomes a poor solvent for the analytes and diffusion is slowed from the hydrophobic MCT contained within the microcapsules as higher concentrations of dextrose is added to the water phase. Since methyl salicylate has a larger Log P(MCT: Water) value compared to acetophenone, the addition of dextrose extends the t(1/2) to a larger extent.

Piperacillin-tazobactam in pediatric cancer patients younger than 25 months: a retrospective multicenter survey.

Piperacillin-Tazobactam (Pip-Taz) is an evidence-based empirical treatment of febrile neutropenia in adolescents and adults. No data are available in pediatric cancer patients <25 months of age. In this retrospective, multicenter data survey, the analysis focuses on safety, tolerance, and efficacy. The daily dose administered was 240 mg/kg given in three equally divided doses. Data on 156 Pip-Taz treatment courses in 69 children <25 months from five pediatric cancer treatment centers (2001-2005) were analyzed. The median duration of treatment with Pip-Taz was 5 days (range, 1-23 days; 1-12 Pip-Taz courses per patient). Pip-Taz was started on the first day of fever in 90% of all courses, in 6% in the first 72 h, and in 4% as second- or third-line agent. Forty-five percent of all patients were neutropenic. In all patients, the outcome was favorable independent whether Pip-Taz was given as monotherapy (42 courses; 27%) or in combination. Overall, Pip-Taz was well tolerated and discontinued due to adverse events in only two patients who experienced non-life-threatening allergic reactions (skin rash and wheezing). The results of this study are preliminary due to the methodological limitations of a retrospective survey. Taking this bias into consideration, Pip-Taz appears to be a safe, and feasible alternative in pediatric cancer patients with febrile neutropenia <25 months of age suggesting that the inclusion of children of all age groups in future prospective controlled studies evaluating Pip-Taz is justified.

Malignant meningioma as a second malignancy after therapy for acute lymphatic leukemia without cranial radiation.

RATIONALE: Meningiomas in the pediatric age group are very rare tumors, comprising about 1-4.2% of all primary pediatric intracranial tumors. CASE REPORT: We present a 17-year-old patient who suffered from an intraventricular malignant meningioma. At the age of 2 years, acute lymphatic leukemia (common ALL [cALL]) was diagnosed and successfully treated with chemotherapy. There was no cranial radiation therapy. In December 2001, 13 years after diagnosis of cALL, he complained of headache, vomiting, and walking difficulties. Magnetic resonance imaging showed an enhancing mass with cystic components in the trigone of the right lateral ventricle. The tumor was removed completely. Histological diagnosis revealed a malignant papillary meningioma. After removal of a recurrent meningioma 16 months later, he received local radiotherapy. CONCLUSION: Pathogenetic mechanisms, treatment options, and prognosis of meningiomas and secondary malignancies of this age group are discussed.

[Retinoblastoma]. / Retinoblastom.

Retinoblastomas are the most frequent intraocular tumors in childhood. Untreated, the tumor is almost always fatal. Using a multidisciplinary approach combining the efforts of ophthalmologists, radiation oncologists, pediatric oncologists and geneticists a survival rate of more than 95% can be achieved. Molecular genetic research on the origin of retinoblastomas has substantially helped in our understanding of the origin of malignant tumors in general, as well as to the key role of the Rb-1 gene as a tumor suppressor.

Impact of surgery and adjuvant therapy on balance function in children and adolescents with cerebellar tumors.

OBJECTIVES: This study examined the effects of posterior fossa tumor surgery and concomitant irradiation and/or chemotherapy on the long-term recovery of balance function in children and adolescent patients. SUBJECTS AND METHODS: 22 patients, treated during childhood for a benign (n = 14) or malignant cerebellar tumor (n = 8), were examined in chronic state (mean latency between surgery and testing: 7.7 years, range 3 - 17 years). Postural impairments were assessed with static and dynamic posturography. All cerebellar lesions were documented by standardized and normalized MRI data. Healthy age- and gender-matched subjects served as a control group. RESULTS: Comparing the balance function of (i) children with or without affected cerebellar nuclei and (ii) children with and without adjuvant chemotherapy and/or radiotherapy revealed that damage to the cerebellar nuclei had more impact on neurological impairment than concomitant tumor therapy. Balance abnormalities were most pronounced when a lesion affected the fastigial nucleus. Chemotherapy with its neurological side effect was associated with enhanced postural sway in only two children with malignant tumors. CONCLUSIONS: The study results indicate that the sparing of the deep cerebellar nuclei had the greatest impact on the recovery of balance function in pediatric patients treated for both a benign or malignant cerebellar tumor.

Incidence of dysarthria in children with cerebellar tumors: a prospective study.

The present study investigated dysarthric symptoms in children with cerebellar tumors. Ten children with cerebellar tumors and 10 orthopedic control children were tested prior and one week after surgery. Clinical dysarthric symptoms were quantified in spontaneous speech. Syllable durations were analyzed in syllable repetition and sentence production tasks. Localization of the cerebellar lesions were defined after manual transfer from individual 2D-MR images onto 3D images of a spatially normalized healthy brain. Cerebellar children showed few and mild clinical signs of dysarthria. No difference was present in the sentence production task compared to controls. In five cerebellar children, syllables were prolonged in the syllable repetition task after surgery. Syllable duration normalized in an additional four-week session in all but one case. The MR-analysis showed that superior paravermal cerebellar areas likely involved in dysarthria in adults (paravermal lobules HVI, Crus I) were not significantly affected. In children, speech impairments appear to be rare after cerebellar surgery because tumors most commonly affect posterior-inferior and medial parts of the cerebellum while critical cerebellar regions are likely spared. The results suggest a similar localization of speech functions in the cerebellum in children and adults.

Do children with focal cerebellar lesions show deficits in shifting attention?

More recent findings suggest a possible role of the cerebellum in nonmotor functions. Disability of individuals with cerebellar damage in rapidly shifting attention is one frequently used example to support cerebellar involvement in mental skills. The original proposal was based on findings in five children with chronic surgical lesions of the cerebellum and a young adult with a degenerative disorder. The aim of the present study was to repeat Akshoomoff and Courchesne's initial findings in a larger group of children with focal cerebellar lesions. Ten children with cerebellar lesions and 10 age- and sex-matched controls were tested. Neocerebellar areas were affected in all children with cerebellar damage except one based on detailed analysis of MRI scans. Subjects had to perform a focus and a shift attention task. Two visual and two auditory stimuli were presented in a pseudorandom order. An ellipse and a high-pitched tone were presented less frequently than a circle and a low-pitched tone. Rare stimuli were presented at five different time intervals. In the focus tasks, subjects had to react to the same rare stimulus of one of the two modalities. In the shift task, subjects had to switch between the two rare stimuli. Motor deficits based on reaction times were small in cerebellar children compared with controls. The ability of target detection did not significantly differ in the children with cerebellar lesions compared with the control children in both the focus and the shift attention task. In particular, children with cerebellar damage showed no significant impairment in rapid (<2 s) shifts of attention. The present findings indicate that the cerebellum may be less critical in attention related processes than suggested previously.

Differential diagnosis of cholestasis following allogeneic hematopoietic stem cell transplantation in children: the contribution of serum bile acid levels in relation to other liver function tests.

Hepatic complications associated with cholestasis occur frequently in hematopoietic stem cell transplant recipients. Since bile acid seems to be a sensitive indicator of beginning cholestasis, the authors monitored total serum bile acid levels in addition to the standard liver function tests in 23 recipients of allogeneic transplants between June 1999 and September 2000. The observations suggest that bile acid is an early and sensitive marker of hepatic GvHD but not as specific as bilirubin. For cholestasis in absence of hepatic GvHD bile acid seems to be more sensitive than bilirubin. Routinely monitoring of bile acid after hematopoietic stem cell transplantation is not indicated.

High-dose chemotherapy with autologous stem cell rescue in children with retinoblastoma.

Children with metastatic retinoblastoma are considered to have a poor prognosis after conventional chemotherapy. We used high-dose chemotherapy (HDC) with peripheral hematopoietic stem cell transplantation in such patients in an attempt to improve their survival. Four patients with bone marrow metastases and one child with extraorbital disease were treated with HDC after achieving complete remission by enucleation and conventional chemotherapy. The child with extraorbital tumor was the only one to receive local irradiation. The conditioning regimen included thiotepa (900 mg/m(2)), etoposide (40 mg/kg) and carboplatin (1.5 g/m(2)) in four patients, and BCNU (300 mg/m(2)), cyclophosphamide (6.8 g/m(2)) and etoposide (1.6 g/m(2)) in one child. Hematologic recovery occurred without delay in all patients. The main toxicities were diarrhea, mucositis and infectious complications. No toxic deaths or any major late toxicities were observed. The child treated with the BCNU regimen developed a meningeal relapse 10 months after HDC, which was partially resected and treated with conventional chemotherapy, but not with radiotherapy. He is in complete remission (CR) 105 months off treatment. The other patients are in CCR for 107, 57, 9 and 8 months after HDC. HDC with thiotepa, etoposide and carboplatin may represent a curative option for children with extrabulbar or disseminated retinoblastoma responsive to chemotherapy. It may control occult CNS disease. The necessity to irradiate these children and the curative potential of this strategy for patients with bulky CNS disease remain to be determined.

Thermochemotherapy in hereditary retinoblastoma.

BACKGROUND/AIM: The combination of chemotherapy and transpupillary thermotherapy, thermochemotherapy (TCT) has become an established part of the treatment plan in advanced retinoblastoma. The aim of this study was to identify safe indications, the complications as well as the limitations of this new treatment for retinoblastoma. METHODS: Tumour response and side effects of TCT with an indirect laser ophthalmoscope (spot size about 400 micro m) in 55 tumours of 26 children with bilateral retinoblastoma were analysed. Using the Reese-Ellsworth classification system, nine of 35 eyes were classified as type I, 13 eyes as type II, 10 eyes as type III, and three eyes as type V. The mean age of the children was 0.74 (SD 0.61) years. The mean tumour height was 3.5 (2.3) mm with a mean diameter of 6.1 (4.1) mm. Treatment parameters were 4.3 (1.6) (median 5) thermochemotherapy sessions with a mean energy of 539 (211) mW and a mean duration of 13.5 (5.6) minutes. Chemotherapy courses (vincristine, etoposide, and carboplatin) were repeated every 3 weeks. The mean follow up period was 1.25 (0.6) years. RESULTS: Local recurrence occurred in 21 tumours (38%), with a mean onset of 3.2 (2.9) months after TCT. The risk of tumour recurrence was correlated with tumour height. The recurrence rate was 17% for tumours with a height less than 2 mm, 37% for tumours with a height between 2 and 4 mm, and 63% for larger retinoblastomas. Multivariate analysis identified fish flesh regression after TCT (p = 0.0007) as the most important risk factor for tumour recurrence besides tumour height (p = 0.001) and the necessity of increased laser power during TCT sessions (p = 0.018). Complications during therapy included transient corneal opacification in two eyes (6%), focal iris atrophy (three eyes, 8.5%), peripheral lens opacity (two eyes, 6%), circumscribed transient retinal detachment (one eye, 3%) and diffuse choroidal atrophy (one eye, 3%). CONCLUSION: TCT using an indirect laser ophthalmoscope with a spot size of about 400 micro m was efficient for retinoblastoma with a tumour height less than 4 mm. In larger tumours, the recurrence rate was unacceptably high. Fish flesh regression after TCT correlates with a higher rate of local tumour recurrence. Treatment related complications occurred in less than 9% of the treated eyes.

[Overweight and obesity in the Zurich canton. A LuftiBus study]. / Ubergewicht und Adipositas im Kanton Zürich. Eine LuftiBus Studie.

In this study the data from 30,598 subjects participating in the LuftiBus project during 1993-1998 were analyzed for the prevalence rates of overweight and obesity. 36.6% of men and 23.6% of the women in the total population were overweight (BMI 25.0-29.9 kg/m2) and 6.6% of the men as well as 7.5% of the women were obese (BMI > 30.0 kg/m2). At a younger age the women were in general lighter, however, with advancing age women became heavier than men. The prevalence data from this study are in quite good agreement with data from other Swiss epidemiologic studies as well international studies. The rather high prevalence rates of obesity show clearly that the problem of obesity can only be solved by preventive means.

White matter disease in children treated for malignant brain tumors.

OBJECTS: The objects of the study reported were to recognize different patterns of white matter disease (WMD) in the follow-up of children after surgery, radiation and/or chemotherapy for malignant primary brain tumors and to evaluate statistical data on the incidence of WMD and various risk factors. METHODS: Magnetic resonance imaging (MRI) records were evaluated retrospectively in the routine follow-up (range 6 months to 15 years after surgery) of 44 children with malignant primary brain tumors treated with surgery and radiotherapy and/or chemotherapy. RESULTS: WMD was diagnosed in 28 children and subclassified into circumscribed white matter lesions (WML) and diffuse atrophy. WML were the most common finding ( n=13), followed by atrophy ( n=7) and the combination of both ( n=8). Statistical analysis revealed slightly more frequent atrophy in children younger than 5 years. WML could be linked with supratentorial location of the tumor, follow-up longer than 5 years, and the presence of a ventricular shunt. Intrathecal chemotherapy was also a factor, but because of the small sample size of the group this might not be valid. None of the children had neurological deficits attributed to these findings, but the impact on neuropsychological development was not determined.

Proliferation-associated SNF2-like gene (PASG): a SNF2 family member altered in leukemia.

To identify genes involved in cell growth and/or apoptosis in leukemia, differential display was used to identify mRNAs that showed altered expression levels after cytokine withdrawal from the cytokine-dependent MO7e cell line. Sequence analysis of one transcript that showed a profound decrease in expression after cytokine withdrawal revealed it to be a member of the SNF2 family of chromatin remodeling ATPases. This cDNA had a 2514-nucleotide (838-amino acid) open reading frame and encoded an additional 230 amino acids at the NH2 terminus compared with the murine homologue, lsh, and the human counterpart, Hells. This gene locus has been designated SMARCA6 (SWI/SNF2-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 6). The highest levels of mRNA expression in humans are observed in proliferative tissues such as the thymus, testis, and bone marrow. Whereas cytokine withdrawal in MO7e cells leads to apoptosis and decreased mRNA expression, growth arrest without the induction of apoptosis of MO7e cells also leads to down-regulation of mRNA expression, suggesting an association with cell proliferation and not suppression of apoptosis. Nuclear localization of this SNF2-like putative helicase is dependent on a nuclear localization sequence located in the NH2-terminal region. Based on sequence homology to other SNF2-like helicases, the pattern of tissue expression, and the association of expression with cell proliferation, we refer to the protein product as proliferation-associated SNF2-like gene product [PASG (D. W. Lee et al., Blood, 94: 594a, 1999)]. Examination of acute myelogenous leukemia and acute lymphoblastic leukemia samples revealed a high frequency of a PASG transcript containing an in-frame 75-nucleotide deletion, which codes for a conserved motif known to be critical for the transactivation activity of a related yeast SWI/SNF polypeptide. These results extend our knowledge of this SNF2-like family member and suggest a role for PASG in leukemogenesis.

Rat antigen-induced arthritis: cartilage alterations assessed with iodine-123-antileukoproteinase.

UNLABELLED: Imaging of cartilage alterations was attempted in joints of rats with chronic antigen-induced arthritis (AIA) using the cationic 123I-labeled serine proteinase inhibitor antileukoproteinase (123I-ALP; pI > 10), which selectively accumulates in normal cartilage, presumably through interaction with negatively charged proteoglycans. METHODS: Iodine-123-ALP or 123I-myoglobin, a control protein of comparable size but with different isoelectric point (pI=7.3) was injected intravenously into normal or AIA rats. Joint accumulation was followed by scintigraphy for 14 hr. Tissue radioactivity was assessed by well-counter measurements after dissection. The content of charged molecules in articular cartilage was determined by toluidine blue staining; the degree of joint destruction was assessed in parallel by x-ray, ex vivo MRI and histopathology. RESULTS: In intact articular cartilage, ALP accumulated to a significantly higher degree than myoglobin. This preferential accumulation was lost in rats with chronic AIA. The target-to-background ratio for 123I-ALP negatively correlated with the loss of toluidine blue staining in cartilage, which documents depletion of charged matrix molecules (r=-0.92, p < 0.01 at 4 hr; r=-0.97, p < 0.01 at 13 hr). ALP scintigraphy was sensitive in detecting cartilage alterations, even though the degree of joint destruction and inflammatory infiltration was mild, as demonstrated by x-ray, MRI and histopathology. CONCLUSION: In rat AIA, loss of ALP accumulation appears to document proteoglycan depletion in mildly altered arthritic cartilage. ALP scintigraphy may represent a functional assay for early, premorphological cartilage alterations in human arthritis as well.