IORT (intraoperative radiotherapy) in neuroblastoma: experience and first results.

Intraoperative radiotherapy (IORT) permits the application of a single large radiation dose to a malignant mass at the time of surgery sparing adjacent normal tissue from irradiation. Since 1996 we have used IORT to treat 13 children with neuroblastoma, stage 3 - 4. In all cases the tumour was not radically resectable at the first operation. Ultrasound, CT and MRI were performed and patients were treated with chemotherapy according to the NB90 protocol. The second-look operation was performed in the IORT operating room where the tumour was resected as completely as possible, while keeping the "no risk" principle in mind. Localised radiation of the residual tumour was 8 - 10 Gy. The child was monitored via 3 video cameras. No technical problems occurred during IORT application. The follow-up time was 6 - 69 months (May 2001). One patient died due to tumour progression, another in complete remission died after 9 months due to sepsis. The clinical course of 2 patients was complicated by a renal artery stenosis and a mesenteric artery occlusion. All other patients are in complete remission with regular follow-up examinations. Although the results are promising the number of patients is too small as yet for statistical analysis. However, IORT can be safely applied in patients with high-risk neuroblastomas, reducing the dose, side effects and resulting in remission.

p75 mediated apoptosis in neuroblastoma cells is inhibited by expression of TrkA.

BACKGROUND: Neurotrophins mediate their effects by binding to members of the Trk family of receptor tyrosine kinases and to the low-affinity nerve growth factor receptor p75. Nerve growth factor (NGF) has been demonstrated to support survival and differentiation of neuroblastoma (NB) cells by activation of the TrkA receptor. The p75 receptor belongs to the tumor necrosis factor (TNF) family of death receptors and has been suggested as a receptor that mediates apoptosis in neuronal and NB cells. PROCEDURE: To investigate the effect of p75 expression in NB, we transfected the p75 cDNA into SH-SY5Y cells, an NB cell line lacking expression of both p75 and TrkA. RESULTS: Cell clones expressing elevated levels of p75 showed a high degree of apoptosis even in 10% serum-supplemented medium. Apoptotic signaling by p75 was ligand-independent and only partly caspase-dependent. The level of apoptosis correlated directly with the expression level of the receptor, indicating that p75 may activate the cell death program directly. However, additional transfection of TrkA into SY5Y-p75 cells resulted in a significantly reduced rate of apoptosis even in the absence of NGF. CONCLUSIONS: Thus, expression of the TrkA receptor itself inhibits p75 mediated apoptosis in NB cells.

Occult thyroid pathology in a child with acquired immunodeficiency syndrome. Case report and review of the drug-related pathology in pediatric acquired immunodeficiency syndrome.

A 11-year-old boy with acquired immunodeficiency syndrome (AaS), Varicella-zoster virus (VZV) infection and long-term antiviral treatment suffered from a disorder of contractility of the left ventricle of the heart. Following severe unmanageable vomiting, the patient died and the postmortem examination showed marked involution of the lymphatic system, multiple foci of fibrosis of both ventricles of the heart, and regressive changes of the thyroid gland. Biochemical values of the thyroid gland function were, however, not altered. Neither human immunodeficiency virus-related p24 antigen, nor VZV DNA sequences were found in the thyroid gland. Regressive changes of the thyroid gland can probably occur before its function fails. By analyzing the possible etiologies, the endocrine toxicity of a long-term antiviral treatment should be taken into account.

Treatment of cerebral Langerhans cell histiocytosis.

Cerebral Langerhans cell histiocytosis (LCH) is a rare granulomatous disorder which may be primary or secondary or solitary or multiple. Brain structures outside the hypothalamic-pituitary axis are only scarcely involved, even in multisystem varieties. Since there are neither controlled therapeutic trials nor systematic analyses of hitherto reported cases, optimal treatment strategies are not known. To evaluate the effect of different treatment modalities, we analyzed previous reports of extrahypothalamic LCH back to 1980 in which the diagnosis was made on the basis of examination of cerebral tissues. Thirty-five histologically examined cases were identified, including 10 patients presenting with multiple cerebral lesions. Adding one own case followed up for 10 years, 16 patients had cerebral involvement secondary to multisystem LCH, while another 20 patients had primary cerebral LCH. The peak incidence was far beyond the pediatric range for both primary and secondary cerebral LCH. Localized lesions can be treated successfully by surgery or radiation following biopsy. Chemotherapy may be an additional option. Multiple lesions can tentatively be controlled by chemotherapy and, possibly, radiation. The ultimate outcome is determined by whether or not recurrencies or de-novo lesions will appear and the course of the systemic disease. Studies addressing the effects of therapy in cerebral LCH are urgently needed.

The CD95 (APO-1/Fas) system mediates drug-induced apoptosis in neuroblastoma cells.

Anticancer agents have been shown to trigger apoptosis in chemosensitive tumors such as neuroblastomas. We previously identified activation of the CD95 system as one of the key mechanisms for doxorubicin-induced apoptosis in leukemic T cells. Here, we report that therapeutic concentrations of doxorubicin, cisplatinum, and VP-16 led to induction of CD95 receptor and CD95 ligand (CD95-L) that mediated cell death in chemosensitive neuroblastoma cells. Using F(ab')2 anti-CD95 antibody fragments to interfere with CD95-L-receptor interaction markedly reduced apoptosis induced by those drugs in vitro. Cyclosporin A inhibited induction of CD95 mRNA and CD95-L mRNA and blocked drug-mediated apoptosis. Drug-induced apoptosis involved activation of caspases (interleukin 1beta-converting enzyme/Ced-3-like proteases) and processing of the prototype caspase substrate PARP and was completely blocked by benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone, a peptide inhibitor of caspases. In addition, neuroblastoma cells that were resistant to CD95-triggered apoptosis also displayed cross-resistance to chemotherapeutic agents. These data provide new clues for understanding the molecular requirements for drug-induced apoptosis in chemosensitive neuroblastoma cells by demonstrating that cell death was mediated via the CD95-L-receptor system and may open new avenues for targeting drug resistance of neuroblastoma.

[Response criteria for enzyme substitution in Gaucher disease]. / Response-Kriterien für die Enzymsubstitution bei Morbus Gaucher.

Recently the intravenous enzyme replacement therapy with modified beta-glucocerebrosidase has become available for patients with M. Gaucher. We report here the considerable improvement of activity and vigor in a 5 year old girl with type 1 M. Gaucher administering 60 IU/kg every two weeks for 6 months. The platelet count increased from 82-96/nl to more than 150/nl and hemoglobin from 10.8 to more than 12 g/dl. Serum acid phosphatase decreased from 14.6 U/l to 5.9. U/l and angiotensin-converting enzyme from 327 to 102 U/l. The estimation of splenic volume by MRT showed a decrease by 40%, while liver size was not reduced within 6 months of therapy. MRT proved to be useful to demonstrate the bone marrow infiltration by Gaucher cells. The enzyme replacement therapy resulted in an objective response. No side effects have been observed so far. The extreme high treatment costs enforce a considerable dose reduction for maintenance therapy.

Immunoscintigraphic imaging of mIBG-negative metastases in neuroblastoma.

We report a study of seven children with recurrent stage IV neuroblastoma comparing the uptake pattern of 123I-metaiodobenzylguanidine (mIBG) with 99mTc-labeled monoclonal antibody (MAb) BW 575 by the tumor lesions. Immunofluorescence studies of bone marrow had verified specific binding of the antibody to the tumor cells. The majority of tumor sites was detected both by mIBG and MAb scans. However, five of 26 lesions were not detected by mIBG and eight of 26 were false negative by immunoscintigraphy. The false negative lesions by mIBG belonged to five different patients (one of five primary, four of five bone marrow). In conclusion, MAb BW 575 may detect mIBG-negative neuroblastoma sites. The presence of antibody-negative sites suggests the utilization of both scintigraphy methods together.

[Pediatric neuroblastoma with early bilateral blindness]. / Kindliches Neuroblastom mit frühzeitiger beidseitiger Erblindung.

The authors present the case history of a child with neuroblastoma and early infiltration of the orbit accompanied by bilateral blindness. The typical clinical signs developed later. The thickening of the periosteum infiltrated by the tumor in the lateral wall of the orbit was demonstrated by computerized tomography. This may be regarded as an early sign of infiltration of the orbit by the neuroblastoma. In the case reported here a severe inflammatory reaction developed in the left orbit and anterior segment during massive chemotherapy and melted the cornea.

Expression of surface antigens during the cell cycle in different growth phases of American and African Burkitt's lymphoma cell lines.

We have studied the expression of five surface antigens in eight Burkitt's lymphoma cell lines during different phases of the cell cycle and in different growth phases (logarithmic and stationary). Cells were stained simultaneously for surface antigens (fluorescein coupled antibodies) and DNA content (propidium iodide), and dual parameter measurements were performed with a flow cytometer. Analysis of cells in specific cell cycle phases during log-phase growth revealed a 1.6-fold increase in surface antigen expression as cells passaged from G1 to G2/M. This is almost identical to the measured increase in cell surface area which occurs during passage of cells through the cell cycle and indicates that under optimal conditions surface antigen density is maintained during cell doubling. We also observed a consistent reduction, by about 50%, in the expression of surface IgM (mu), k-light chain, and B1 on the cell lines during a 5-day culture period. Cell lines that only weakly expressed surface IgM were found to have a more rapid decrease, and in such cell lines IgM was ultimately completely lost from the cell surface. In contrast, the expression of beta 2-microglobulin and HLA-ABC increased in some cell lines, whereas in others a significant decrease of both beta 2-microglobulin and HLA expression was demonstrated as the cells entered stationary growth phase. Decreased cell volume (and therefore surface area) associated with declining growth rate and fewer late S or G2/M cells could account for 20-30% of the observed reduction in surface IgM, k-light chain, and B1 expression, but the major decrement in fluorescence intensity was due to a reduction in the density of these surface antigens. Thus, the ability to maintain surface antigen densities is frequently lost in suboptimal culture conditions.

Burkitt's lymphoma in AIDS: cytogenetic study.

Cytogenetic studies were done in two cases of Burkitt's lymphoma in homosexual individuals with possible acquired immune deficiency syndrome (AIDS). The chromosomal abnormalities found are consistent with those previously described in the nonendemic form of Burkitt's lymphoma, with one of the two patients having the variant translocation, t(8;22). The production of the kappa light chain immunoglobulin by the tumor cells from the patient having t(8;22) and the occurrence of the different sites of translocation of the duplication of 1 q in the second patient are unusual findings. Whether there is an increase in the incidence of the variant translocation t(8;22) is yet to be determined.

Synthesis of kappa light chains by cell lines containing an 8;22 chromosomal translocation derived from a male homosexual with Burkitt's lymphoma.

Three cell lines were derived from a homosexual patient with probable acquired immunodeficiency syndrome and Burkitt's lymphoma. The cell lines produce an unusual strain of Epstein-Barr virus which will both transform cord blood lymphocytes and induce early antigens in Raji cells. Translocations between chromosomes 8 and 22 have occurred in all three lines, but the cells synthesize immunoglobulin M with light chains of the kappa type, in contrast to the usual concordance between a translocation involving chromosome 22 and lambda chain synthesis. Both kappa genes and one lambda gene are rearranged. These findings indicate either that translocation may occur as a separate event from immunoglobulin gene rearrangement or that the proposed hierarchical sequence of immunoglobulin gene rearrangements is not always adhered to. The data also imply that in cells containing a translocation between the long arm of chromosome 8 and a chromosome bearing an immunoglobulin gene, alteration of cellular myc expression may occur regardless of the immunoglobulin gene that is expressed.