A prospective epidemiological study was carried out in the West Nile District of Uganda from 1972 to 1979 in order to investigate the aetiological role of the Epstein-Barr virus (EBV) in Burkitt's lymphoma (BL). By 1976, fourteen BL cases had been detected among the 42,000 children originally bled in the study area. Testing of sera from BL candidates and neighbourhood controls showed that children who develop BL later have EBV/VCA titres several dilutions higher than their age- and sex-matched neighbours. This appearance of a strong EBV activity long before BL development was taken as evidence of a causal role of EBV in BL. In order to add to the unique material of pre-bled BL cases, BL detection was continued up to March 1979 when field work became impossible in Uganda. Two additional pre-bled BL cases were found during this extension of the study. The serological and virological evaluation of these additional cases showed that the EBV/VCA titres, but not the EA and EBNA titres, were about two dilutions higher in the BL candidates than in the controls. Hybridization assays showed that both lymphomas contained EBV/DNA in the tumour cells. These additional results thus confirm the findings in the first 14 cases and strengthen the epidemiological evidence for a causal role of the EBV in endemic BL.

In a retrospective analysis of 87 cases of Caucasian childhood non-Hodgkin malignant lymphoma (NHML) from Lyon, France, all the case were diffuse lymphomas, but 47 were diagnosed as monomorphic small non-cleaved NHML, pathologically indistinguishable from Burkitt's lymphoma (BL). BL could then be the most frequent childhood lymphoma in France. This homogeneous series allows better definition of the characteristics of BL within NHML. Age distribution is similar to that of endemic BL, with a sex ratio of 3.7/1. Abdominal masses are initially present in 68% of the cases, whereas jaw is involved in only 4%. The disease is characterized by its overwhelming evolution in the absence of therapy. However, complete remission (CR) is usually obtained after the first chemtherapy regimen. Most relapses occur at 3-8 months. Death could be related to cerebrospinal fluid (CSF) involvement, local recurrence or secondary marrow involvement. Ninety per cent of the patients alive with no evidence of disease (NED) 8 months after CR can be considered as definitely cured. Our study on Caucasian children with NHML indicates that, from histological and clinical criteria, nearly half the cases are very similar to African BL. Even though EBV rarely associated with our cases, BL could be a worldwide lymphoma.

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Neurofibromatosis 2 (NF2) is a dominantly inherited disorder characterized by multiple tumors of the central nervous system, predominantly bilateral vestibular schwannomas. The gene for NF2 is located in the chromosomal region 22q12 between the loci D22S1 and D22S28. We have performed genetic linkage analysis on 13 NF2 families with a total of nine polymorphic DNA markers, including five which we have recently mapped to this region. Two loci, D22S32 and NEFH, are linked to the NF2 locus at 0% recombination (lod scores of 6.03 and 4.28, respectively). By multipoint linkage analysis, we assign the NF2 gene to an interval of 7 cM, between the loci D22S212 and D22S28. We have used this set of nine markers to construct chromosome 22 haplotypes for the 82 at-risk individuals in this pedigree set. It has been possible to determine, with a high degree of certainty, the carrier status of 70 (85%) of these at-risk individuals. Risk prediction was possible in every case where DNA was available from both parents. Fifty-three of the 70 (76%) informative individuals were assigned decreased risks of being carriers. The use of chromosome 22 probes for risk assessment should result in a greatly reduced number of individuals who require periodic screening for NF2.

The existence of two closely related calcitonin (CT)/CT gene-related peptide (CGRP) genes has been recognized in rat and man. In man, expression of the CALC-I gene produces CT and/or CGRP-I mRNA, whereas CGRP-II mRNA is transcribed from the CALC-II gene. Until recently, expression of the CALC-II gene had been detected only in a metastasis of medullary thyroid carcinoma. In this study, expression of the CALC-II gene was demonstrated by Northern blot hybridization analysis in four of six cell lines established from different Ewing sarcomas, a malignant neoplasm of bone. Expression of the CALC-I gene was not detected in any of the six cell lines. A presumed large mol wt immunoreactive precursor of CGRP-II and small amounts of mature CGRP-II, but no CT, were found in medium from IARC/EW 1 cells. Nucleotide sequence analysis of cloned cDNA from this cell line confirmed the production of CGRP-II mRNA. CALC-II gene expression in Ewing sarcoma might be useful for studies concerning regulation of gene expression in the CALC gene family and possibly for tumor classification.