Patients receiving etoposide within four weeks after diagnosis had a good prognosis as five of the seven patients survived compared to one of 13 not treated with etoposide or treated late (chi-square test for survival, P = 0.0095). The Kaplan-Meier analysis showed the 2.5-year survival of 85.7 +/- 13.2% in the early etoposide-treated patients, compared to 10.3 +/- 9.4% in the remaining patients (log-rank test, P = 0.0141). Thus, early etoposide treatment is effective in treating EBV-HLH in young adults as well as in children.

No abstract

Activation-induced cytidine deaminase (AID) is required for somatic hypermutation (SHM) and class switch recombination (CSR) of the immunoglobulin (Ig) gene. AID has been reported to be specifically expressed in the germinal center (GC). Follicular lymphoma (FL) cells are known to be exposed to GC reaction, as characterized by a high degree of SHM with some heterogeneity in terms of intraclonal microheterogeneity and antigen selection. The heterogeneity of SHM pattern in FL intrigued us to investigate the AID expression. AID expression was investigated in 19 FL materials consisting of 15 cases of FL fresh cells and four cell lines. In all, 10 fresh cells and three cell lines expressed AID, but the others did not. SHM was investigated in 12 fresh cells and four cell lines. The ongoing mutation was significantly different between AID-positive and AID-negative FL fresh cells (unpaired Student's t-test, P ¼ 0.047). Ongoing mutation was not seen in any of the cell lines. AID expression was associated with the ongoing mutation in FL fresh cells (two-tailed Pearson's coefficient correlation, r ¼ 0.899, P ¼ 0.01). The switch off of AID expression may start in the B-lineage differentiation stage counterpart of FL after optimizing SHM, indicated by the cessation of the ongoing mutation in AID-negative FL fresh cells.

Appressoria of the phytopathogenic fungus Colletotrichum lagenarium contain melanin, which has been implicated as an important factor in the penetration of host plants. A cDNA clone containing the melanin biosynthetic gene encoding scytalone dehydratase (SCD1) from C. lagenarium was identified by hybridization with a heterologous cDNA probe from Magnaporthe grisea. The cDNA clone was used to identify a cosmid containing SCD1 in a genomic library of C. lagenarium, and the nucleotide sequence was determined for both the cDNA and genomic clones. The SCD1 gene contained one open reading frame composed of 188 codons and two deduced introns of 57 and 67 nucleotides. The deduced amino acid sequence of the N-terminal region of SCD1 showed high similarity to the amino acid sequence of scytalone dehydratase from Cochliobolus miyabeanus. A plasmid containing the SCD1 gene transformed the melanin-deficient mutant 9201Y (Scd ؊) to the wild phenotype but did not complement the conditional scytalone dehydratase-deficient mutant C. lagenarium 8015. Genomic DNA analysis indicated that the SCD1 gene is a single locus in C. lagenarium. Transcripts of the SCD1 gene were detected 2 h after the start of conidial germination.

We describe 2 elderly patients with Human herpesvirus 8 (HHV-8)/Kaposi sarcoma herpes virus negative malignant effusion lymphoma showing pan-B-cell immunophenotyping markers and successfully treated with a chimeric anti-CD20 IgG1 monoclonal antibody, rituximab. A 90-year-old man and an 87-year-old woman were hospitalized because of pleural effusions. They were diagnosed as having malignant effusion lymphoma on the basis of cytologic and flow cytometric findings of effusions, revealing involvement of atypical lymphoid cells and expression of CD19 and CD20. The former case was intolerant of chemotherapy because of toxicity. Using the conventional dose of rituximab, they showed neither intolerance nor adverse effects and their pleural effusions decreased immediately. Any sign of disease progression was not noted in either of the patients. They were negative for a HHV-8 infection and had no history of pyothorax. This type of lymphoma was not compatible with primary effusion lymphoma (PEL) defined by World Health Organization Classification of Tumors or pyothorax-associated lymphoma. We diagnosed these patients as having "HHV-8 negative malignant effusion lymphoma". HHV-8 negative malignant effusion lymphoma may be a new clinicopathologic and biologic entity. Because most of the cases were positive for pan-B-cell markers, rituximab may be a promising agent for the treatment.