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Human T-cell leukemia virus type I (HTLV I) does not cause leukemia in all persons who are infected. Indeed, the majority of infected individuals do not have any symptoms. However, a few infected persons, although asymptomatic, may be found upon examination to have an atypical T-lymphocytosis which may either spontaneously remit or may progress to an aggressive adult T-cell leukemia or lymphoma. The recent case of a 38-year-old black woman illustrates some of the features which may complicate the diagnosis of HTLV-related T-cell leukemia. The patient lived in French Guyana, an endemic region for HTLV I infection. She was initially found to have abnormalities of the lymph nodes of the neck and back, and biopsy revealed cells which on first examination appeared to be Hodgkin's lymphoma. The patient did not have antibodies to HTLV I. She was placed on chemotherapy, but the disease progressed and the patient died three months after diagnosis. During the chemotherapy for Hodgkin's disease, the patient developed antibodies against HTLV I, which prompted a reexamination of the biopsy material. With the help of hindsight, some convoluted cells were observed which were determined to be pleiomorphic T-cell lymphoma cells. Material extracted from the biopsy samples was shown to contain genomic DNA of the HTLV I, which made it clear that the virus was present from the outset and that the patient was already infected prior to the chemotherapy. The exact relationship between the appearance of HTLV I antibodies and the chemotherapeutic treatment is not clear, but two possibilities stand out. The immunosuppressive features of chemotherapy may have permitted the unopposed replication of some infected subsets of cells. Also possible is that the chemotherapy may have activated an infection with some cells which had been only latent up to that point. Other retroviruses, including the human immunodeficiency virus (HIV), may exist only as latent genes which are not expressed until activated by some chemical or biological event. (Consumer Summary produced by Reliance Medical Information, Inc.)

To define the junctional diversity of T-cell antigen receptor 5 gene rearrangements in fresh T-acute lymphoblastic cells and to correlate cell phenotype with the coding potential of rearrangements, we determined the junctional nucleotide sequences of 13 T-cell antigen receptor 5 gene rearrangements involving the preferentially rearranged V (Vδ1) and J (Jδ1) segments using in vitro gene amplification and direct sequencing. We showed that, as in 7δ+cell lines, extensive junctional diversity exists in these clones and that this diversity is due both to random nucleotide deletions/additions and to the use of at least two D5 segments. We also showed that a high percentage of these rearrangements are potentially translatable (7:13) and that such functional rearrangements occur in both surface CD3+and CD3−cells. Comparison of αβversus γδsurface expression demonstrates that all CD3+T acute lymphoblastic leukemias with a functional Vδ1-Jβ1 rearrangement express a surface γδreceptor and are recognized by the anti-j monoclonal antibody δTCS1, whereas a control CD3+γδ+leukemic case that had not undergone Vδ1rearrangement was δTCS1−. In addition, expression of this monoclonal antibody is not restricted by Vγ or Cγ usage or by the covalent or noncovalent link between γ and δchains.

A cDNA library from rat brain was constructed in pBR322 and screened with a 14-mer mixed oligonucleotide probe based on residues 231–235 of bovine proteolipid (PLP). A positive clone was isolated: it contained a 1334-base-pair cDNA insert and was subjected to DNA sequence analysis. The cDNA encoded information for the 276 amino acids of rat PLP. Comparison with bovine PLP sequence showed a complete amino acid sequence homology except for 4 amino acid residues.

Limited tryptic digestion of spectrin (Sp) from seven related individuals manifesting hereditary elliptocytosis (HE) or hereditary pyropoikilocytosis (HPP) phenotypes revealed the presence of a novel peptide with a molecular weight of 78 Kd and a concomitant decrease in the al domain (80-Kd peptide), which is the domain involved in the dimer self-association process. Sp from the normal members of this white family exhibited a normal peptide pattern, as compared with controls. The abnormal peptide pattern was associated with a decreased ability of Sp dimer to self-associate. In this kindred in which three generations were available for study, the clinical manifestations were quite variable and ranged from the asymptomatic HE carrier state to hemolytic HE or to severe anemia requiring splenectomy. The severity of the disease appeared to be correlated both with the amount of mutant spectrin (31 % to 69%) and with the excess of the Sp dimer found in the membrane (26% to 60%, compared with a normal value of 5.6% ± 2.2%). Partial amino acid sequencing showed that the αl/78-Kd peptide resulted from cleavage at lysine residue 10 of the αl/80-Kd domain. Knowledge of the exon/intron structure of cloned genomic DNA encoding the al domain allowed us to amplify in vitro a DNA fragment containing the third exon of the a-spectrin gene. The amplified fragment was subcloned and sequenced. A G to T transversion was found in the 39th codon (AGT for AGG), which changed the normal arginine to a serine. Hybridization of amplified DNAs with allele-specific oligo-nucleotides corresponding to the normal and mutant sequences confirmed the presence of the mutation in three other HE members of the family (the propositus mother, brother, and sister).