Cytotoxic activity of rev protein of human immunodeficiency virus type 1 by nucleolar dysfunction

The rev protein (Rev) of the human immunodeficiency virus type 1 (HIV-1) is known as a post-transcriptional regulator of viral gene expression. It is located in the cell nucleolus. Transiently expressed Rev caused nucleolar ballooning and deformity with aberrant accumulation of rRNAs, and de novo synthesis of rRNAs decreased dramatically in these cells. However, similarly expressed rex protein (Rex) of the human T-cell leukemia virus type I, which is a functional homologue to Rev, did not affect nucleolar structure and function. Rev expression resulted in cell death with nucleolar destruction in an inducible cell line. Analysis of Rev mutants revealed that both the nucleolar targeting signal of Rev and the multimerization domain are prerequisites to the nucleolar disintegration by Rev. Human T-cells acutely infected with HIV-1 contained nucleoli which were deformed and filled with Rev, but chronically infected cells had intact nucleoli. Involvement of Rev in cytopathic effects in HIV-1 infection is discussed.

Overgrowth of human synovial cells driven by the human T cell leukemia virus type I tax gene

One of the salient pathological features of rheumatoid arthritis is synovial cell proliferation with bone erosion. Despite extensive investigation, the factors essential for synovial cell proliferation remain to be identified. Recent studies suggest that human T cell leukemia virus type I (HTLV-I) may play an important role in synovial overgrowth observed in patients with one type of chronic inflammatory synovitis. In order to confirm and extend these observations, we have established synovial cell clones (SCCs) from three HTLV-I carriers who demonstrated synovial overgrowth but were otherwise asymptomatic. HTLV-I proviral DNA randomly integrated into the cellular genome was present in 20-30% of SCCs. The SCCs carrying HTLV-I proviral DNA and expressing the tax gene exhibited high levels of proliferative potential. HTLV-I was found to function as a transcriptional trans-activator in these SCCs. Moreover, transfection of the tax expression plasmid into SCCs resulted in the same phenotype of increased proliferation and cytokine expression as exhibited by HTLV-I provirus-carrying and tax-expressing SCCs. These data suggest that tax plays a critical role not only in leukemogenesis but also in synovial overgrowth in humans.

Molecular diversity of calpastatin in human erythroid cells

According to differences in mobility on SDS-polyacrylamide gel electrophoresis, calpastatins (inhibitor proteins of the calcium-dependent proteinase calpain) are classified into the tissue type (100-120 kDa) and the erythrocyte type (70 kDa), which lacks the amino-terminal domains (domains L and 1). We investigated the molecular diversity of calpastatin in human hematopoietic cells by Western-blot analysis and by the reverse-transcription-polymerase-chain reaction method. While the mononuclear and polymorphonuclear cells in peripheral blood showed the tissue type (110 and 114 kDa), a cell line of erythroid cells (JK-1) showed both the tissue type (110 kDa) and the erythrocyte type (70 kDa) at approximately equal ratios. When the lysate of JK-1 cells was incubated in the presence of ATP, the 110-kDa form was degraded much faster than the 70-kDa form. In human erythrocytes, the 110-kDa form was identified as the tissue type by an antibody recognizing domain L, and this form was also present in addition to the predominant 70-kDA form. JK-1 cells, as well as nucleated cells in peripheral blood, contained calpastatin mRNA with exon-3-deleted. Glioblastoma and fibroblast cell lines expressed the nondeleted calpastatin mRNA in addition to the deletion type, and they showed bands corresponding to 117 kDa as well as 110 and 114 kDa. The 117-kDa band was detectable by an anti-exon 3 peptide antibody. These results suggest that diversity among the tissue type calpastatins is caused by both alternative splicing and post-translational processing whereas the apparent conversion from the tissue type to the erythrocyte type is caused by proteolytic processing.

Characterization of a novel biphenotypic leukemia cell line, TA-1, with myeloperoxidase and inducible cytoplasmic mu chain: altered rearrangement patterns of antigen receptor genes

A novel biphenotypic cell line carrying t(9;11)(p22;q23), TA-1, was established from the peripheral blood of a patient with acute undifferentiated leukemia. The TA-1 cells simultaneously expressed lymphoid (CD19, CD20) and myeloid characteristics (CD13, CD33, myeloperoxidase) on the same cells. When the cells were treated with tetraphorbol acetate, cytoplasmic mu chain was induced and the fluorescence intensity of CD13 was increased. These findings suggested that TA-1 cells have a bidirectional maturation capacity, as well as biphenotypic features. Molecular analysis disclosed differences in the rearranged bands, corresponding to one allele of the immunoglobulin heavy chain gene (IgH) and the T cell antigen receptor gamma gene (TCR gamma), between the non-cultured cells and the cell line, while showing identical rearranged patterns of another allele of both these genes and the TCR beta gene. These results suggest that the non-cultured cells and the established cell line have the same clonal origin and that the latter is a clonal descendant of the former.

Effects of physical exercise on the elasticity and elastic components of the rat aorta

To evaluate the effects of exercise on aortic wall elasticity and elastic components, young male rats underwent various exercise regimes for 16 weeks. In the exercised rats, the aortic incremental elastic modulus decreased significantly when under physiological strain. The aortic content of elastin increased significantly and the calcium content of elastin decreased significantly in the exercised group. The accumulated data from the exercised and sedentary groups revealed that the elastin calcium content was related positively to the incremental elastic modulus. We concluded that physical exercise from an early age decreases the calcium deposit in aortic wall elastin and that this effect probably produced in the exercised rats a distensible aorta.

Phosphorylation of the Rex protein of human T-cell leukemia virus type I

Rex protein, the posttranscriptional regulator of human T-cell leukemia virus type I (HTLV-I), is required for the control of viral structural protein expression and virus replication. Rex is a phosphoprotein found predominantly in the cell nucleolus, whose function is thought to be regulated by its nucleolar localization and phosphorylation. Therefore, we investigated the in vivo phosphorylation of Rex protein in more detail. Phosphorylation of Rex occurred in all HTLV-I-infected cell lines examined in vivo, primarily at serine residues and to a very small extent at threonine residues. Treatment of cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) led to significant but transient enhancement of the incorporation of [32P]orthophosphate into Rex protein. N-terminal truncation of Rex protein abolished TPA-dependent phosphorylation. Chymotryptic digestion of phosphorylated Rex yielded two phosphopeptides. In vivo phosphorylation sites were identified as serine residues 70 and 177 and threonine residue 174. Serine 70 was a TPA-dependent phosphorylation site within a regulatory domain. We have already shown that the protein kinase C inhibitor H-7 (1-(5-isoquinolinylsulfonyl)-2-methylpiperazine) specifically blocked accumulation of viral unspliced gag-pol mRNA. Therefore, the phosphorylation at serine 70 may be involved in the regulation of Rex function in response to extracellular stimuli.

Transforming activity and the level of Tax protein: effect of one point mutation in HTLV-I tax gene

The transcriptional trans-activator molecule of HTLV-I, Tax, is known to transform rodent fibroblasts. A revertant clone expressing Tax was obtained by treating transformed Rat-I cells harboring a single copy of the tax gene with a mutagen. Sequence analysis of the tax gene of the revertant clone revealed that it had one point mutation at codon 12(CTT----TTT), resulting in a change from Leu to Phe. The colony-forming efficiencies of the cells transfected with the mutant tax gene (mu71 tax) were significantly lower than those transfected with the wild-type by the soft-agar method. This difference was shown to be due to the instability of mu71 Tax.

Maturational stage specific immunoglobulin heavy chain gene rearrangements, determined by D and D upstream region gene structures

In 43 cases of various B-cell lineage tumors, precise gene structures of rearranged immunoglobulin heavy chain (IgH) were studied. By Southern-blot analysis of D upstream (5'D) gene of IgH, biallelic rearrangement structures, D-J or V-D-J, were determined and consequently maturational stage specific IgH rearrangement patterns were investigated. B-precursor ALL cases (especially stage IV of Nadler's criteria) have V-D-J rearranged IgH genes on both alleles. In contrast, most of the mature B-cell malignancies, excluding multiple myeloma, have IgH genotype of D-J/V-D-J. In addition, in case of D-J/V-D-J, the D gene used in D-J joining has been speculated by Southern-blot of D genes. So, these approaches for inquiring precise structures of rearranged IgH genes are supposed to provide new information of lymphocyte differentiation and leukemogenesis.

Intranuclear topological distribution of HIV-1 trans-activators

Subcellular localization of human immunodeficiency virus type I (HIV-1) Tat and Rev was examined using a confocal laser scanning microscope (CLSM). In transfected COS-7 cells, Tat resided exclusively in the perinocleolar region, while Rev infiltrated fully into the nucleoli. The chimeric Tat in which the nucleolar targeting signal was replaced by that of Rev, which retains trans-acting activity of Tat, remained still in the perinucleolar region as wild-type Tat. Perinucleolar distribution of Tat protein suggests the existence of a novel nucleolar architecture that affects transcription.

Multiple carcinoid tumors of the stomach with hypergastrinemia

A 42-yr-old woman presented with multiple carcinoid tumors in her stomach and a markedly elevated serum gastrin level. Total gastrectomy was performed, and 22 small carcinoid tumors were found in the gastric fundus and body. A high serum gastrin level was revealed in the gastric drainage veins; still more gastrin was detected in the carcinoid tumors by the immunohistochemical method, and many secretory granules were found in the tumor cells with an electron microscope. The fundic gland showed marked atrophy, and there was some conglobation of endocrine cells (ECL cells). This case suggests a hypothetic sequence of anacidity due to atrophic gastritis----hypergastrinemia----proliferation of ECL cells----multiple carcinoids. A search of the Japanese literature revealed that 26 cases of multiple carcinoid tumors in the stomach have been reported so far, and most of them support this hypothesis.

Rearrangement patterns of immunoglobulin heavy chain (IgH) and light chain genes in acute lymphoblastic leukemia and chronic myelocytic leukemia lymphoid crisis cells showing oligoclonal IgH gene rearrangements

We investigated leukemic cells with multiple immunoglobulin heavy chain (IgH) gene rearrangements from nine B-precursor cell acute lymphoblastic leukemia (ALL) patients and three chronic myelocytic leukemia lymphoid crisis (CML.Ly-BC) patients in order to determine detailed recombination patterns of the variable (V), diversity (D), and joining (J) region genes. Southern blot study, using DNA probes for DQ52 and 5'D region genes, was useful to distinguish VDJ recombination from DJ recombination at the level of each allele. Leukemic cells from seven out of eight CD10-positive ALL patients showed biallelic VDJ recombinations. Rearrangements of Ig kappa genes were found in only one case. Leukemic cells from all of the CML.Ly-BC patients had a DJ/(V)DJ IgH genotype. These findings suggest that the multiple IgH gene rearrangements in B-precursor cell ALL occurred as a consequence of continuing V-(V)DJ rearrangements after neoplastic transformation, and were closely related to the stage of bone marrow B-precursor cell differentiation. Multiple IgH gene rearrangements in CML.Ly-BC might take place earlier in the process of IgH gene rearrangements than is the case in B-precursor cell ALL. In this sense, the genotypic oligoclonality observed in ALL and CML.Ly-BC should be regarded not as 'true', but as 'pseudo' oligoclonal leukemia.

Functional conversion from HIV-1 Rev to HTLV-1 Rex by mutation

A nucleolar localizing rev gene mutant M10 of human immunodeficiency virus type 1 (HIV-1) lost a Rev function completely, instead, gained a Rex activity of human T cell leukemia virus type 1 (HTLV-1). The obtained compatibility between Rev M10 and Rex with their own nucleolar targeting signal (NOS) suggests a common molecular mechanism of their post-transcriptional regulation, despite no sequence similarities of both proteins and their responsive RNA elements, respectively.

Induction of c-fos and c-myc mRNA expression by immunoglobulin G from patients with Graves' disease in thyrotrophin-dependent rat thyroid cell line (FRTL5)

The present study was conducted to evaluate effects of autoantibodies in patients with Graves' disease on induction of c-fos and c-myc mRNA expression in rat thyroid cell line (FRTL5). IgG fractions were isolated from 11 patients with Graves' disease, and six healthy subjects, with protein A-Sepharose. FRTL5 cells which had been grown to subconfluency and deprived of TSH for a week were exposed to the IgG for an hour. Expression of c-fos and c-myc mRNAs was examined by the Northern blot method using nick-translated v-fos and c-myc probes. C-fos and c-myc transcripts were induced by IgGs from two patients with Graves' disease, which displayed much higher activities in assays for TSH binding inhibitor immunoglobulins, thyroid stimulating antibodies and thyroid growth-stimulating immunoglobulins, assessed by measuring inhibition of 125I-TSH binding to the TSH-receptor, cAMP production and 3H-thymidine incorporation in FRTL5 cells, respectively, compared with those in the remaining patients. The induction of c-fos and c-myc mRNAs by IgG from a patient with Graves' disease was suppressed by preincubation with IgGs from two patients with primary myxoedema who were known to have a blocking type TSH-receptor antibody. These data suggest that the binding of the antibodies to the TSH-receptor followed by cAMP production is related to the induction of c-fos and c-myc mRNAs and, thus, to the growth of FRTL5 cells. To our knowledge, this is the first report demonstrating that autoantibodies induce proto-oncogene mRNA expression.

Effects of chimeric mutants of human immunodeficiency virus type 1 Rev and human T-cell leukemia virus type I Rex on nucleolar targeting signals

Two chimeric mutant genes derived from rev of human immunodeficiency virus type 1 and rex of human T-cell leukemia virus type I were constructed to investigate the functions of the nucleolar-targeting signals (NOS) in Rev and Rex proteins. A chimeric Rex protein whose NOS region was substituted with the NOS of Rev was located predominantly in the cell nucleolus and functioned like the wild-type protein in the Rex assay system. However, a chimeric Rev with the NOS of Rex abolished Rev function despite its nucleolar localization. This nonfunctional nucleolar-targeting chimeric protein inhibited the function of both Rex and Rev. In the same experimental conditions, this mutant interfered with the localization of the functional Rex in the nucleolus.

The nucleolar localisation signal of the HTLV-I protein p27rex is important for stabilisation of IL-2 receptor alpha subunit mRNA by p27rex

In this study we investigated the mechanism of stabilisation of IL-2 receptor alpha subunit mRNA by the HTLV-I protein p27rex. We tested the role of the nucleolar targetting signal in rex by introducing mutations. Three deletion mutants could not express rex protein in the nucleolus and although protein was still expressed in the nucleoplasm none of the mutants could stabilise IL-2R alpha mRNA. A substitution mutant could be expressed in the nucleolus and could also stabilise IL-2R alpha mRNA. The data show that the nucleolar targetting signal is crucial for stabilisation of IL-2R alpha mRNA by rex and raise the possibility that transport of mRNA from nucleus to cytoplasm can involve the nucleolus.

HTLV-1 p27rex stabilizes human interleukin-2 receptor alpha chain mRNA

Expression of the pX gene products (p40tax, p27rex and p21X-III) of human T cell leukemia virus type 1 (HTLV-1), which is known to be a causative agent of adult T cell lymphoma/leukemia, induces expression of the interleukin-2 receptor alpha chain (IL-2R alpha) on infected T cells. Comparison of IL-2R alpha promoter activities has revealed that the transcriptional activation of the promoter alone cannot explain the large numbers of IL-2R alpha expressed on HTLV-1 infected cells. We found that the rates of the IL-2R alpha mRNA degradation were greatly reduced in pX-positive cells as compared with pX-negative cells. Simultaneous transfection of the expression vector plasmid containing IL-2R alpha cDNA and similar plasmids containing various pX sequences showed that p27rex elongated the half life of IL-2R alpha mRNA. As p27rex did not affect the transport of the IL-2R alpha mRNA from nucleus to cytoplasm, prolongation of the IL-2R alpha mRNA half life by p27rex is ascribed to stabilization of the mRNA. Experiments using deletion mutants and chimeric constructs of the IL-2R alpha cDNA demonstrated that the coding sequence but not the 5' or 3' untranslated region of the IL-2R alpha mRNA sequence is responsible for its protection by p27rex.

Protein kinase inhibitor H-7 blocks accumulation of unspliced mRNA of human T-cell leukemia virus type I (HTLV-I)

Rex, the post-transcriptional regulator of human T-cell leukemia virus type I (HTLV-I), is known to induce accumulation of the unspliced viral gag-pol mRNA. Rex is a phosphoprotein found in the cell nucleolus, whose function may be regulated by its localization and phosphorylation. We have examined the role of phosphorylation on Rex function by using a protein kinase inhibitor, H-7 [1-(5-isoquinolinyl-sulfonyl)-2-methylpiperazine]. Treatment of an HTLV-I infected human T-cell line with H-7 blocked specifically accumulation of the unspliced gag-pol mRNA, resulting in the decreased Gag protein synthesis that corresponds with the decreased in vivo phosphorylation of Rex. In contrast, other viral and cellular products have not been influenced by the level of H-7 used. Therefore, the phosphorylation of Rex is required for the viral RNA partition of HTLV-I.

Oncogenic transformation by the tax gene of human T-cell leukemia virus type I in vitro

Human T-cell leukemia virus type I (HTLV-I) is a causative agent of adult T-cell leukemia (ATL). To elucidate the role of HTLV-I in leukemogenesis, we examined the biological activity of a defective HTLV-I provirus with the env-pX 3' long terminal repeat region cloned from leukemic cells of an ATL patient. Transfection experiments showed growth stimulation of NIH 3T3 cells--growing beyond the saturation density and growing in soft agar. Since the pX sequence is known to encode three proteins, Tax, Rex, and p21x, the biological activity of each pX gene was examined separately. The growth-stimulating activity was induced only by the tax gene in NIH 3T3 cells and Rat-1 cells. Furthermore, the tax gene induced tumorigenicity in nude mice when introduced into Rat-1 cells. Thus, a transcriptional transactivator gene of HTLV-I, tax, is clearly identified as a viral oncogene without a cellular homolog. The transforming activity of tax, possibly via a transcriptional deregulation of cell growth control, may play an important role in leukemogenesis of ATL in addition to its aberrant stimulation of the interleukin 2 system.

Frequent expression of myeloid antigen (CD13) on immature T cells in culture

Leukemic cells from 12 patients with lymphoblastic lymphoma (LBL) and T cell acute lymphoblastic leukemia (T-ALL) were studied to determine the inducibility of myeloid antigens in culture in the presence and absence of 12-O-tetradecanoylphorbol-13-acetate (TPA) in association with discrete phenotypic and genotypic analyses on these cells. The investigation revealed that leukemic cells corresponding to common or mature thymocytes were never induced to express any myeloid antigens, and showed rearrangements of T cell antigen receptor (TcR) beta and gamma chain genes. Concomitant examination on leukemic cells from mature T cell malignancies, including adult T cell leukemia (ATL), T cell chronic lymphocytic leukemia (T-CLL) and T cell non-Hodgkin's lymphoma (T-NHL), also failed to express myeloid antigens in culture. By contrast, one of the panmyeloid antigens, CD13 (MCS-2) antigen was induced on leukemic cells corresponding to early thymocytes in 5 out of 7 cases in TPA-added culture and in 3 cases even in TPA-free culture. All of these CD13 antigen inducible cases exhibited the germ line configurations of TcR beta and gamma chain genes except for one case of T-ALL with sole TcR gamma chain gene rearrangement. These findings suggest that primitive T cells, still not undergoing TcR gene rearrangements, retain the characteristics of multipotent progenitor cells to possess different lineage markers and are able to express myeloid antigen not exceptionally. Both phenotypically and genotypically immature thymocytes are considered to be less restricted in the differentiation pathway of hematopoietic cells committed to T cell lineage.

Genetic heterogeneity in blast crisis of chronic myelocytic leukemia

Fourteen patients with lymphoid and mixed blast crisis (BC) of chronic myelocytic leukemia were studied by immunophenotyping and genotyping. Rearrangements of immunoglobulin heavy chain (IgH), T-cell receptor (TcR) gamma and TcR beta genes were detected in all 14, in nine and in four patients, respectively. Interestingly, more than two rearranged bands of IgH gene in three lymphoid BC and two rearranged bands with germ line band in 1 biphenotypic BC indicated the genetic heterogeneity of the blasts. Some blastic transformations are thought to occur at a more immature stage of hematopoietic differentiation than that indicated by the phenotype and genotype of BC cells.

A mechanism for cross-lineage gene rearrangements in B-cell neoplasm

The organization of immunoglobulin heavy chain (IgH) gene of B precursor cell acute lymphoblastic leukemia (ALL) was examined in order to elucidate the mechanism causing simultaneous TCR gene rearrangements. Study using a 5'D probe lying 20 kb upstream of IgH D region genes was useful to distinguish diversity(D)-joining(J) recombination(DJ) from variable(V)-DJ recombination(VDJ). Indeed, IgH gene structures determined by 5'D study well correlated to those recognized by DJ or VDJ transcripts. IgH gene rearrangements of B precursor cell ALL showed developmentally restricted gene recombination; DJ/DJ genotype in the most immature stage and VDJ/VDJ genotype in the relatively mature stage. B precursor cell ALL with simultaneous rearrangements were frequently found in relatively mature cells, i.e., CD20 expressing cells on their surface. Furthermore, most of such dual genotypic ALL showed that at least one allele of IgH genes was VDJ recombination. This finding suggests that dual genotype was the incidental product by a putative common recombinase during the process of VH gene rearrangements. Moreover, since IgH gene rearrangements of acute unclassified leukemia with dual genotype were DQ52 genotype, which indicates abortive gene rearrangements, it was also thought that dual genotype occurred due to the pluripotentiality of the stem cell.

Nucleolar targeting signal of human T-cell leukemia virus type I rex-encoded protein is essential for cytoplasmic accumulation of unspliced viral mRNA

The posttranscriptional regulator (rex) of human T-cell leukemia virus type I is known to be located predominantly in the cell nucleolus and to induce the accumulation of gag and env viral mRNAs. The N-terminal 19 amino acids of rex-encoded protein (Rex) has been shown to be sufficient to direct hybrid proteins to the cell nucleolus. We have studied the function of the nucleolar targeting signal (NOS) of rex by using full-length proviral DNA and mutant rex expression plasmids. Partial deletions of the NOS sequence abolished the accumulation of unspliced cytoplasmic mRNA, although the gene products of rex mutants were found in the nucleoplasm. These results indicate that NOS sequence, or nucleolar localization of Rex, is essential for Rex function.

Cross-lineage gene rearrangements in human leukemic B-precursor cells occur frequently with V-DJ rearrangements of IgH genes

Gene configurations of immunoglobulin (Ig), T-cell antigen receptor (TCR) beta chain, and T-cell rearranging gene gamma (TRG gamma) were studied in human B-precursor lymphoblastic leukemic cells. These cells were phenotypically classified into three developmental stages (stages II through IV) according to Nadler's criteria. All of them showed the Ig heavy chain (IgH) gene rearrangement, and 67% of the cells in stage IV had the rearranged TRG gamma, albeit seldom in other stages. We further analyzed IgH gene rearrangements in detail using upstream to DH (diversity region of IgH) region probe to distinguish DJ from V-DJ recombination. All dual genotyped cells in each stage except one case in stage II showed the V-DJ rearrangements. This suggests the cross-lineage involvement of the putative recombinase, particularly in the process of V-DJ rearrangements. We next examined the transcriptional status of Ig genes as an indirect reflection of the accessibility of these genes to the recombinase. Properly spliced IgH transcripts of normal size were observed in stage IV and surface Ig positive stage, but not in stage II nor III. However, IgH transcripts of aberrant sizes were seen in stage II, III, and also IV. Cross-lineage gene rearrangements were shown to occur frequently when normally spliced IgH gene begins to be transcribed or just before this. These findings may implicate that V-DJ or V-VDJ gene rearrangements forming functional IgH genes, induce frequently TCR or TRG gene rearrangements. We propose these dual genotypes are different in origin from those observed in stem cell leukemia.

Effects of exercise training on biochemical and biomechanical properties of rat aorta

The authors studied the effect of prolonged physical exercise on the mechanical properties of rat aorta in relation to the amounts and qualities of arterial connective tissue fibrous proteins. Twelve male rats were divided into two groups: 6 sedentary rats (S) and 6 training rats (T), which were forced to swim from nine weeks to twenty-five weeks of age. The ultimate tensile stress and the ultimate tensile extension ratio of ring specimens at the descending thoracic aorta were larger in T than in S (192.3 +/- 47.9 g/mm2, mean +/- SD, vs 147.8 +/- 26.0, p less than 0.05; 3.52 +/- 0.13 vs 3.18 +/- 0.27, p less than 0.05; respectively). The elasticity parameter, calculated by fitting stress-strain curves to exponential function in the stress level of 0-20 g/mm2, was lower in T than in S (1.79 +/- 0.15 vs 2.13 +/- 0.24, p less than 0.01). The contents of elastin (alkali-insoluble elastin preparation) and collagen were higher in T than in S (0.44 +/- 0.11 g/g dry aorta vs 0.30 +/- 0.06, p less than 0.05; 0.15 +/- 0.04 g/g dry aorta vs 0.11 +/- 0.04, NS, respectively). Although the aortic calcium content did not significantly change in the training rats (T 1.17 +/- 0.23 mg/g dry aorta, S 0.95 +/- 0.34), the content of calcium in elastin was lower in T than in S (1.75 +/- 0.51 mg/g dry elastin vs 2.63 +/- 1.00, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Fulminant clonal expansion of large granular lymphocytes. Characterization of their morphology, phenotype, genotype, and function

A 39-year-old woman exhibited abrupt malignant transformation of the large granular lymphocytes (LGL) after a chronic course of T gamma-lymphoproliferative disease (T gamma-LPD). The T gamma-lymphocytes were CD2+, CD3-, CD8-, CD16+, Leu7-, and Leu19+ with morphologic characteristics of LGL. Newly appearing LGL were much larger and had more prominent azurophilic granules. Although fundamentally they had the same phenotype as the LGL in chronic stage, they showed increased Ia-like antigen and decreased CD16 antigen expressions. Immunoglobulin (Ig) G-kappa type monoclonal component was detected in the patient's serum. The LGL showed a germ-line configuration for T-cell receptor (TCR) beta and gamma chain genes, whereas the clonal chromosomal abnormalities indicated the neoplastic nature of the LGL. The LGL exhibited competent natural killer (NK), interleukin 2 (IL2) activated killer (AK), and antibody-dependent cell-mediated cytotoxicity (ADCC) activities. The LGL may have derived from NK cells at their mature stage with prethymic phenotype and may have influenced the homeostasis of the patient's humoral immune response.

Sequence requirements for nucleolar localization of human T cell leukemia virus type I pX protein, which regulates viral RNA processing

The posttranscriptional regulator (p27x-III) of human T cell leukemia virus type I (HTLV-I) is located predominantly in the cell nucleolus. A highly basic amino-terminal sequence (NH2-Met-Pro-Lys-Thr-Arg-Arg-Arg-Pro-Arg-Arg-Ser-Gln-Arg-Lys-Arg-Pro-Pro -Thr- Pro) in this protein, when fused to the amino termini of beta-galactosidase and p40x of HTLV-I, acts as an autonomous signal capable of directing the hybrid proteins to the cell nucleolus.

Two major subgroups of human T-cell leukemia virus-1 in Japan

T lymphocytes of patients with human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy (HAM) were cultured. After cultivating for several months, HAM-derived cell lines were tested for the presence of HTLV-1 proviral genome. We have found two major subgroups, the SacI type and the PstI type, of HTLV-1 by the restriction map analysis. They were almost equally distributed among HAM patients. We have also found two types of the provirus in DNA derived from fresh peripheral blood lymphocytes (PBL) or lymph node cells of adult T-cell leukemia/lymphoma (ATL) patients. The PstI type proviruses were predominant in ATL patients. It was concluded that two major subgroups of HTLV-1 exist in Japan and both types have an ability to cause either of two diseases, ATL or HAM.

Phenotypic conversion of T lymphoblastic lymphoma to acute biphenotypic leukemia composed of lymphoblasts and myeloblasts. Molecular genetic evidence of the same clonal origin

Acute biphenotypic leukemia composed of lymphoblasts and myeloblasts developed in a patient with T lymphoblastic lymphoma (T-LBL) who had an anterior mediastinal mass. A novel myeloid cell line, termed TK-1, has been established from his peripheral blood after the leukemic conversion. The identical rearranged pattern of T cell receptor gamma-chain gene was observed among the DNAs derived from lymph node cells in the lymphoma phase, the myeloid cell line TK-1, and the subclones with different karyotypes (TK-1B and TK-1D), which showed that myeloid cells had been derived from the T-LBL of the same patient. This finding demonstrates that phenotypic conversion occurs in the clonally propagating tumor cells and suggests that some hematopoietic cells retain the capacity to adopt either lineage.

Immunogenotypes of lymphoid malignancies; the rearrangement of T cell receptor beta chain gene can occur before the gamma chain gene rearrangement

Immunoglobulin (Ig) and T cell receptor (TcR) gene rearrangements were analyzed in 101 cases of lymphoid malignancies in association with a surface phenotype study. In leukemias/lymphomas with mature phenotype, there is a good correlation between phenotypes and genotypes. However, in leukemias/lymphomas with immature phenotype, we found many discordances between phenotypes and genotypes, suggesting the stochastic nature of hematopoietic cell differentiation at the early stage. As for TcR beta and gamma chains, the rearrangement of gamma chain gene is considered to occur slightly prior to that of beta chain gene. However, we observed a mature T cell malignancy, adult T-cell leukemia, with rearranged beta chain gene and germ line gamma chain gene, showing the possible existence of another pathway of T cell differentiation.

[Combined clinical effect of amikacin and cefoxitin in patients with severe infections complicated by hematological diseases]

A clinical investigation was made on the concurrent use of amikacin (AMK) and cefoxitin (CFX) against complicated infections with hematological disorders. The results obtained were summarized as follows: Eleven patients were treated with AMK and CFX. Clinical responses were excellent in 2 (18%), good in 4 (36%), fair in 1 (9%), and poor in 4 (36%), with an efficacy rate of 64%. No significant side effects requiring cessation of the treatment were observed.