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Biomedical subjects

M Yasukawa

Publications and source records attributed to M Yasukawa.

At least 19 recordsLinked to original sources

SFA-2, a novel bZIP transcription factor induced by human T-cell leukemia virus type I, is highly expressed in mature lymphocytes.

A novel cellular gene, SFA-2, was isolated by differential hybridization of a cDNA library, using probes obtained from an adult T-cell leukemia cell line in comparison with normal CD4+ T cells and MOLT-4 cell line. The mRNA of the SFA-2 gene is approximately 0.9-kb in size and encodes a protein of 125 amino acids, containing a basic region-leucine zipper DNA-binding domain. The N-terminal region of SFA-2 is rich in serine and contains a consensus sequence for casein kinase II phosphorylation. The SFA-2 gene was strongly expressed in mature T and B lymphocytes, and was up-regulated after transformation by human T-cell leukemia virus type I. The SFA-2 did not homodimerize efficiently but formed heterodimer preferentially with c-Jun. The SFA-2/c-Jun heterodimer bound preferentially to the AP-1 and CRE sites.

Amino Acid Sequence

Two distinct mechanisms of cytotoxicity mediated by herpes simplex virus-specific CD4+ human cytotoxic T cell clones.

The present study was undertaken to elucidate the mechanisms responsible for the cytotoxicity of herpes simplex virus (HSV)-specific CD4+ human cytotoxic T lymphocyte (CTL) clones, focusing on perforin and membrane-bound lymphotoxin (LT) (tumor necrosis factor-beta). Two HSV-specific CD4+ CTL clones, which expressed both perforin and membrane-bound LT, exerted HSV-specific cytotoxicity and cytotoxicity against LT-sensitive L929 cells. These CD4+ CTL clones lysed HSV-infected cells directly in an HLA class II-restricted manner and did not exhibit "bystander killing." The culture supernatants of these clones stimulated with HSV antigen showed no cytotoxicity against HSV-infected cells or L929 cells, suggesting that adhesion to target cells is essential to their antigen-specific and antigen-nonspecific cytotoxicities. The cytotoxicities of these clones against HSV-infected autologous cells were inhibited by an anti-CD3 monoclonal antibody but not by an anti-LT antibody. Conversely, their cytotoxicities against L929 cells appeared to be partially inhibited by the anti-LT antibody but not by the anti-CD3 monoclonal antibody. Furthermore, target cell DNA fragmentation induced by these CD4+ CTL clones was apparently observed in L929 cells but only faintly detected in HSV-infected autologous cells. L929 cell DNA fragmentation was also inhibited by adding the anti-LT antibody to CD4+ CTL cultures. These data suggest that some CD4+ CTL possess at least two cytolytic mediators, i.e., perforin and membrane-bound LT simultaneously, and can exert both antigen-specific cytotoxicity via two distinct mechanisms, necrosis and apoptosis.

Antibodies, Monoclonal

Molecular cloning of a cDNA encoding enolase from the filamentous fungus, Aspergillus oryzae.

A 1.6-kbp full-length cDNA for the Aspergillus oryzae enolase gene (enoA) was cloned. The sequenced insert contained a continuous open reading frame of 1314 bp encoding a protein of molecular weight 47 405. Among all enolases sequenced to-date, the deduced amino-acid sequence showed the highest homology (74.9%) with Candida albicans enolase (ENO1). Strong codon biases and multiple transcription start sites downstream from CT-blocks in the 5'-flanking region suggested strong expression. enoA mRNA was found to occupy approximately 3% (w/w) of total mRNA of A. oryzae by quantitative RT-PCR. This strong transcription was dependent on the carbon source in the medium and correlated with the growth rate of the mycelium.

Amino Acid Sequence

Diverse effects of tumor necrosis factor-alpha on three subclones from human myelomonocytic leukemia cell line ME-1 exhibiting different differentiation stages.

The effects of tumor necrosis factor-alpha (TNF-alpha) were examined in three subclone cells from human myelomonocytic leukemia cell line ME-1. These three subclone cells exhibit different differentiation stages of the myelomonocytic lineage. TNF-alpha exerted a growth-suppressive effect on the least mature subclone cells, ME-F2 cells. On the other hand, TNF-alpha induced the most mature ME-F1 cells and intermediate ME-F3 cells to differentiate along the monocytic pathway. TNF-alpha also enhanced interferon-gamma (IFN-gamma)-induced complement C2 production by ME-F1 and ME-F3 cells but did not affect production by differentiated ME-F1 and ME-F3 cells. These results suggest that the diversity of the effects of TNF on subclone cells from ME-1 depends on the stage of cell differentiation.

Cell Differentiation

Detection of human herpesvirus 6 and human herpesvirus 7 in the submandibular gland, parotid gland, and lip salivary gland by PCR.

In order to define the major sites of persistence of human herpesvirus 6 (HHV-6) and HHV-7, PCR with DNAs from more than 100 specimens of 3 different salivary glands was performed. HHV-6 DNA was detected in 52 (88.1%) of 59 submandibular gland, 17 (63.0%) of 27 parotid gland, and 9 (52.9%) of 17 lip salivary gland specimens. On the other hand, HHV-7 DNA was detected in 59 (100%) of 59 submandibular gland, 23 (85.2%) of 27 parotid gland, and 10 (58.8%) of 17 lip salivary gland specimens. These findings demonstrate that salivary glands are a site of persistent infection of both HHV-6 and HHV-7 and that among the three types of salivary gland examined, the submandibular gland is the primary one in which these herpesviruses, especially HHV-7, persist.

Herpesvirus 6, Human

Application of long-distance PCR to restriction site mapping of a cloned DNA fragment on the lambda EMBL3 phage vector.

Long-distance PCR was applied to rapidly map the restriction sites of long inserts cloned on lambda EMBL3 phage vector. The restriction sites of 9 of 15 enzymes were completely assigned in a model experiment within 14 h, including 8h for the PCR amplification. This method was found particularly useful for genomic DNA cloning when the partial sequence of the corresponding cDNA is known.

Bacteriophage lambda

Adenoid cystic carcinoma arising in the intrapulmonary bronchus.

A 63-year-old male was admitted to our hospital because of a coin lesion in the intrapulmonary bronchus. The patient had no symptoms such as cough or sputum. Imaging studies showed that the tumor was present in the S10b,c of the right lung. There was no metastasis or salivary gland tumor. Transbronchial tumor biopsy revealed a primary adenoid cystic carcinoma. The patient underwent a lobectomy, and has been well since the operation. This is an uncommon case of primary adenoid cystic carcinoma arising from the intrapulmonary bronchus.

Bronchial Neoplasms

[Successful treatment of combined interferon-alpha and hydroxycarbamide for chronic myelogenous leukemia following therapy for malignant lymphoma].

A 57-year-old woman was diagnosed as having non-Hodgkin lymphoma (follicular mixed cell, B-cell type, Stage III) in February 1988. Since then, she had been treated with radiation and chemotherapy contained with alkylating agents and etoposide for 6 years. In April 1994, peripheral blood study disclosed leukocytosis with basophilia and thrombocytosis. Bone marrow was hypercellular. The karyotype of bone marrow cells was 46, XX, t(9:22) (q34:q11). Rearrangement of bcr was detected in bone marrow, but not in lymph node cells. On the basis of these findings, she was diagnosed as having the chronic phase of chronic myelogenous leukemia (CML) following the therapy for malignant lymphoma and treated with interferon-alpha (IFN-alpha) and hydroxycarbamide. Following this therapy, the lymphoadenopathy promptly disappeared and chromosome analysis showed disappearance of Ph chromosome positive cells. Although CML is rare in secondary leukemia, the present case seemed therapy-related CML and the treatment with IFN-alpha and hydroxycarbamide was effective for both CML and malignant lymphoma.

Antineoplastic Agents, Alkylating

[Prognostic diagnosis of facial palsy with electroneuronography].

We examined the accuracy of electroneuronography (ENoG) as a prognostic indicator in 58 patients with facial palsy: 47 patients with Bell's palsy and 11 patients with Ramsay-Hunt syndrome over a period of one year. For surface recording, the active electrodes were placed over the orbicularis oculi, orbicularis oris, quadratus labii, nasal alae or nasolabial fold, and the indifferent electrode over the same muscle in the opposite side. ENoG over nasal alae showed the most reliable value and the next was orbicularis oris. All other muscles were less reliable. We found that in 87.2% of cases, recovery was satisfactory in Bell's palsy and 63.6% cases in Ramsay-Hunt syndrome. Of the 47 Bell's palsy patients, 38 patients (80.9%) had a response to ENoG over nasal alae of 10% or greater, while 5 patients (45.5%) of the 11 patients with Ramsay-Hunt syndrome. All these patients recovered satisfactorily within four months. Nine of 47 patients (19.1%) with Bell's palsy and 6 of 11 patients (54.5%) with Ramsay-Hunt syndrome had a response of 10% or less. Satisfactory recovery rate among these patients was 33.3%. In conclusion, ENoG over nasal alae and orbicularis oris shows reliable values among other muscles. Patients with responses to ENoG over nasal alae of 10% or greater showed satisfactory recovery.

Adolescent

CD4 down-modulation by ganglioside and phorbol ester inhibits human herpesvirus 7 infection.

Recently, data demonstrating that CD4 is an essential component of the receptor for human herpesvirus 7 (HHV-7) as well as for human immunodeficiency virus have been accumulating. Since gangliosides and phorbol esters are known to induce selective down-modulation of cell surface CD4 expression, it might be expected that treatment with these agents would interfere with HHV-7 infection of CD4+ T cells. The present study, undertaken to verify this possibility, demonstrated that addition of monosialoganglioside-GM1 or 12-O-tetradecanoylphorbol 13-acetate effectively induced disappearance of CD4 from the cell surface and also reduced HHV-7 infectivity, as judged by the CPE on virus-infected cells and studies of indirect immunofluorescence, TCID50 and semi-quantitative PCR of the HHV-7 genome. Taken together with previous studies, the present data strongly suggest that the CD4 molecule is a critical component of the receptor for HHV-7.

Antigens, Viral

Monoclonal proliferation of CD4+ large granular lymphocytes with cytolytic activity.

A rare case of monoclonal proliferation of CD3+4+8- T-cell receptor-alpha beta+ large granular lymphocytes (LGL) is presented. CD4+ LGL in the present case showed spontaneous cytotoxicity against herpes simplex virus-infected cells and antibody- and lectin-dependent cytotoxicity. Perforin, which is one of the important cytolytic mediators of cytotoxic T cells (CTL) and natural killer cells, was abundantly expressed in CD4+ LGL of this case. The present case suggests that perforin-positive CD4+ CTL, which have recently been shown in the in vitro studies, certainly exist in vivo.

Aged

Immortalization of human T cells expressing T-cell receptor gamma delta by herpesvirus saimiri.

Herpesvirus saimiri (HVS) has recently been shown to immortalize human CD4+ and CD8+ T cells expressing T-cell receptor alpha beta (TCR-alpha beta) with the maintenance of their original phenotypes and functional properties. However, the immortalization of human T cells expressing TCR-gamma delta by HVS has not been successful. Here we report that HVS can also infect and immortalize human T cells expressing TCR-gamma delta. Two human TCR-gamma delta+ T-cell clones, which continuously proliferated in interleukin-2-containing culture medium without any exogenous stimulation or addition of feeder cells for more than 8 months, were established by HVS infection. Morphologically, the HVS-transformed TCR-gamma delta+ T-cell clones were granular lymphocytes which exhibited wide-range HLA-unrestricted cytotoxicity as untransformed TCR-gamma delta+ T cells. Their phenotypes and cytotoxic activities were not altered during long-term culture. The immortalization of human TCR-gamma delta+ T cells by HVS infection would be useful for functional analysis of this lymphocyte population, which is believed to play an important role in protection against various infectious diseases.

Animals

Total body fat estimations by near-infrared interactance, A-mode ultrasound, and underwater weighing.

We studied 94 (41 men and 53 women) healthy 18 to 65 years old Caucasians for body composition utilizing 3 methods: 1) Underwater weighing (UWW) for body density, 2) A-mode ultrasound subcutaneous fat determination, and 3) Near-infrared (NIR) interactance spectral data. We then utilized the Wherry-Doolittle test selection method to predict percent of total body fat (%fat) from either ultrasound or NIR data with anthropometric measurements, optimizing for the fewest number of data points which correlated highly with UWW results. It was found that %fat could be estimated with a correlation of > 0.9 when measured at 4 sites (different between men and women) by ultrasound, age (women) and height (men). We also found a correlation of > 0.8 using 2 sites by NIR, weight, age, and height. It has been suggested that the ultrasound method would produce better estimates of both local and total body fat.

Adipose Tissue

[Low titer cold agglutinin disease due to anti-HI antibody and a review of this disease in Japan].

A 79 year-old Japanese man was admitted because of brownish urine and Raynaud phenomenon. Laboratory data showed mild anemia with reticulocytosis, positive direct Coombs test against anti-C3, elevated level of lactate dehydrogenase, undetectable level of serum haptoglobin and low titer of cold agglutinin (1:256 at 4 degrees C), the immunoglobulin subclass of which was IgM. Cold agglutinin disease is usually associated with very high levels of cold agglutinins, the specificity of which is anti-I. This case had low titer cold agglutinin disease due to anti-HI cold agglutinin.

Adolescent

[CD5-negative B-cell chronic lymphocytic leukemia (B-CLL) associated with massive splenomegaly and without lymphadenopathy].

A 39-year-old male was referred to our hospital in June, 1993, because of leukocytosis. Physical examinations showed massive splenomegaly without any lymphadenopathy. The white blood cell count was 13,800/microliters with 87% morphologically mature lymphocytes. Bone marrow aspirate revealed hypercellularity with 67% lymphocytes morphologically similar to peripheral lymphocytes. The lymphocytes displayed monoclonal rearrangements of immunoglobulin genes and the phenotype of CD5-CD19+CD20+ CD21+ and Smlg+. Splenectomy was effective against neutropenia and thromboytopenia. The clinical and laboratory findings of this case were unusual compared to those of typical B-CLL in massive splenomegaly, no lymphadenopathy and CD5-phenotype, suggesting the heterogeneity of B-CLL.

Adult