PubMed Health⌕ Search

Biomedical subjects

T Toyosaki

Publications and source records attributed to T Toyosaki.

At least 19 recordsLinked to original sources
PubMed2001

Colonization with Schizophyllum commune of localized honeycomb lung with mucus.

We report a surgical case involving localized honeycomb lung with mucus, caused by colonization of a Schizophyllum commune, which displayed a tumorous shadow in the right upper mediastinum. A 74-year-old male with a history of tuberculosis in the 1970s was referred to Chiba University Hospital (Chiba, Japan) with an abnormal shadow evident in the chest roentgenogram. A transbronchial biopsy failed to yield a definite diagnosis. We resected the right upper lobe, which was found to contain a consolidative lesion filled with viscous mucus in the right upper lobe adjacent to the right upper mediastinum. Microscopic examination revealed a honeycomb lung formation with mucus in the destroyed space. Culture of the mucus yielded a whitish filamentous fungus, positively identified as S. commune. This is the first report of S. commune leading to a deposit of mucus and the formation of a consolidative lesion in the destroyed lung.

Aged↗
PubMed2000

Apoptotic cell death in arrhythmogenic right ventricular cardiomyopathy: a comparative study with idiopathic sustained ventricular tachycardia.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a specific heart muscle disease of unknown etiology characterized by fatty and fibrofatty replacement of the right ventricular myocardium. It often manifests life-threatened ventricular arrhythmias. Previous studies have hypothesized that myocyte apoptosis contributes to the myocyte cell loss and fatty change in ARVC and may be induced by recurrent ventricular tachycardia (VT). We examined whether these progressive pathological changes result from apoptotic cell death in both autopsied and biopsied right ventricular myocardium from 35 patients with ARVC by using in situ terminal deoxynucleotidyl transferase assay (TUNEL) and agarose gel electrophoresis. We also studied the biopsied myocardium from 30 patients with idiopathic sustained VT whose origin was the outflow tract of the right ventricle. TUNEL-positive cells indicating DNA fragments were observed in some cardiomyocytes and fibroblasts in ARVC, but the numbers of TUNEL-positive myocytes were very low in idiopathic VT. DNA laddering was confirmed in two autopsied cases in ARVC, but not in a non-cardiac case who died. These results suggest that at least some cardiomyocytes and fibroblasts are subjected to apoptosis in ARVC, leading to the loss of myocardium with characteristic pathological changes and subsequently progressive cardiomyopathy. Furthermore, the apoptotic process may not result from myocardial ischemia due to repetitive VT.

Adolescent↗
PubMed1998

Nurse-like cells from bone marrow and synovium of patients with rheumatoid arthritis promote survival and enhance function of human B cells.

Thymic nurse cells are known to interact with T cells and play a role in their functional maturation. However, the role of nurse cells in B cell maturation and differentiation is less well established, especially at extralymphoid sites. To address this issue, nurse-like cell clones from bone marrow and synovial tissue of patients with RA (RA-NLC) were established and characterized. RA-NLC constitutively expressed CD29, CD49c, CD54 (ICAM-1), CD106 (VCAM-1), CD157 (BST-1), and class I MHC molecules, and secreted IL-6, IL-7, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF). Bone marrow-derived and synovial RA-NLC differed in that the former secreted IL-7 and expressed a greater density of CD157 constitutively and after stimulation with IFNgamma, whereas the latter secreted G-CSF and more IL-6. Stimulation of both bone marrow and synovial RA-NLC induced expression of CD40 and class II MHC, but not CD154 (CD40L) or CD35. RA-NLC rescued peripheral B cells from spontaneous apoptosis and promoted survival of B cells for > 4 wk. B cell survival was blocked by antibodies to CD106 or CD157. RA-NLC also increased Ig production from B cells. After long-term culture (4-6 wk) with RA-NLC, but not alone or with fibroblasts, outgrowth of B cells was observed. All B cell lines derived from these cultures had been transformed by EBV, although the RA-NLC themselves were not infected with EBV. Precursor frequency analysis indicated that approximately 1 in 12,500 peripheral B cells could give rise to these EBV-transformed B cell lines upon coculture with RA-NLC. These results indicate that RA-NLC from bone marrow and synovium have the capacity to rescue B cells from spontaneous apoptosis, facilitate Ig production, and promote the outgrowth of EBV-transformed B lymphoblastoid cells. These findings suggest that RA-NLC may play a role in the local and systemic hyperreactivity of B cells characteristic of rheumatoid arthritis.

Antibody Formation↗
PubMed1998

Recognition of rheumatoid arthritis synovial antigen by CD4+,CD8- T cell clones established from rheumatoid arthritis joints.

OBJECTIVE: To investigate the rheumatoid arthritis (RA)-specific autoantigen(s) recognized by CD4+ T cells in patients with RA. METHODS: CD4+,CD45RO+ T cell clones were established from the joints of RA patients, and were examined for their proliferative response to synovial cells. RESULTS: Eight of 146 T cell clones responded to RA synovial cells in a DR-restricted manner. These T cell clones recognized solubilized antigens extracted from RA synovial cells in the presence of DR-matched antigen-presenting cells, but did not respond to those extracted from non-RA synovial cells. The antigens had a molecular weight of 50/25 kd. Five of the 8 T cell clones used T cell receptor BV6, and the remaining clones used BV12.2. CONCLUSION: The antigens recognized by joint-infiltrating CD4+ T cells are present exclusively in RA synovial cells. The expression of these antigens by synovial cells may trigger the autoreactivity of T cells in RA joints.

Amino Acid Sequence↗
PubMed1998

Proinflammatory cytokines detectable in synovial fluids from patients with temporomandibular disorders.

OBJECTIVE: To measure the levels of the proinflammatory cytokines, interleukin (IL)-1 beta, IL-6, tumor necrosis factor- (TNF) alpha, IL-8, and interferon- (IFN) gamma in synovial fluid samples taken from patients with temporomandibular disorders (TMD). STUDY DESIGN: We studied 6 asymptomatic volunteers and 51 patients with TMD. The IL-1 beta, IL-6, TNF-alpha, IL-8, and IFN-gamma levels in temporomandibular joint synovial fluid were measured using enzyme-linked immunosorbent assay. RESULTS: Measurable level of at least one cytokine in the synovial fluid was found in 40 (64.5%) of 62 joints in the patients: IL-1 beta and IFN-gamma were each detected in 18 (29.0%) of 62 joints; IL-6 in 13 (21.0%) of 62 joints; IL-8 in 11 (19.3%) of 57 joints; and TNF-alpha in only 5 (8.1%) of 62 joints. None of these cytokines was detectable in the synovial fluid in the control group. Furthermore, there was a strong correlation between the detection of IL-1 beta and pain in the joint area. CONCLUSIONS: These data clearly demonstrate increased levels of several proinflammatory cytokines in certain patients with TMD and suggest that these cytokines may play a role in the pathogenesis of synovitis and degenerative changes of the cartilaginous tissue and bone of the temporomandibular joint.

Adolescent↗
PubMed1998

Eight-year observation and comparative study of specific pathogen-free cats experimentally infected with feline immunodeficiency virus (FIV) subtypes A and B: terminal acquired immunodeficiency syndrome in a cat infected with FIV petaluma strain.

Three specific pathogen-free cats experimentally infected with feline immunodeficiency virus (FIV) strains Petaluma, TM1 and TM2, respectively were observed for over 8 years. Without showing any significant clinical signs of immunodeficiency syndrome (AIDS) for 8 years and 4 months of asymptomatic phase, the Petaluma-infected cat exhibited severe stomatitis/gingivitis, anorexia, emaciation, hematological and immunological disorders such as severe anemia, lymphopenia, thrombocytopenia, and decrease of CD4/CD8 ratio to 0.075, and finally died with hemoperitoneum at 8 years and 8 months post-infection. Histopathological studies revealed that the cat had systemic lymphoid atrophy and bone marrow disorders indicating acute myelocytic leukemia (aleukemic type). Plasma viral titer of the cat at AIDS phase was considerably high and anti-FIV antibody titer was slightly low as compared with the other FIV-infected cats. In addition, immunoblotting analysis using serially collected serum/plasma samples of these cats revealed that antibodies against FIV proteins were induced in all the infected cats, however in the Petaluma-infected cat anti-Gag antibodies disappeared during the asymptomatic period. These results suggested that plasma viral load and anti-FIV Gag antibody response correlated with disease progression, and supported FIV-infected cats as a suitable animal model of human AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Quantitative analysis of the usage of human T cell receptor alpha and beta chain variable regions by reverse dot blot hybridization.

We previously developed an adaptor ligation-mediated PCR method to amplify the T cell receptor (TCR) cDNA pools. In the present study we applied reverse dot blot hybridization to PCR-amplified specimens for quantitative analysis of the usage of TCR alpha and beta chain variable (V) region. 44 VA sequence-specific oligonucleotide probes (SSOPs) and 38 VB SSOPs were synthesized corresponding to unique sequences of VA and VB subfamilies. Peripheral blood lymphocytes of ten healthy donors and five T cell clones established from bone marrow cells were examined for VA and VB usage using this method. The results were consistent with those obtained by a colony hybridization method and those by immunofluorescence staining using monoclonal antibodies to VA and VB. Thus, reverse dot blot hybridization for TCR V(alpha) and Vbeta is a new, easy and dependable technique useful for analysis of VA and VB usage by human T cells.

Base Sequence↗
PubMed1996

Establishment and characterization of an anti-idiotypic CD4+ CD8- T cell line to murine anti-alpha(1 --> 3) dextran antibody.

It is known that anti-alpha(1 --> 3) dextran antibodies of BALB/c mice are ordinarily of distinctive idiotypes (Id), one of which is the individual idiotype (IdI) that is represented by J558 or M104E to myeloma protein. In the present study, we established T cell line of Th1 type which recognized the Id of anti-alpha(1 --> 3) dextran antibody, and investigated its specificity and functions. The T cell line, named J-2R, had a phenotype of CD3+ CD4+ CD8- and expressed alphabeta-T cell receptors (TcR). J-2R proliferated in response to J558 in an I-Ed-restricted manner but did not respond to M104E which had substitution at amino acids 100 and 101. We confirmed that J-2R recognized J558 IdI, using synthetic peptides corresponding to two serial amino acid residues, Arg100 and Tyr101, spanning the J558 IdI in the third hypervariable region (hv3) of the heavy chain. alpha(1 --> 3) dextran-binding B cells which were isolated from dextran-immunized mice activated J-2R, but B cells from nonimmune mice did not. J-2R produced IL-2, IFN-gamma and IL-6, but did not produce IL-4, IL-5, or IL-10. Furthermore, J-2R inhibited the growth of J558 myeloma cells inoculated to the syngeneic mice in vivo. These findings suggest that Id-specific CD4+ T cells, J-2R, are involved in Id network and may play a role in vivo. J-2R is useful for analysis of the role of the Id-specific helper T cells in immune network because J558 IdI is frequently present on anti-alpha(1 --> 3) dextran antibodies.

Amino Acid Sequence↗
PubMed1996

Definition of the mitogenic factor (MF) as a novel streptococcal superantigen that is different from streptococcal pyrogenic exotoxins A, B, and C.

Human T cell activation by recombinant mitogenic factor (rMF) was investigated in comparison with that by recombinant streptococcal pyrogenic exotoxins (rSPE) A, B, and C. Recombinant MF, rSPEA, and rSPEC were mitogenic for peripheral blood mononuclear cells (PBMC), whereas rSPEB was not. Recombinant MF required only HLA-DR for the stimulation of PBMC, as determined using monoclonal antibodies (mAb) to HLA class II molecules and the mouse L cells transfected with HLA class II molecules. Recombinant SPEA and rSPEC required HLA-DR or HLA-DQ molecule. Recombinant MF selectively stimulated V beta 2, V beta 7, V beta 8, V beta 18 and V beta 21-bearing T cells, whereas rSPEA and rSPEC activated V beta 2 and V beta 6-bearing T cells as evaluated by the quantitative T cell receptor (TCR) analytical method. No clonality was observed in the nucleotide sequences of complementarity determining region 3 of TCR V beta in T cells responding to rMF. The profiles of cytokine production by PBMC in response to rMF, rSPEA, and rSPEC were quite similar. In summary, these results demonstrate that both HLA class II molecules and the TCR V beta required for rMF-mediated T cell activation are distinct from those required for rSPEA or rSPEC-mediated activation. Therefore, the MF is a novel streptococcal super-antigen which is different from SPEA, SPEB, and SPEC.

Bacterial Proteins↗
PubMed1996

Effects of the new calcium antagonist efonidipine hydrochloride on resting and exercise hemodynamics in patients with stable effort angina.

The action of efonidipine hydrochloride ((+/-)-2-[benzyl(phenyl)-amino]ethyl 1,4-dihydro-2,6-dimethyl-5-(5,5-dimethyl-2-oxo-1, 3,2-dioxaphosphorinan-2-yl)-4-(3-nitrophenyl)-3-pyridinecarboxy late hydrochloride ethanol, CAS 1110011-76-8, NZ-105) a new dihydropyridine calcium antagonist, on cardiac hemodynamics at rest and during exercise as well as plasma concentration and pharmacokinetic parameters were studied in 9 patients with angina pectoris. NZ-105 was administered 40 mg once daily for a week and cardiac hemodynamics parameters were measured at rest and during exercise using a bicycle ergometer before and after treatment. All patients showed anginal symptoms during exercise before treatment, while only 4 showed anginal symptoms during exercise after treatment. Improvement on electrocardiograms (ECG) (> 0.1 treatment mV) was detected in 4 out of 9, and NZ-105 was recognized to have an anti-anginal action. The mean plasma concentration of NZ-105 at the time was 14.5 ng/ml. At rest, reduction in blood pressure and decrease in total peripheral vascular resistance were observed, however, NZ-105 showed no effect on heart rate, cardiac index, pulmonary arterial pressure and central venous pressure. During maximum exercise, a decrease in total peripheral vascular resistance, reduction in pulmonary arterial pressure and central venous pressure, increasing tendency of left ventricular ejection fraction, and increase in cardiac index were observed. However, NZ-105 showed no effect on heart rate and blood pressure. Based on the results mentioned above, cardiac hemodynamics of NZ-105 during exercise, featured primarily, reduction of afterload and improvement of cardiac functional deterioration due to exercise. In conclusion, NZ-105 is useful in patients with ischemic cardiac diseases by improving hemodynamics and ECG findings during exercise in patients with effort angina.

Angina Pectoris↗
PubMed1994

Establishment and characterization of nurse cell-like clones from human skin. Nurse cell-like clones can stimulate autologous mixed lymphocyte reaction.

We have established nurse cell-like clones from long-term cultures of the human skin. These human skin nurse cell (HSNC)-like clones were type I collagen+, type IV collagen-, vimentin+, cytokeratin-, CD44+, CD54+, and weakly positive for VCAM-1, and easily identified by the pseudoemperipolesis that allowed T lymphocytes to migrate beneath the HSNCs. HSNCs and various T cell lines formed a typical complex in the hanging drop culture system. The majority of human and murine T cells, and some of the tumor cell lines other than T cells, including B lymphoma and myeloblastoma cells, migrated beneath the HSNC clones. HSNC clones produced various cytokines, including IL-6, IL-7, IL-8, IL-9, granulocyte CSF (G-CSF), granulocyte-macrophage CSF (GM-CSF), macrophage CSF (CSF-1), TGF-beta 1, and c-kit ligand, but could not produce IL-1 alpha, IL-1 beta, IL-2, IL-3, IL-4, TNF-alpha, or TNF-beta. These characteristics were similar to those of nurse cells established from the murine thymus. Furthermore, IFN-gamma-pretreated HSNC clones that expressed MHC class II Ags induced autologous mixed lymphocyte reaction (AMLR) in autologous PBMCs to proliferate and exhibit the cytotoxicity against altered autologous cells and various tumor cells. These results suggest that HSNCs play an important role in the immunoregulation at skin tissues.

Animals↗
PubMed1994

Isolation, sequence and expression of a cDNA encoding the alpha-chain of the feline CD8.

We have cloned, sequenced and expressed a cDNA encoding the alpha-chain of feline CD8. This clone, named FT8-10, has an open reading frame with 720 nucleotides in length encoding a protein with 239 amino acid residues. Sequence analysis has revealed that the feline CD8 alpha-chain (CD8 alpha) shares significant homology with human (T8/Leu-2), bovine (BoCD8), rat (MRC OX8) and mouse (Lyt-2) CD8 alpha subunits. Cysteine residues as well as the tyrosine kinase p56lck binding site are well conserved. Besides, no putative N-linked glycosylation site was found. Interestingly, immunofluorescence analysis of COS-7 cells transfected with feline CD8 alpha expression plasmid driven by SR alpha promoter showed that the expressed feline CD8 alpha cross-reacted with an anti-human CD8 alpha monoclonal antibody OKT8, but did not react with an anti-feline monoclonal antibody, FT-2, which is thought to recognize the feline analogue of the human T8/Leu-2 and murine Lyt-2 molecules expressed on cytotoxic/suppressor T cells.

Amino Acid Sequence↗
PubMed1993

Feline CD4 molecules expressed on feline non-lymphoid cell lines are not enough for productive infection of highly lymphotropic feline immunodeficiency virus isolates.

To investigate whether the feline CD 4 (fCD4) molecules are involved in infections of highly lymphotropic feline immunodeficiency virus (FIV) isolates, we expressed fCD4 stably on Crandell feline kidney cells and Felis catus whole foetus 4 cells by transfection of a cDNA encoding the fCD4 glycoprotein, and then infected them with TM 1 and TM 2 strains of FIV, which are unable to infect these cells productively. In spite of fCD 4 being expressed on these cells, no virus production was observed. This result indicates that fCD 4 expression alone cannot induce a productive infection of the FIV TM 1 and TM 2 strains.

Animals↗
PubMed1993

Localization of the viral antigen of feline immunodeficiency virus in the lymph nodes of cats at the early stage of infection.

Immunohistochemical examinations of localization of feline immunodeficiency virus (FIV) Gag protein were performed on lymph nodes of cats experimentally inoculated with three different strains of FIV (infectious molecular clone of TM 1, Petaluma, and KYO-1 strains), using rabbit anti-FIV Gag serum. The FIV Gag antigens were observed in many follicular dendritic cells (FDCs) and sparsely in small lymphocytes of paracortical area in the lymph nodes of cats inoculated with Petaluma and KYO-1 strains. However, the antigens were present only in small lymphocytes, and not in FDCs of a cat inoculated with infectious molecular clone of the TM1 strain. The cell type differences in expression of the viral antigen in vivo might reflect on the cell tropisms of the FIV strains in vitro. By double immunohistochemical staining with rabbit anti-FIV Gag serum and monoclonal antibodies which recognize feline CD4, feline CD8 or feline pan-T molecules, the FIV Gag-positive lymphocytes were characterized as feline CD4-positive T cells. Since the distributions of FIV Gag antigens were mainly in the FDCs, the FDCs may play an important role as a major reservoir and may be a primary target of FIV at early stages of infection.

Animals↗
PubMed1993

The AP-1 binding site in the feline immunodeficiency virus long terminal repeat is not required for virus replication in feline T lymphocytes.

Sequences of 31 bp containing putative AP-1 and AP-4 binding sequences in the U3 region of the feline immunodeficiency virus (FIV) long terminal repeat (LTR) were deleted and the basal promoter activity of the LTR was measured by the chloramphenicol acetyltransferase (CAT) assay. The activity of the FIV LTR was reduced in Felis catus whole foetus 4 (fcwf-4) cells and Crandell feline kidney cells by this deletion. Cotransfection of murine c-Fos or c-Jun expression plasmids with the FIV LTR-CAT reporter plasmid into fcwf-4 cells revealed that FIV LTR could be activated by c-Fos but not c-Jun in the cells. The mutated LTR was introduced into an infectious molecular clone of FIV and the replication rate and the cytopathogenic activity of the mutant were compared with those of the wild-type in two feline CD4-positive T lymphoblastoid cell lines. It was found that the rate and activity of the mutant were almost the same as those of the wild-type. From these data, we conclude that the 31 bp fragment is important for achieving maximal expression of the FIV genome, but not required for the replication of FIV in feline T lymphocytes.

Animals↗
PubMed1992

Identification of a feline immunodeficiency virus gene which is essential for cell-free virus infectivity.

Feline immunodeficiency virus (FIV) contains at least three small open reading frames (ORFs) in the genome, in addition to the three structural genes. Two of these ORFs (putative vif and ORF-A) have unknown functions. Northern (RNA) blot analysis of mRNAs from an FIV-infected cell line showed that the putative-vif-specific mRNA was expressed as a 5.2-kb species. To examine the function of the putative vif gene, we constructed mutants carrying a deletion in either the vif-like gene or the rev gene from an infectious molecular clone of FIV. Although the vif mutant produced virion-associated reverse transcriptase at a normal level upon transfection, cell-free virus prepared from the transfected cells could not infect feline CD4+ cells. The infectivity of the vif mutant, however, was demonstrated in a coculture of the transfected cells and feline CD4+ cells. We conclude that FIV contains the vif gene, which is structurally and functionally similar to that of the primate lentiviruses.

Base Sequence↗
PubMed1992

Monoclonal antibodies to feline lymphocyte membranes recognize the leukocyte-common antigen (CD45R).

By immunization of BALB/c mice with a feline T lymphoblastoid cell line, MYA-1 cells, two types of lymphocyte-specific monoclonal antibodies (mAbs) were obtained. The 220/205/190 kd protein defined by 2F11 mAb is highly expressed on the surface of MYA-1 cells and another feline T lymphoma cell line, FL74 cells. The protein is also expressed on normal feline thymocytes, splenocytes and feline peripheral blood mononuclear cells (PBMCs). Another mAb, 17B10, caused similar results as those of 2F11 except for its low reactivity with FL74 cells. The second type of mAb, 15B3, defined the 220 kd protein. The reactivities of this mAb with MYA-1 cells, FL74 cells, PBMCs and feline splenocytes were lower than the former two mAbs, and did not react to feline thymocytes. On the other hand, 17B10 and 15B3 defined partial populations of MYA-1 and FL74 cells recognized by 2F11. The cells defined by the 2F11 and 17B10 are all leukocytes in spleen and lymph node. In contrast, 15B3 defined most of the cells in B cell area and partially in T cell area. These results suggested that 2F11 and 17B10 recognized the specific antigen of 220/205/190 kd of the leukocyte-common antigen (L-CA) family, CD45R, with different epitopes, and that 15B3 defined the distinct antigen of 220 kd on CD45R.

Animals↗