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Biomedical subjects

I Miyoshi

Publications and source records attributed to I Miyoshi.

At least 145 records · Page 8Linked to original sources
PubMed1992

Immunoglobulin prophylaxis against HTLV-I in a rabbit model.

We have investigated the protective effect of human T-cell leukemia virus I (HTLV-I) immune globulin (HTLVIG) against HTLV-I in rabbits. HTLVIG containing 77 mg/ml of IgG was prepared from pooled plasma from seropositive healthy persons. In the first experiment, four groups (A, B, C, and D) of three rabbits were transfused with 5 ml blood from an HTLV-I-infected rabbit. Groups A, B, and C were infused 24 h later with 10, 5, and 2 ml HTLVIG, respectively, while group D was infused with 10 ml HTLVIG 48 h later. Seroconversion for HTLV-I occurred in none of group A, one of group B, and all of groups C and D after 2-5 weeks. In the second experiment, four litters (E, F, G, and H) born to another virus-infected rabbit and consisting of 7, 5, 7, and 7 newborns, respectively, were used. Litters E and H were allowed to grow normally as controls, while litters F and G were given intraperitoneal inoculation of 3 ml/kg of HTLVIG weekly four times until weaning. Although three of litters E and H each seroconverted after 5-8 weeks, none of litters F, and one of litter G became antibody-positive after 10 weeks. Presence or absence of HTLV-I infection in all these animals was confirmed by transfusion assay or gene amplification. These results indicate that passive immunization protects rabbits against blood- and milk-borne transmission of HTLV-I.

Animals↗
PubMed1992

Effects of sex hormones on fulminant hepatitis in LEC rats: a model of Wilson's disease.

LEC rats, which have hereditary hepatitis and have recently been proposed as an animal model for Wilson's disease, were examined to determine the effects of sex hormones on fulminant hepatitis. After the rats had undergone ovariectomies or orchidectomies (castration) and were compared with intact rats, the age at the onset of fulminant hepatitis was not substantially altered but the survival rates decreased from 50% to 12.5% for females and 75% to 14.3% for males, indicating that sex hormones did not influence the occurrence of fulminant hepatitis but influenced mortality due to fulminant hepatitis. When testosterone was administered to the ovariectomized or orchidectomized rats, the survival rate increased to over 90% in both sexes. In contrast, estradiol did not affect the survival rate of either sex but affected the onset of fulminant hepatitis. That is, with the administration of estradiol, the age at which serum GPT activity reached its maximum was delayed 4 weeks in ovariectomized rats and 6 weeks in orchidectomized rats as compared with intact rats. A similar but somewhat weaker tendency appeared in rats given progesterone. The results of our study indicate that sex hormones have no effect on the rate of occurrence of hepatitis but affect the progression of hepatitis. In particular, testosterone increased the survival rate of rats with fulminant hepatitis, and exogenous estradiol delayed the onset of hepatitis for several weeks.

Alanine Transaminase↗
PubMed1992

Gene rearrangement and overexpression of PRAD1 in lymphoid malignancy with t(11;14)(q13;q32) translocation.

The proto-oncogene PRAD1 (parathyroid adenoma 1) on chromosome 11q13 was found to be overexpressed in all five B-cell lines with t(11;14)(q13;q32) translocation tested. One B-cell lymphoma and four myeloma cell lines with this translocation demonstrated more than 10-fold overexpression as determined by Northern blot analysis, when compared with normal lymphoid tissues such as thymus, spleen and lymph node. Hematopoietic cell lines without the translocation were also examined, but none of these demonstrated the overexpression, confirming that overexpression of the PRAD1 gene is associated with t(11;14) translocation. A truncated form of mRNA was seen in one of five cell lines with the translocation, SP-49. Hybridization with different regions of the PRAD1 cDNA revealed that the truncated form of mRNA retained the coding region but had lost the 3' untranslated region. Southern blot analysis demonstrated a gene rearrangement in this SP-49 cell line. To study the genetic alteration responsible for the truncated form of mRNA in this cell line, the rearranged allele as well as the germline allele were cloned. The restriction map revealed that the rearranged portion was at the 3' end of the PRAD1 gene, eliminating the mRNA-destabilizing signal AUUUA. Human-rodent hybrid cell analysis demonstrated that the region introduced 3' of PRAD1 was derived from chromosome 11, suggesting that the PRAD1 gene region is deleted at the 3' end. Over-expression of the PRAD1 gene in association with t(11;14)(q13;q32) translocation suggested that in these cases the regulation of PRAD1 was altered by the juxtaposed gene, most likely the immunoglobulin heavy-chain gene from chromosome 14.

Base Sequence↗
PubMed1992

Acute megakaryoblastic leukemia: establishment of a new cell line (MKPL-1) in vitro and in vivo.

A megakaryoblastic cell line (MKPL-1) was newly established from the bone marrow of an adult patient with acute megakaryoblastic leukemia. This cell line grew in single cell suspension with a doubling time of 30 h and consisted of large primitive blasts with persistent development of giant cells carrying multilobed nuclei. MKPL-1 cells were positive for platelet GPIIb/IIIa (CD41) and GPIIIa (CD61), and expressed OKM5 (CD36), MY7 (CD13), and MY9 (CD33) antigens in the absence of erythroid and lymphoid markers. The cytochemical and morphologic characteristics of MKPL-1 were also consistent with those of megakaryoblasts. The cells did not, however, express ultrastructural platelet peroxidase which is considered to be another marker of the megakaryocytic lineage. Cytogenetic analysis of MKPL-1 revealed a model chromosome number of 92 with abnormal chromosomes including those found in the patient's bone marrow cells. Furthermore, MKPL-1 cells were serially transplanted into nude mice for nine passages with production of lethal tumors and leukemic manifestation. Thus, our megakaryoblastic cell line which can be maintained both in vitro and in vivo would be useful for further studies of the biology of megakaryopoiesis and megakaryoblastic leukemia.

Aged↗
PubMed1991

Adult T-cell leukemia: structures and expression of the p53 gene.

Experiments were undertaken to investigate a genetic event involved in leukemogenesis in adult T-cell leukemia (ATL). For this purpose, the p53 gene was chosen for study, since alteration of the gene has been found in a wide variety of human cancers. Structures and expression of the p53 gene in ATL cells were investigated by Southern and Northern blot analyses and a polymerase-chain-reaction single-strand conformation-polymorphism (PCR-SSCP) analysis. Either subtle alterations of the p53 gene or the absence of detectable level of p53 mRNA were found in 2 of 3 acute ATL cell lines and 2 of 12 acute ATL fresh samples. In contrast, no mutation was detected in 4 cases with less aggressive types of ATL (3 chronic and 1 smoldering ATL cases). Mutations found in acute ATL cells occurred in regions highly conserved in evolution and all the cells carrying p53 mutation showed loss of the other p53 allele. These results suggests that alteration of the p53 gene may contribute to progression of the disease in some cases of ATL.

Adult↗
PubMed1991

Dexamethasone and phorbol ester, but not cytokines, increase the production of plasminogen activator inhibitor type-2 in the PL-21 human promyelocytic leukemia cell line.

PL-21 is a promyelocytic leukemia cell line that produces plasminogen activator inhibitor 2 (PAI-2). Differentiation-linked expression of PAI-2 was investigated by adding cell-differentiation promoting agents [such as phorbol myristate acetate (PMA), retinoic acid (RA), dexamethasone (Dex), and recombinant cytokines, including tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta), granulocyte-colony stimulating factor (G-CSF), and interleukin-6 (IL-6)] into the culture medium of PL-21 cells. PAI-1 and PAI-2 antigens were measured by an enzyme-linked immunoassay. The PAI-1 antigen, however, became detectable only after stimulation. The presence of PAI-2 antigen was further verified by immunoblotting using a monoclonal antibody against PAI-2 purified from a PL-21 culture medium. PAI activity both in the culture medium and in the cell lysate increased approximately 70-fold after exposure to PMA. Both PAI-1 and PAI-2 antigens increased, but the amount of the latter in the culture medium and in the cell lysate was approximately 10 times and 2,500 times, as much, respectively, as that of the former. Dex also increased the intracellular PAI activity approximately 6-fold, parallel with PAI-2 antigen. PAI-1 antigen increased only slightly in the culture medium but not in the cell lysate after Dex-stimulation. As with the case of PMA, TNF-alpha and IL-6 induced PL-21 cells to macrophage-like cells, but did not affect the PAI activity. Thus, the increase of the PAI-2 production by PMA may not necessarily depend on differentiation into macrophages. Other cytokines examined did not increase the PAI activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytokines↗
PubMed1991

Novel t(15;19)(q15;p13) chromosome abnormality in a thymic carcinoma.

A 22-year-old female with a thymic carcinoma is reported. The tumor was refractory to both chemotherapy and irradiation. The patient died with an aggressive clinical course. Cytogenetic study showed that the tumor cells had a chromosome translocation, t(15;19)(q15;p13), which was not identified previously in human cancer.

Adult↗
PubMed1991

In vitro immunization of rat spleen lymphocytes with Forssman glycosphingolipid antigen and the generation of a monoclonal antibody.

A procedure for in vitro immunization of splenic lymphocytes with a glycolipid antigen is described. Culture medium supernatant of ConA- and PHA-stimulated spleen cells and that of Con A-stimulated human Jurkat T cell line (IL-2-rich medium) were used as sources of cytokines to support T and B cell stimulation, and anti-mu was used to support B cell differentiation. Unprimed rat spleen cells (2 x 10(6)/ml) were stimulated with 2 micrograms/ml Forssman glycolipid antigen coupled to Sepharose for 4 days. The cells were fused with a mouse myeloma cell line P3-X63-Ag8-U1. At initial screening, 12% of the colony forming wells were secreting specific antibody. After cloning, a stable hybridoma cell line (designated 4C3) was established which secreted a monoclonal IgM antibody directed against the carbohydrate moiety of Forssman glycosphingolipid (GalNAc alpha 1-3GalNAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc-ceramide).

Animals↗
PubMed1991

Molecular cloning of the chromosomal breakpoint of a B-cell lymphoma with the t(11;14)(q23;q32) translocation.

The breakpoint of t(11;14)(q23;q32) chromosome translocation in a B-cell lymphoma line, RC-K8, was cloned. Immunoglobulin heavy chain (IGH) constant gene, C gamma 2 at the 5' end, was involved in this translocation, and the DNA segment juxtaposed to the C gamma 2 was proved to be derived from chromosome 11 by somatic cell hybrid study. The normal counterpart of chromosome 11 was also isolated. With a DNA probe near the breakpoint of chromosome 11, Southern blot analysis of RC-K8 and 10 other cases with translocation involving the 11q23 region was conducted, but no rearrangement bands have been observed thus far except for RC-K8.

Base Sequence↗
PubMed1991

Establishment of a new Epstein-Barr virus nuclear antigen-positive B-cell line, BALL-2, with t(8;14) (q24;q32) chromosome abnormality from B-cell acute lymphoblastic leukemia, L2.

A new Epstein-Barr virus nuclear antigen (EBNA)-positive B-cell line, designated BALL-2, was spontaneously established from the peripheral blood of a 14-year-old boy with an EBNA-negative B-cell acute lymphoblastic leukemia (B-ALL), L2 in the French-American-British classification. The BALL-2 cell line grew in suspension with or without forming clumps of cells. The cultured cells exhibited lymphoid morphology with indented or lobulated nuclei, prominent nucleoli, and relatively abundant cytoplasm. Immunologic and cytogenetic studies showed that the BALL-2 cell line expressed the B-cell phenotype, CpIg+, SmIg+, CD19+, CD20+, CD38-, Ia+, and had chromosome translocation, t(8;14) (q24;q32). The same phenotypic and chromosome markers were present in original leukemia cells. These results indicated that the cell line was derived from the patient's leukemia cells. Unexpectedly, however, BALL-2 cells were positive for EBNA and EB virus DNA. Gene analysis of the BALL-2 cell line showed biallelic rearrangements in the JH locus. One of the JH rearrangement comigrated with a rearranged c-myc gene, indicating the translocation had occurred between JH and c-myc loci. The t(8;14) abnormality is a known chromosome marker of Burkitt lymphoma and L3 type ALL. Our studies revealed that this translocation and myc gene rearrangement can also be found in L2 type B-ALL.

Adolescent↗
PubMed1991

Characterization of two human lymphoid cell lines producing human T-lymphotropic virus type I (HTLV-I) isolated from patients with HTLV-I-associated myelopathy or encephalopathy.

Two cell lines, CNS-5 and CNS-6, were established by cocultivation of sedimented cells in cerebrospinal fluid (CSF) from two anti-human T-lymphotropic virus type I (HTLV-I) antibody-positive male patients with encephalopathy and HTLV-I-associated myelopathy, respectively, with peripheral blood mononuclear cells from a healthy seronegative female. These cell lines, possessing a normal female karyotype, revealed similar characteristics as follows; they expressed HTLV-I-related antigens, they produced C-type retrovirus particles, HTLV-I provirus genomes were integrated into their DNAs, and they had CD4+ activated T-cell markers. In addition, immunocytochemical and immunoelectron microscopic studies showed peculiar immunoreactivity of these cell lines with anti-alpha/beta T-cell antigen receptor (TCR) antibodies; beta Fl, defining beta chain epitope, was only positive in the perinuclear spaces and rough endoplasmic reticulum in some cells, and WT31, recognizing alpha/beta framework, was mostly negative, while CD3 was expressed in the majority of the cells. These facts indicate that HTLV-I-infected cells were present in CSF of these two patients, and suggest that neurological disorders associated with HTLV-I may not be restricted to myelopathy and may include brain abnormalities.

Aged↗
PubMed1991

A new monoclonal antibody to human subcapsular thymic epithelial cells.

A monoclonal antibody, termed K-20, was generated against an anaplastic thymic carcinoma cell line, Ty-82. Subcapsular thymic epithelial cells of the thymus and blood vessels in various organs were shown to react with the K-20 monoclonal antibody by immunohistochemical staining. Immunofluorescent study revealed that various haematopoietic fresh cells and cell lines did not show any significant reactivity with K-20, except for one Epstein-Barr-virus-carrying lymphoma cell line (SP-50B). Western immunoblotting and affinity purification procedure revealed that K-20 was directed to a protein with a molecular weight of 28 kDa. K-20 is unique in its restrictive reactivity with human subcapsular thymic epithelial cells.

Antibodies, Monoclonal↗
PubMed1991

D-factor: modulation of expression in fibroblasts.

Differentiation inducing factor (D-factor) is a recently described protein. The gene has been cloned, but little is known concerning regulation of expression of the gene. Our study showed that fibroblasts from a variety of tissues (lung, bone marrow, gingiva, foreskin) constitutively expressed D-factor RNA. Levels of expression of this gene increased in fibroblasts of each of the tissues after exposure to several stimuli including products of activated macrophages and lymphocytes (tumor necrosis factor (TNF), interleukin 1 and lymphotoxin). Other stimuli were those capable of activating either protein kinase C (12-O-tetradecanoylphorbol-13-acetate (TPA) and teleocidin), G-binding proteins (NaF) or those inhibiting protein synthesis (cycloheximide). Accumulation of D-factor RNA by TNF may in part be explained by stabilization of D-factor transcripts; TPA and cycloheximide clearly stabilized D-factor transcripts. We and others have shown that these same signals similarly stimulated fibroblasts to express RNAs coding for a variety of cytokines including three colony-stimulating factors as well as interleukins 1 and 6. Taken together, D-factor probably is a participant in the cascade of cytokines that are produced in mesenchymal cells after various stimuli such as bacterial invasion.

Cells, Cultured↗
PubMed1991

Immunoglobulin prophylaxis against milkborne transmission of human T cell leukemia virus type I in rabbits.

Prophylactic effect of human T cell leukemia virus type I (HTLV-I) immune globulin (HTLVIG) against milkborne transmission of HTLV-I was investigated in a rabbit model. Four litters (A-D: 7, 5, 7, and 7 offspring, respectively) born to an HTLV-I-infected rabbit were used. Litters A and D were allowed to grow normally as controls, while litters B and C were given weekly intraperitoneal inoculation of HTLVIG four times until weaning at 4.5 weeks of age. Only 1 (8.3%) of the 12 HTLVIG-inoculated rabbits, compared with 6 (42.9%) of the 14 control rabbits, seroconverted for HTLV-I. Gene amplification detected the presence of HTLV-I proviral sequences in all of the seroconverted but in none of the seronegative rabbits. These results suggest that passive immunization is effective in preventing dam-to-offspring transmission of HTLV-I.

Animals↗
PubMed1991

Single cilium in human leukemic cells heterotransplanted into hamsters.

Single cilium formation was studied in two human hematopoietic cell lines, KCL-22 and MT-2, KCL-22, established from a patient with chronic myelogenous leukemia in blastic crisis, and MT-2, a human cord T cell line carrying human T-lymphotropic virus type I, were transplanted into hamsters. Ciliogenesis was observed in both cell lines, only after transplantation into hamsters.

Animals↗
PubMed1991

Changes in Cu,Zn-superoxide dismutase gene during induced erythroid and myeloid differentiation.

We investigated the alteration of Cu,Zn-superoxide dismutase during erythroid and myeloid differentiation in order to elucidate its physiological significance in different types of cells. We measured enzyme activity and mRNA levels of superoxide dismutase in the process of differentiation to erythroid cells or myeloid cells. When human leukemia K562 cells are incubated in the presence of 80 microM hemin, benzidine-positive cells appear on day 1 and 80% of the cells become positive on day 5. During hemin-induced erythroid differentiation, Cu,Zn-superoxide dismutase activity increases 3.5-fold of the initial value and mRNA for Cu,Zn-superoxide dismutase increases prior to the activity to the same extent. On the other hand, when human promyelocytic leukemia HL-60 cells are incubated in the presence of 1.3% dimethyl sulfoxide, nitroblue tetrazolium-positive cells reach approximately 90% on day 5. During dimethyl sulfoxide-induced myeloid differentiation, the activity of Cu,Zn-superoxide dismutase decreases below 15% of the initial value on day 5 and mRNA for Cu,Zn-superoxide dismutase decreases as well. The results indicate that the synthesis of superoxide dismutase is linked with either the erythroid or myeloid differentiation program.

Blotting, Southern↗
PubMed1991

[Characterization of the factor VIII inhibitor in a patient with chronic renal failure].

A 29-year-old women, who had been treated by hemodialysis for 5 years because of chronic renal failure, developed bleeding tendency in March 1989. Laboratory data showed prolonged activated partial thromboplastin time which was not corrected by addition of normal plasma; factor VIII activity was less than 1% and factor VIII inhibitor 70 Bethesda units/ml. The inhibitor was eluted in the second peak which corresponded to IgG when the plasma was subjected to Sephacryl S 200 column. The further purified IgG fraction by passing through protein A column showed a factor VIII inhibitor activity of 52 Bethesda units/ml. The factor VIII inhibitor epitopes were examined by western blotting technique using factor VIII purified by monoclonal antibody as the antigen. The factor VIII preparation used was composed of a doublet of light chain (Mr 80,000) and three heavy chains (Mr 160,000-200,000) when examined by immunoblotting using anti-factor VIII light and heavy chains monoclonal antibodies after SDS-PAGE. Factor VIII inhibitor that arose in a hemophilia A patient recognized the light chain, and the inhibitor in this case reacted to the heavy chain of factor VIII.

Adult↗