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Biomedical subjects

T Ohno

Publications and source records attributed to T Ohno.

At least 433 records · Page 24Linked to original sources

[Aggressive transformation of an indolent myeloma with abdominal extramedullary plasmacytoma after 6-year period of observation].

62-year-old female, who had been under observation for an indolent myeloma for six years without therapy, was admitted because of left flank pain. Various imaging modalities disclosed left pleural effusion, and a huge abdominal tumor involving the left crus of the diaphragm, spleen, stomach, pancreatic tail, left adrenal gland, left kidney and left posterior abdominal wall. Morphological and immunological examinations revealed extensive proliferation of more anaplastic myeloma cells within the tumor and in the pleural effusion than those in bone marrow on admission or at the beginning of the period of observation. Chemotherapy reduced serum M-protein, but LDH, the volume of the pleural effusion, and the size of the tumor increased. She died of pancreatitis associated with massive bleeding from the gastric tumor. Renal function was well preserved until her terminal phase. The clinical course showed the progression of indolent myeloma into an aggressive one without chemotherapeutic intervention, implying a rare subtype in terms of the natural history of multiple myeloma.

Abdominal Neoplasms↗

[A progress in the diagnosis of malignant lymphoma].

Malignant lymphoma is usually divided into Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) according to the biological characteristics. Although the exact nature of HD is still unclear, NHL is well known to be a neoplasm of monoclonal and malignant B- or T-lymphocytes. Nowadays, the classification of pathologic type in HD seems to be settled in the Rye classification. On the other hand, in NHL the LSG classification has been fixed routinely in Japan and the Working Formulation originating in the USA has been used internationally after some historical confusion. As a recent trend in lymphoma diagnosis, the introduction of immunological and molecular biological techniques has had an impact on the previous concept and classification of malignant lymphoma based mainly on morphological criteria. In this article, recent progress in the diagnosis of malignant lymphoma, mainly NHL, including the analysis of immunophenotype and immunogenotype (intragenic and intergenic gene rearrangement) is briefly described.

Female↗

[Injury of the coronary artery following non-penetrating chest trauma--a case report].

A previously healthy 71-year-old man sustained a non-penetrating chest trauma. The chest CT scan revealed cardiac tamponade and then emergent operation was performed. We opened the pericardium through median sternotomy and found a laceration of the distal left anterior descending coronary artery (seg. 8). We ligated the artery and he showed signs of a limited myocardial infarction on the postoperative ECGs, but echocardiography revealed symmetric contraction and normal ejection fraction. His postoperative course was uneventful. We think that injuries of distal coronary arteries could be successfully ligated.

Aged↗

Direct transfer of plasmid DNA from intact yeast spheroplasts into plant protoplasts.

We developed a polyethylene glycol (PEG)-mediated direct DNA transfer method from intact Saccharomyces cerevisiae spheroplasts into Arabidopsis thaliana protoplasts. To monitor the DNA transfer from yeast to plant cells, beta-glucuronidase (GUS) reporter gene in which a plant intron was inserted was used as a reporter. This intron-GUS reporter gene on a 2 microns-based plasmid vector was not expressed in yeast transformants, while it expressed GUS activity when the plasmid DNA was introduced into plant cells. When a mixture of 1 x 10(8) of S. cerevisiae spheroplasts harboring the plasmid and 2 x 10(6) of A. thaliana protoplasts was treated with PEG and high pH-high Ca2+ solution (0.4 M mannitol, 50 mM CaCl2, 50 mM glycine-NaOH pH 10.5), GUS activity was detected in the extract of the plant cells after a three-day culture. The GUS activity was higher than that of a reconstitution experiment in which the mixture of 1 x 10(8) of S. cerevisiae spheroplasts which did not carry the reporter gene, 2 x 10(6) of A. thaliana protoplasts and the same amount of the reporter plasmid DNA as that contained in 1 x 10(8) of S. cerevisiae spheroplasts, was treated with PEG and high pH-high Ca2+ solution. Moreover, the GUS gene expression was resistant to micrococcal nuclease treatment before and during PEG treatment. From these results, we concluded that plasmid DNA can be directly transferred from intact yeast spheroplasts to plant protoplasts by a nuclease-resistant process, possibly by the cell fusion.

Arabidopsis↗

[Successful pregnancy after allogeneic bone marrow transplantation: two case reports].

A case of successful pregnancy after allogeneic bone marrow transplantation (BMT) in a woman with severe aplastic anemia conditioned with 200 mg/kg cyclophosphamide and 4.5 Gy total lymphoid irradiation (TLI) at the age of 15 years is reported. She delivered a normal child 92 months after BMT. A male with paroxysmal nocturnal hemoglobinuria received allogeneic BMT at the age of 22 years is described as a second case. He was conditioned with 200 mg/kg CY and 7.5 Gy TLI and parented a normal child 32 months after BMT. These observations demonstrate that normal pregnancy can follow high dose chemotherapy and TLI.

Adolescent↗

The EWS gene, involved in Ewing family of tumors, malignant melanoma of soft parts and desmoplastic small round cell tumors, codes for an RNA binding protein with novel regulatory domains.

The EWS gene, which maps to band q12 of human chromosome 22, is involved in a wide variety of human solid tumors including Ewing sarcoma, related primitive neuroectodermal tumors, malignant melanoma of soft parts and desmoplastic small round cell tumors. In these tumors, the EWS is fused to genes encoding transcriptional activators/repressors, like Fli-1 or erg or ATF 1 or wt1. To better understand the function of the EWS protein, we cloned the EWS cDNA. Sequence analysis of this cDNA revealed differential splicing involving two exons encoding 72 amino acids. Both alternatively spliced transcripts, EWS and EWS-b, are expressed in a variety of cells. Because EWS proteins contain putative conserved RNA binding motifs, we studied the RNA binding properties of the EWS protein. The EWS-b protein binds to RNA in vitro and, specifically, to poly G and poly U. The RNA binding activity was localized to the carboxy terminal 86 amino acids, which constitute RGG box. Thus the amino terminal domain of EWS (NTD-EWS), which is involved in chromosome translocation may regulate the specificity of RNA binding activity of EWS. An EWS-erg chimeric protein, which is found in Ewing's sarcoma cells, functions as a transcriptional activator. Mutational analysis of EWS-erg chimeric protein revealed that NTD-EWS functions as a regulatory domain for the transcriptional activation properties of EWS-erg chimeric protein.

Amino Acid Sequence↗

[Successful surgical treatment in a case of complete rupture of the posterior papillary muscle of the mitral valve caused by infective endocarditis].

Forty three year-old male who had cough and easy fatigability since three weeks prior to admission was diagnosed to have acute pulmonary edema with severe mitral regurgitation caused by active infective endocarditis. Transesophageal echocardiograms under the endotracheal intubation for controlled respiration suggested rupture of the posterior papillary muscle of the mitral valve and the emergency surgical treatment was performed. Intraoperatively the total rupture of the posterior papillary muscle was confirmed and mitral valve replacement was carried out with a SJM prosthetic valve. Histological examination of the ruptured papillary muscle revealed hemorrhage, muscle necrosis and small cell infiltration suggesting the presence of active inflammation with bacteria on it. Staphylococcus epidermidis was demonstrated by the bacteriological studies of the ruptured papillary muscle.

Adult↗

TESS line: a laboratory line of the musk shrew (Suncus murinus, Insectivora), triple-homozygous for the curly hair (ch), cream coat-color (cr) and red-eyed dilution (rd) genes and segregating the sucrase deficients (suc/suc).

The TESS line, the first tester line of the Suncus has been developed. The TESS shrews are homozygous for three morphological mutant genes, ch, cr and rd. The gene (suc) for sucrase activity deficiency in intestinal brush-border membranes also exists in the line, and its frequency was 34.3%. The deficients could easily be identified by the drastic body-weight losing up to more than 15% of the initial weight, that aroused two days after replacement of the drinking water for its 10%-sucrose solution. The TESS shrews have been maintained as a closed-colony consisting of more than 30 individuals, and will be utilized in linkage analysis with the four loci (ch, cr, rd and suc).

Animals↗

RES-701-1, a novel, potent, endothelin type B receptor-selective antagonist of microbial origin.

The unique cyclic peptide designated RES-701-1 blocked the binding of 125I-labeled endothelin (ET)-1 to bovine cerebellar membranes. ETB receptors are predominant in bovine cerebellum. However, in bovine lung membranes, where both ETA and ETB receptors are expressed, RES-701-1 inhibited 125I-ET-1 binding by up to 70%; RES-701-1, in the presence of the ETA-selective antagonist BQ-123 at 1 microM, displaced 125I-ET-1 binding completely. With membranes from transfected Chinese hamster ovary cells expressing the human ETA or ETB receptors, RES-701-1 inhibited 125I-ET-1 binding to the ETB receptor with an IC50 value of 10 nM but had no effect on 125I-ET-1 binding to the ETA receptor. Thus, RES-701-1 is highly specific for the ETB receptor; it has no effect on a number of other receptors. RES-701-1 selectively inhibited the ET-1-induced increase in intracellular Ca2+ concentration in COS-7 cells expressing the ETB receptor but did not inhibit the Ca2+ transient in ETA-expressing cells. When injected intravenously (250 nmol/kg) into anesthetized rats, RES-701-1 abolished the initial depressor response to ET-1 but enhanced the subsequent pressor response. These results suggest that RES-701-1 is a potent and specific antagonist for the ETB receptor and that RES-701-1 will be a powerful tool for understanding the physiological roles of this receptor.

Animals↗

EWS/Fli-1 chimeric protein is a transcriptional activator.

Fli-1, an ets related gene, was found to be rearranged in 75% of erythroleukemias induced by Friend murine leukemia virus. We have shown previously that the Fli-1 gene codes for a sequence specific transcriptional activator which contains two autonomous transcriptional activation domains, one at the amino terminal region and the other at the carboxy terminal region. Recently human Fli-1 gene was shown to be involved in Ewing's sarcoma and related subtypes of primitive neuroectodermal tumors which share t(11;22) (q24;q12) chromosome translocation. In these tumors the carboxyl terminal region of Fli-1 was found to be fused with the amino terminal region of a putative RNA binding protein, EWS. Because part of the amino terminal transcriptional activation domain of Fli-1 was replaced with the amino terminal domain of the EWS (NTD-EWS) which shares homology with RNA polymerase II, it was speculated that NTD-EWS may interfere with RNA pol II function. Alternatively, NTD-EWS could also contribute to the transcriptional activation function of EWS/Fli-1 chimeric protein by providing either a modulatory/regulatory domain or a novel transcriptional activation domain. Here we show that EWS/Fli-1 chimeric protein functions as a transcriptional activator. Deletion analysis reveals that the EWS domain functions as a modulatory/regulatory domain for the transcriptional activation properties of the carboxy terminal transcriptional activation domain of EWS/Fli-1. We therefore propose that replacement of the amino terminal transcriptional activation domain of the Fli-1 protein with the regulatory domain of NTD-EWS results in the activation of the carboxy terminal transcriptional activation domain of Fli-1 which may be the molecular mechanism involved in these human tumors.

3T3 Cells↗

Characterization of an IgM Fc-binding receptor on human T cells.

The existence of an IgM receptor on human T cells has been suggested by T cell rosetting with IgM-coated erythrocytes. In this study we used immunofluorocytometry to demonstrate that 1) after short-term culture, a majority of the T cells can bind IgM at easily detectable levels, 2) human and mouse IgM preparations bind to human T cells but other Ig isotypes do not, 3) the IgM binding is saturable and inhibitable only by Ig of IgM isotype and 4) the Fc portion of IgM is involved in the binding to a protease-sensitive cell surface protein. Biochemical analysis of the T cell receptor for IgM reveals a cell surface protein of 60 kDa in comparison with the 58 kDa Fc mu receptors (Fc mu R) on B-lineage cells. Although Fc mu R expression is up-regulated after B cell activation, the reverse is true after T cell activation. In addition, the T cell Fc mu R is relatively resistant to phospholipase C treatment. These results indicate that T- and B-lineage cells express Fc mu R with different biologic characteristics.

Animals↗

Discrepancy between biochemical and virological responses to interferon-alpha in chronic hepatitis C.

Serial serum samples and pretreatment and post-treatment liver tissue from patients with chronic hepatitis C virus (HCV) infection were tested for HCV RNA by reverse-transcription polymerase chain reaction and branched DNA signal amplification assays. At the end of treatment with interferon-alpha (IFN alpha), 4 of 5 patients showing no biochemical response (in alanine aminotransferase activity), 4 of 5 with transient responses, and 1 of 5 showing complete and sustained responses had HCV RNA detectable in serum. The corresponding numbers for liver tissue were 5, 5, and 0 (of 4). However, all 5 complete responders had virological relapses within 6 months. Biochemical response may not reflect virological profile during IFN alpha treatment of HCV.

Adult↗

Segregation of cerebrorubral and cerebellorubral synaptic inputs on rubrospinal neurons of fetal cats as demonstrated by intracellular recording.

Cerebrorubral and cerebellorubral inputs are localized to distal dendrites and somata of red nucleus neurons in adult cats, respectively. To examine if this segregation is established early in development, we performed intracellular recording from rubrospinal neurons of fetal cats aged from embryonic day 58 to 65. Stimulation of the contralateral cerebellar nuclei evoked excitatory postsynaptic potentials (EPSPs). EPSPs were also induced by stimulation of the ipsilateral pericruciate cortext but they were much slower in time course and smaller in amplitude compared to cerebellar ones. We suggest that cerebrorubral and cerebellorubral synapses are segregated on soma-dendritic membrane of rubrospinal neurons early in development.

Animals↗

Analysis of 6R- and 6S-tetrahydrobiopterin and other pterins by reversed-phase ion-pair liquid-chromatography with fluorimetric detection by post-column sodium nitrite oxidation.

A rapid and sensitive reversed-phase ion-pair liquid chromatographic system with fluorimetric detection by post-column sodium nitrite oxidation was established for measuring six pterin compounds (6R-5,6,7,8-tetrahydrobiopterin, 6S,5,6,7,8-tetrahydrobiopterin, 7,8-dihydrobiopterin, biopterin, pterin and D-neopterin). The coefficients of variation for these pterins were 0.705-3.714%, and the minimum detectable amount was ca. 10-20 pg at a signal-to-noise ratio of 3. A linear detector response was also verified. The concentrations of the pterin compounds in rat tissues were measured by the described method. Furthermore, by means of brain microdialysis, the output of pterin compounds from rat striatum was detected. Therefore, these results demonstrate that this system can be applied to analyses not only of various rat tissues but also of dialysates collected in vivo.

Animals↗

C-type natriuretic peptide inhibits intimal thickening after vascular injury.

Recently we have found that C-type natriuretic peptide (CNP) inhibits proliferation of cultured rat vascular smooth muscle cells through an elevation of cGMP. We have now tested whether administration of CNP inhibits the development of intimal lesions induced by air-drying injury in rat common carotid arteries in vivo. CNP treatment (1 microgram/kg/min, i.v. infusion) for either 14 or 5 days resulted in 70% or 60% reduction, respectively, of intimal cross-section area 14 days after injury as compared with control rats. We also found that CNP potently stimulated cGMP production in injured carotid arteries with intimal thickening, but not in intact ones. These results indicate that GC-B, CNP specific receptor/guanylyl cyclase, is expressed at the sites of vascular injury, and that CNP might be efficacious in the prevention of restenosis caused by intimal thickening following coronary angioplasty.

Animals↗

Mechanistic effects of kijimicin on inhibition of human immunodeficiency virus replication.

Kijimicin represents an important type of ionophore compound. In veterinary medicine, it is becoming important as anticoccidiostatic agent and feed supplement. We examined Kijimicin for its HIV inhibitory activity. The compound exhibited concentration-dependent inhibition of HIV replication in primary infected cultures of human T-lymphoblastoid H9 cells. Substantial inhibition of viral replication was observed at concentrations of Kijimicin that showed little cytotoxicity. The ratio of IC50 values for the MTT to RT assays was 40. Anti HIV activity was also observed in cultures of monocytic lineage U937 cells chronically infected with HIV. Moreover, in attempting to define the inhibitory mechanism of Kijimicin, we investigated its effect on each step of HIV replication. The infectivity of progeny viral particles was reduced by Kijimicin treatment. This decrease may be due to incompletely glycosylated forms of gp120.

Acquired Immunodeficiency Syndrome↗