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Biomedical subjects

K Tani

Publications and source records attributed to K Tani.

At least 55 records · Page 3Linked to original sources
PubMed2001

Hydrocephalus and syringomyelia in a cat.

A 3-month-old male Japanese cat with feline parvovirus infection, showing central and cervical nerve abnormalities, was diagnosed as hydrocephalus and syringomyelia by use of magnetic resonance imaging (MRI). The cat was maintained clinically by medical treatment even though he could not stand. The MRI scans obtained about 5 months later showed that the ventricles had increased in size and the cervical syrinx had extended into the thoracic spinal cord. Ventriculoperitoneal (VP) shunt was performed. One week after surgery, neurological conditions had improved. At the postoperative MR images, the ventricles had decreased in size and the syrinx in the cervical and thoracic spinal cord could no longer be seen. The cat was still alive and was able to walk well.

Animals↗
PubMed2001

Thrombin promotes fibroblast proliferation during the early stages of experimental radiation pneumonitis.

Huang, L., Ogushi, F., Tani, K., Ogawa, H., Kawano, T., Endo, T., Izumi, K., Ueno, J., Nishitani, H. and Sone, S. Thrombin Promotes Fibroblast Proliferation during the Early Stages of Experimental Radiation Pneumonitis. Radiat. Res. 156, 45-52 (2001). To clarify the role of thrombin in the pathogenesis of radiation-induced pneumonitis, we measured the thrombin activity and fibroblast growth-inducing activity in bronchoalveolar lavage fluid obtained from the irradiated lungs of rats at 1, 2, 4, 8 and 18 weeks after irradiation. Thrombin activity was not detected in the bronchoalveolar lavage fluid from unirradiated rats, but the bronchoalveolar lavage fluid from irradiated rats showed significantly increased thrombin activity which reached a maximum at 4 weeks after treatment. Higher fibroblast growth-inducing activity was detected in the bronchoalveolar lavage fluid from irradiated rats at 4 and 18 weeks than in fluid from unirradiated rats. Bronchoalveolar lavage fluid from irradiated rats that were pretreated with the thrombin inhibitors antithrombin III and argatroban showed significantly inhibited fibroblast growth-inducing activity and thrombin activity at 4 weeks. However, these thrombin inhibitors did not inhibit fibroblast growth-inducing activity in bronchoalveolar lavage fluid from irradiated rats at 18 weeks. Purified rat thrombin similarly induced proliferation of fibroblasts derived from irradiated and unirradiated rats. These findings suggest that thrombin may play an important role as a fibroblast growth-inducing factor during the early stages of radiation pneumonitis.

Animals↗
PubMed2001

Flow-through chemiluminescence sensor using immobilized oxidases for the selective determination of L-glutamate in a flow-injection system.

A selective and sensitive chemiluminometric flow sensor for the determination of L-glutamate in serum, based on immobilized oxidases such as glutamate oxidase (GOD), uricase (UC) and peroxidase (POD), is described herein. The principle for the selective chemiluminometric detection for L-glutamate is based on coupled reactions of four sequentially aligned immobilized oxidases, UC/POD/GOD/POD in a flow cell. The immobilized UC was employed to decompose urate, which is one of the major interfering components in serum for a luminol-H2O2 chemiluminescence reaction. The H2O2 produced from the UC reaction readily reacted with reducing components, such as ascorbate and glutathione, and then the excess H2O2 was decomposed by the immobilized POD. L-Glutamate in the sample plug was enzymatically converted to H2O2 with immobilized GOD. Subsequently, the peroxide reacts with luminol on the immobilized POD to produce chemiluminescence, proportional to glutamate concentration. The enzymes were immobilized on tresylated poly(vinyl alcohol beads). The immobilized enzymes were packed into TPFE tube (1.0 mm i.d. x 60 cm), in turn, and used as a flow cell. The sampling rate was 30 h-1. The calibration graph for L-glutamate is linear for 20 nM-5 microM; the detection limit (signal-to-noise = 3) is 10 nM.

Ascorbic Acid↗
PubMed2001

Demethylation by 5-aza-2'-deoxycytidine (5-azadC) of p16INK4A gene results in downregulation of vascular endothelial growth factor expression in human lung cancer cell lines.

Vascular endothelial growth factor (VEGF) plays a pivotal role in tumor progression via angiogenesis. Recently, gene transduction of wild-type p16INK4A, tumor suppressor gene, has been shown to result in downregulation of VEGF expression in p16INK4A-deleted glioma cells. Because expression of p16INK4A is regulated by methylation of the p16INK4A gene, we examined whether demethylation of the p16INK4A gene by 5-aza-2'-deoxycytidine (5-azadC) could cause the protein expression of VEGF as well as of p16INK4A in human lung cancer cells. For this, five different lung cancer cell lines with or without loss of p16 activity were used. H841 and Ma-10 cells had the methylated p16INK4A gene without expression of p16INK4A protein, whereas Ma-1 and H209 cells had the unmethylated p16INK4A gene with constitutive expression of p16INK4A protein. Neither the p16INK4A gene nor p16INK4A protein was detected in A549 cells. Treatment with 5-azadC caused demethylation of the p16INK4A gene with reexpression of p16INK4A protein in H841 and Ma-10 (methylated p16INK4A gene dominant) cell, but not in other cell lines such as Ma-1, H209 (unmethylated p16INK4A gene dominant), or A549 (p16INK4A gene deleted). In a parallel experiment, 5-azadC inhibited production of VEGF protein by H841 and Ma-10 cells, especially in the later hypermethylated cells, but not Ma-1, H209, or A549 cells. RT-PCR analysis showed that Ma-10 cells expressed VEGF isoforms 121, 165, and 189, all of which were inhibited by 5-azadC. These findings indicate that the methylation status of the p16INK4A gene plays an important role in the regulation of angiogenesis associated with progression of lung cancer, through regulation of VEGF expression.

Antimetabolites, Antineoplastic↗
PubMed2001

Transatrial repair of ventricular septal rupture under preoperative localization by transesophageal echocardiography.

We report about a 71-year-old woman with postinfarction ventricular septal rupture who was successfully treated by the transatrial closure under preoperative localization by transesophageal echocardiography. In an attempt at transatrial repair of the ventricular septal rupture, the most important thing is preoperative localization of the defect in the septum, which is located high and posterior, where it is smooth with relatively few trabeculations and can be readily exposed by retraction of the tricuspid valve.

Aged↗
PubMed2001

A novel bioactive 31-amino acid endothelin-1 is a potent chemotactic peptide for human neutrophils and monocytes.

Endothelin (ET)-1(1-31) is a novel 31-amino acid-length peptide derived from big ET-1 by chymase or other chymotrypsin-type proteases and is a major ET derivative in human neutrophils. In this study, we revealed that ET-1(1-31), but not big ET, exhibited chemotactic activities toward human neutrophils and monocytes as an inflammatory mediator, although the effects were less potent than those of formyl-methionyl-leucyl-phenylalanine or interleukin-8. However, the chemotactic effects of ET-1(1-31) were much greater than those of the 21-amino acid ET-1, ET-1(1-21). Checkerboard analyses revealed that the effects are chemotactic rather than chemokinetic. The effects of ET-1(1-31) are not mediated by interleukin-8 or monocyte chemoattractant protein-1. The chemotactic effects and an increase in intracellular-free Ca(2)(+) caused by ET-1(1-31) were significantly inhibited by BQ123, an ET(A) receptor antagonist, but not by BQ788, an ET(B) receptor antagonist, suggesting that ET-1(1-31) mediates chemotaxis through an ET(A) or ET(A)-like receptor.

Calcium↗
PubMed2001

Protease-induced leukocyte chemotaxis and activation: roles in host defense and inflammation.

The migration of leukocytes such as neutrophils, monocytes and lymphocytes into inflamed lesions is one of the critical events of inflammation. Although the traditional function of neutrophil-derived antimicrobial proteases is to ingest and kill bacteria, some neutrophil serine proteases have been shown to induce leukocyte migration and activation. Mast cell-derived chymase also has the chemotactic activity for leukocytes. During the acute phase of inflammatory and allergic diseases, the predominantly migrated cells are neutrophils and mast cells, respectively, and in the subsequent chronic phase, monocytes and lymphocytes are mainly migrated. The chemotactic activity for monocytes and lymphocytes of neutrophil-derived serine proteases and mast cell-derived chymase may have a role in switching acute inflammation to chronic inflammation and delayed-type hypersensitivity. Recently, aminopeptidase N and endothelin were shown to induce chemotactic migration of leukocytes. Thus, protease-induced leukocyte chemotaxis and activation may play an important role in immunologic events of inflammatory and allergic diseases.

Antimicrobial Cationic Peptides↗
PubMed2001

Autoantibodies to IL-1 alpha in sera from rapidly progressive idiopathic pulmonary fibrosis.

To clarify the clinical significance of autoantibodies to interleukin-1 alpha (IL-1 alpha autoantibodies) in rapidly progressive idiopathic pulmonary fibrosis (IPF), we measured the level of IL-1 alpha autoantibodies in serum of 11 patients on the first hospital day, when patients were admitted due to severe symptoms, and on the 21st hospital day. IL-1 alpha autoantibodies in serum were measured using radioimmunoassay, and the limitation of this assay for IL-1 alpha autoantibodies was 5 ng/ml. These antibodies were detected in 5 of 11 patients on the first hospital day. On the 21st hospital day, these antibodies were detected in all patients, and its level was increased compared with that on the first hospital day. IL-1 alpha autoantibodies that appeared in patients corresponded to that of IgG. The half life of exogenous autoantibodies was investigated following administration of autoantibody rich plasma obtained from healthy blood donors to 6 control patients (CP) and 6 progressive IPF patients. These autoantibody levels in their serum were less than 5 ng/ml before administration. Serum was obtained at the indicated time after administration of IL-1 alpha autoantibodies and the level of these autoantibodies in serum was measured, then the half life was calculated. Half life of exogenous IL-1 alpha autoantibodies in progressive IPF patients was significantly shorter than that in CP (71.3 +/- 31.8 hr vs 352.0 +/- 98.3 hr, p < 0.01). These findings suggested that IL-1 alpha autoantibodies were generated in response to the inflammatory process of rapidly progressive IPF and may act as a regulatory factor for IL-1 alpha.

Aged↗
PubMed2001

Increased CCR4 expression in active systemic lupus erythematosus.

CC chemokine receptor (CCR)4 is selectively expressed on Th2-type T cells and has been shown to be responsible for Th2-dominant immune responses. In this study, we analyzed the expression of CCR4 in active systemic lupus erythematosus (SLE) patients by FACS analysis using anti-human CCR4 monoclonal antibody and determined the clinical relevance in this disease. Higher expression of CCR4 was found on peripheral blood CD4+ T lymphocytes of active SLE patients than was found with healthy controls and inactive SLE patients. The CCR4 expression significantly correlated with the SLE disease activity index (SLEDAI) scores. The expression was dramatically decreased after the corticosteroid therapy in parallel with a serum level of double-stranded DNA antibody and SLEDAI scores. Moreover, we found that serum levels of IL-10 were increased in active SLE patients and significantly correlated with the CCR4 expression. This study suggests that Th2 immune response is predominant in the active state of SLE, and CCR4 may have relevance in regard to the disease course in SLE patients.

Adolescent↗
PubMed2001

[Target therapy for CML--applying maxizyme].

Hammerhead type ribozyme, which have been frequently used for the purpose of specifically cleaving RNA at the GUC triplets in the experimental setting, can not be generally applicable for the gene therapy of leukemia with gene translocation. This is because the translocated sequence does not necessarily have the GUC triplets at the site of translocation. The introduction of new strategy which can specifically digest the chimera gene is considered to open new leukemia therapy with gene translocation. Maxizyme, a newly developed heterodimeric shortened ribozymes, can theoretically digest any types of chimeric genes at the site of translocation. In this review, our interesting results suggested the possible application of this maxizyme system for the treatment of chronic myelogenous leukemia with bcr/abl gene translocation.

Animals↗
PubMed2000

Determination of functional regions of p125, a novel mammalian Sec23p-interacting protein.

The Sec23p-Sec24p complex is a component of coat protein II-coated vesicles involved in protein export from the endoplasmic reticulum. We previously identified a novel Sec23p-interacting protein, p125, which consists of 1000 amino acids and comprises a proline-rich region and a phospholipase A(1) homology region. p125, when ectopically expressed in cultured cells, localizes to endoplasmic reticulum-Golgi intermediate regions. In the present study we showed that expressed p125 principally colocalizes with p115 and GM130, both of which are involved in vesicle tethering to Golgi membranes. Next, we determined the functional regions of p125 by expressing a p125 series with deletions. The results showed that the proline-rich region (residues 135-259) is responsible for the binding to Sec23p. For the correct localization of p125, a region (residues 135-1000) comprising both the proline-rich and phospholipase A(1) homology regions was required.

Animals↗
PubMed2000

N-ethylmaleimide-sensitive factor is associated with the nuclear envelope.

N-Ethylmaleimide-sensitive factor (NSF) is an ATPase involved in many membrane fusion events within the exocytic and endocytotic pathways. In the present study we showed that NSF is associated with the nuclear envelope. Golgi-associated NSF was released from membranes upon incubation with Mg(2+)-ATP, reflecting the disassembly of a complex consisting of NSF, soluble NSF attachment proteins (SNAPs), and SNAP receptors (SNAREs). In contrast nuclear envelope-associated NSF in interphase cells was not released by the same treatment. During mitosis, however, it was released from nuclear membranes by Mg(2+)-ATP. These results suggest that the binding mode of nuclear membrane-associated NSF changes during the cell cycle.

Adenosine Triphosphate↗
PubMed2000

Hyperfunction of neutrophils in a patient with BCR/ABL negative chronic myeloid leukemia: a case report with in vitro studies.

BACKGROUND: Among patients diagnosed with chronic myeloid leukemia (CML), a small percentage lack a BCR/ABL fusion gene, a landmark of CML. Their clinical features are distinct from patients with BCR/ABL positive CML, although to the authors' knowledge the pathogenesis to date has been unknown. METHODS: A 50-year-old female patient with BCR/ABL negative CML and multiple complications of Graves disease, Sweet syndrome, and a fatal pulmonary alveolar proteinosis (PAP) is described in the current study. To show a clonal origin of her myeloid cells, hypoxanthine phosphoribosyltransferase (HPRT) assay was applied. Because the patient developed a progressive and fatal neutrophilia, a screening of cell functions in neutrophilic lineage, including in vitro colony assay of her bone marrow cells and production of superoxide and interleukin-8 (IL-8) by blood neutrophils was performed. RESULTS: Southern blot analysis based on the polymorphism of the HPRT gene was compatible with monoclonality of her neutrophils. The patient had an increased amount of bone marrow granulocyte-macrophage progenitor cells, which formed colonies in response to a very low dose (0.1 ng/mL) of granulocyte-colony stimulating factor. In vitro production of superoxide and IL-8, which is an inducer of positive chemotaxis of neutrophils, by her peripheral neutrophils was markedly augmented. Her bronchoalveolar lavage fluid also contained a significant amount of IL-8 as well as an unusual infiltration of neutrophils. CONCLUSIONS: In the patient in the current study, hyperfunction of the neutrophils might have contributed to the onset of PAP as well as Sweet syndrome and to the pathogenesis of BCR/ABL negative CML.

Bone Marrow↗
PubMed2000

Poly(allylamine) beads as selective sorbent for preconcentration of formaldehyde and acetaldehyde in high-performance liquid chromatographic analysis.

Formaldehyde and acetaldehyde in water were determined by preconcentration with poly(allylamine) beads, derivatization with 2,4-dinitrophenylhydrazine (DPH) and analysis by HPLC. Poly(allylamine) beads (0.5 g) were used to adsorb formaldehyde and acetaldehyde at 1.2-150 microg l(-1) and 3.5-220 microg l(-1) from water (1 l). The concentration factor is 50 fold. The aldehydes were eluted and derivatized with 2 mM DPH in 0.5 M H2SO4 (10 ml). The time of analysis was 1 h. The detection limits (S/N=3) for formaldehyde and acetaldehyde were 0.6 and 2 microg l(-1), respectively.

Acetaldehyde↗
PubMed2000

Synthesis of macrocyclic cage compounds by diamine-dihalide one-step coupling reaction

Macropolycyclic cage compounds were synthesized by a direct reaction between diamines and bis(bromomethyl) compounds. The procedure for constructing the polycyclic cage structure is simple and straightforward. The macropolycyclic compounds obtainable from this cyclization procedure are three-dimensional cage compounds, and any other isomers were not obtained except for two examples. Benzene, pyridine, and aliphatic units could be introduced into the cage structure. The macrocycles that have strong cation affinity were obtained as their potassium complexes.

Journal Article↗