526
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Sudo K, Konno K, Yokota T, Shigeta S. A sensitive assay system screening antiviral compounds against herpes simplex virus type 1 and type 2. J Virol Methods 1994; 49:169-78. [PMID: 7822458 DOI: 10.1016/0166-0934(94)90041-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A highly sensitive and accurate assay system was developed for in vitro evaluation of anti-herpes simplex virus (anti-HSV) agents using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and human embryonic lung fibroblast (MRC-5) cells. This assay system was found to be highly sensitive for both HSV-1 and -2. Confluent MRC-5 cells were infected with either HSV-1 KOS strain or HSV-2 G strain of 25 TCID50 in the presence of various concentrations of test compounds. The optical density of formazan was used to determine cell viability. The EC50 values of acyclovir and several other anti-HSV agents were found to be similar to those obtained by the plaque reduction method. These results indicate that this MTT assay is useful for screening anti-HSV-1 and -2 agents.
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527
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Chen JX, Watanabe S, Muto A, Miyajima A, Yokota T, Arai K. Activation of early response genes and cell proliferation by human interleukin-3, granulocyte-macrophage colony-stimulating factor, and interleukin-5 receptors: comparison with human interleukin-4 receptor signaling. J Allergy Clin Immunol 1994; 94:605-11. [PMID: 8083468 DOI: 10.1016/0091-6749(94)90136-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Interleukin (IL)-3, granulocyte-macrophage colony-stimulating factor, and IL-5 receptors (IL-3R, GMR, and IL-5R) are composed of the alpha chain specific to each and the common beta chain, and both the alpha and beta subunits are members of the cytokine receptor superfamily. We previously showed that the high-affinity human GMR reconstituted by cotransfecting the alpha and beta chain cDNA clones transduces signals in response to hGM-CSF to activate transcription of c-fos, c-jun, and c-myc proto-oncogenes in mouse proB cell line BA/F3 or in mouse fibroblast NIH3T3 cells. These results indicated that molecules, such as tyrosine kinase, unique to hematopoietic cells are not essential to transduce signals. In this study, the function of the alpha subunit of GMR was compared with those of IL-3R and IL-5R by cotransfecting human cDNAs encoding the alpha subunit of IL-3R or IL-5R and the common beta subunit into BA/F3 or NIH3T3 cells. We found that the reconstituted human IL-3R, in response to hIL-3, transduced signals to activate transcription of c-fos promoter and induced DNA synthesis in both types of cells in a manner similar to hGMR. Likewise, hIL-5 activates c-fos promoter in transfected NIH3T3 cells expressing hIL-5R. These results indicated that the alpha subunits of IL-3R and IL-5R have properties similar to those of the GMR alpha subunit. In contrast, transfected human IL-4 receptor (hIL-4R) cDNA, which weakly activated c-fos promoter and induced DNA synthesis in BA/F3 cells, failed to elicit these activities in NIH3T3 cells in response to hIL-4.(ABSTRACT TRUNCATED AT 250 WORDS)
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528
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Lee H, Tsuruta R, Koyano-Nakagawa N, Arai N, Arai K, Yokota T. Differential regulation of the IL-5 and IL-2 genes by cAMP. Cytokine 1994. [DOI: 10.1016/1043-4666(94)90207-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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529
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Shiino Y, Inagaki Y, Okamoto T, Miyakawa A, Ono M, Yokota T, Ogawa R, Nakamura J, Nakasato Y, Onda K. [Evaluation of local treatment for unresectable primary liver tumor]. Gan To Kagaku Ryoho 1994; 21:2222-4. [PMID: 7944445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To ascertain the effect of local treatment for unresectable primary liver tumor, 59 patients were investigated retrospectively. Patients were classified into four groups; transcatheter arterial embolization (TAE) group, intermittent intra-arterial infusion chemotherapy group, combined therapy group (TAE+intermittent intra-arterial infusion chemotherapy) and a group without adjuvant therapy. The results revealed that TAE and intermittent intra-arterial infusion chemotherapy both prolonged the survival period. We found that the survival rate depends largely on the therapeutic method. No correlations were confirmed with the liver function nor stage grouping of the tumor. Therefore, we concluded that intermittent intra-arterial infusion chemotherapy is a beneficial treatment, considering its minimal adverse effect, broad indication and the fact that it does not require hospitalization.
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530
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Yokota T, Hansson G. The capacity to express transfected genes is linked to the differentiation stage of vascular smooth muscle cells. Atherosclerosis 1994. [DOI: 10.1016/0021-9150(94)93442-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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531
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Amano T, Ujihara H, Matsubayashi H, Sasa M, Yokota T, Tamura Y, Akaike A. Dopamine-induced protection of striatal neurons against kainate receptor-mediated glutamate cytotoxicity in vitro. Brain Res 1994; 655:61-9. [PMID: 7812790 DOI: 10.1016/0006-8993(94)91597-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The effects of dopamine on glutamate-induced cytotoxicity were examined using the primary cultures of rat striatal neurons. Cell viability was significantly reduced by exposure of cultures to glutamate or kainate for 24 h. In contrast, similar application of N-methyl-D-aspartate (NMDA) or alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) did not induce cytotoxicity. Kainate-induced cytotoxicity was significantly inhibited by kynurenate but not by MK-801. Dopamine at concentrations of 1-100 microM dose-dependently reduced kainate-induced cytotoxicity. Forskolin also significantly reduced kainate cytotoxicity. The neuroprotective effect of dopamine was antagonized by SCH 23390, a D1 receptor antagonist, but not by domperidone, a D2 receptor antagonist. Moreover, kainate-induced cytotoxicity was prevented by SKF 38393, a D1 receptor agonist, or forskolin but not by quinpirole, a D2 receptor agonist. The patch clamp study revealed that the same striatal neurons responded to both kainate and NMDA. During voltage clamp recording, neither kainate-induced currents nor NMDA-induced currents were affected by dopamine. Moreover, dopamine did not affect glutamate- or kainate-induced Ca2+ influx measured with fura-2. These findings indicate that dopamine prevents kainate receptor-mediated cytotoxicity without affecting the kainate receptor activities and intracellular Ca2+ movement. Dopamine-induced neuroprotection may be mediated by an increased intracellular cAMP formed following activation of D1 receptors.
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532
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Koyano-Nakagawa N, Nishida J, Baldwin D, Arai K, Yokota T. Molecular cloning of a novel human cDNA encoding a zinc finger protein that binds to the interleukin-3 promoter. Mol Cell Biol 1994; 14:5099-107. [PMID: 8035792 PMCID: PMC359028 DOI: 10.1128/mcb.14.8.5099-5107.1994] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The CT/GC-rich region (-76 to -47) is one transcriptional regulatory region of the interleukin-3 (IL-3) gene which confers basic transcriptional activity and responds to trans-activation by human T-cell leukemia virus type I-encoded Tax. We isolated three types of cDNAs encoding Cys2/His2-type zinc finger proteins that bind to this region. Two were identical to known transcription factors, EGR1 and EGR2, and the other clone, named DB1, encoded a novel protein of 516 amino acids with six zinc finger motifs. DB1 mRNA was present in human tissues, ubiquitously. Two constitutive transcripts of 4.0 and 4.8 kb in length were present in Jurkat cells. Electrophoretic mobility shift assay, with specific antibodies, showed that DB1 constitutively binds to this region whereas EGR1 binds in a T-cell activation-dependent manner. Overexpression of DB1 in Jurkat cells had no detectable effect on the transcription activity of the IL-3 promoter, in a transient-transfection assay. EGR1 and EGR2 increased IL-3 promoter activity when the transfected cells were stimulated with phorbol-12-myristate-13-acetate and A23187. When DB1 was cotransfected with a Tax expression vector, transcription activity of the IL-3 promoter induced by Tax was significantly increased, while EGR1 and EGR2 were without effect. These results suggest that EGR1 has a role in inducible transcription of the IL-3 gene, while DB1 sustains basal transcriptional activity and also cooperates with Tax to activate the IL-3 promoter.
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533
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Kondo S, Tamura K, Makino S, Yokota T, Ishikawa E, Katakami H, Kohari S. A patient with primary hypoparathyroidism developing hypercalcemia associated with adult T-cell leukemia/lymphoma. Leuk Lymphoma 1994; 14:521-5. [PMID: 7812215 DOI: 10.3109/10428199409049714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A 38-year-old woman was admitted to our hospital with symptoms and signs of hypocalcemia in 1977 and a diagnosis of primary hypoparathyroidism was made with a positive Ellsworth Howard test. She was then lost to follow up until 1992 when she returned this time with symptoms and signs of hypercalcemia. An inguinal lymph node was biopsied showing non-Hodgkin's lymphoma, diffuse pleomorphic type and monoclonal integration of proviral human T-cell lymphotropic virus-1 DNA was detected in lymph node cells indicating ATLL. Serum parathyroid hormone-related peptide (PTHrP) was slightly elevated and the tumor cells were positively stained with anti-PTHrP serum. Combination chemotherapy with vincristine, adriamycin, cyclophosphamide and prednisolone was given to the patient with disappearance of the lymphadenopathy and subsequent normalization of PTHrP levels. Interestingly, the signs and symptoms of hypocalcemia reappeared after the treatment requiring replacement therapy with calcium and vitamin D.
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534
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Shimizu Y, Yokota T, Saito Y, Yuasa T, Miyatake T. [Increased unilateral central motor tract excitability in a patient with corticobasal degeneration]. Rinsho Shinkeigaku 1994; 34:812-6. [PMID: 7994989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In a 64-year-old woman with a clinical diagnosis of corticobasal degeneration, a hyperexcitability of central motor tract was demonstrated. She had akinesia, regidity, myoclonic movement, hyperreflexia, forced grasping and clumusiness on the right extremities. The asymmetry of these symptoms was striking. Dopa therapy was not effective. On single photon emission computed tomography (SPECT), blood perfusion was reduced especially on the left side in the frontoparietal area. She had large C-reflex after the median nerve stimulation only on the affected side. The intensity threshold of motor evoked potential by stimulation on the left motor cortex was lower than that on the right motor cortex. Conditioning stimulation of the median nerve on the affected side, greatly increased MEP size as compared to those of normal subjects, at conditioning-test (C-T) intervals of 40-80 ms; whereas, stimulation on the contralateral side did not. On the other hand, SEP did not have a marked increase or asymmetry in size and SEP recovery curve showed no hyperexcitability. These results indicate there is a hyperexcitability of the central motor tract on the affected side.
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535
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Kusumoto Y, Akita H, Sato Y, Iwata S, Takeuchi Y, Abe T, Sunakawa K, Yokota T. [Bacteriological and clinical studies of biapenem (L-627) in pediatrics]. THE JAPANESE JOURNAL OF ANTIBIOTICS 1994; 47:921-31. [PMID: 7933527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bacteriological and clinical studies in the pediatric field have been performed on biapenem (L-627), a newly-developed carbapenem antibiotic, and the following results were obtained. 1. In the pharmacokinetic study, the plasma concentration of L-627 showed dose-dependant change: Cmax was 14.6 micrograms/ml and AUC was 15.4 micrograms.hr/ml with the administration of 6 mg/kg, while Cmax was 49.2 micrograms/ml and AUC was 60.1 micrograms.hr/ml with the administration of 12 mg/kg. After the administration of 6 mg/kg, the urinary concentration reached maximum within 2 hours and the cumulative urinary excretion rate in the first 6 hours was 49.4%. 2. Antibacterial activities of L-627 against 27 strains of clinical isolates were determined. MICs of L-627 against such Gram-positive cocci as Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus pyogenes were sufficiently low, and those against such Gram-negative rods as Haemophilus influenzae, Escherichia coli and Bordetella pertussis were satisfactory and as low as those of imipenem or ceftazidime. 3. Clinical efficacies of L-627 were evaluated in 36 cases of bacterial infections. The overall efficacy rate was 100%, and excellent responses in 26 cases and good in 10 cases were obtained. As for bacteriological efficacies, all strains except 1 of B. pertussis were eradicated and a high eradication rate of 96.6% was obtained. 4. No side effects were observed in 37 evaluated cases. As abnormal laboratory test results, eosinophilia was noted in 2 cases (5.4%), but they returned to normal values rapidly after the drug was discontinued. From these results, it has been concluded that L-627 is a safe and effective drug to be used in treatment of pediatric infectious diseases.
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536
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Koizumi T, Yokota T, Suzuki KT. Mechanism of cadmium-induced cytotoxicity in rat hepatocytes. Cd-induced acidification causes alkalinization accompanied by membrane damage. Biol Trace Elem Res 1994; 42:31-41. [PMID: 7986659 DOI: 10.1007/bf02990486] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Exposure of rat hepatocytes to cadmium below 50 microM for a short period (10 min) resulted in cellular acidification. Conversely, exposure to Cd more than 50 microM for a long period (60 min) caused cellular alkalinization accompanied by membrane damage as reflected by decrease in cellular K content and loss of intracellular lactic dehydrogenase. In hepatocytes exposed to 5 microM Cd, a concentration sufficient to induce acidification without cytotoxicity, the metal was preferentially associated with the crude nuclei and cell debris fractions, suggesting an interaction between Cd and cell membranes to cause acidification. Omission of bicarbonate from the incubation medium induced cellular acidification. The presence of Cd in this medium did not potentiate the medium-induced acidification. Mg-ATP (25 microM) induced cellular acidification in relation to an increase in the concentration of cytosolic free Ca. The coexistence of Mg-ATP and Cd at the concentrations which had no effect on cellular pH in the presence of either agants induced cellular acidification. These observations suggest that Cd induced cellular acidification by modulating the process connected with the rise in cytosolic free Ca via interaction with plasma membranes. This acidification had no strong immediate cytotoxic actions but led to subsequent cellular alkalinization accompanied with severe cytotoxicity and membrane breakage.
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537
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Yamada M, Inaba A, Yamawaki M, Ishida K, Yokota T, Uchihara T, Eishi Y, Okeda R. Paraneoplastic encephalo-myelo-ganglionitis: cellular binding sites of the antineuronal antibody. Acta Neuropathol 1994; 88:85-92. [PMID: 7941978 DOI: 10.1007/bf00294364] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The cellular binding sites of an antineuronal antibody were characterized in an autopsy case of the paraneoplastic encephalo-myelo-ganglionitis. A 61 year-old woman developed a subacute sensorimotor polyneuropathy and, later, multiple involvement of cranial nerves, disturbance of consciousness, and generalized seizure. An autopsy revealed a small cell lung carcinoma and neuropathological changes that included disseminated encephalitis, spinal anterior horn lesions, severe loss of dorsal root ganglion neurons, and secondary degeneration and loss of the nerve fibers in the spinal posterior column and peripheral nerves. The serum IgG from the patient contained antineuronal antibody(s) including an antibody to 35- to 37-kDa neuronal antigens called anti-Hu as demonstrated in Western blot. In immunohistochemical studies, the serum IgG immunostained neurons of the brains, spinal cords, and dorsal root ganglia of humans or rats. Confocal laser-scanning microscopy revealed binding of the patient's IgG in the neuronal nuclei and cytoplasm, but not in the nucleoli. In immunoelectron microscopic studies, immunolabelling with the IgG was found diffusely in the karyoplasm, excluding nucleoli, and in the cytoplasmic matrix between the cisternae of the reticulums, Golgi apparatus, and mitochondria. Encephalo-myeloganglionitis is a clinicopathological entity frequently associated with the presence of neoplasm and antineuronal antibody, however, the role of the antibody in the pathogenesis remains to be elucidated.
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538
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Watanabe W, Konno K, Ijichi K, Inoue H, Yokota T, Shigeta S. MTT colorimetric assay system for the screening of anti-orthomyxo- and anti-paramyxoviral agents. J Virol Methods 1994; 48:257-65. [PMID: 7989442 DOI: 10.1016/0166-0934(94)90124-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A rapid and sensitive method was developed for screening potential antiviral agents against orthomyxo- and paramyxoviruses, using the MTT method with cell culture suspensions. The cell lines used for the assay were as follows: MDCK cells for the influenza A virus (Fluv. A), HeLa cells for the respiratory syncytial virus (RSV), and Vero cells for the measles virus (MSV). Test compounds were diluted and plated in 96-well round-bottomed microtiter plates. Trypsinized cell suspensions and viruses were added to each well, the plates were then centrifuged (700 x g, 5 min, room temperature), and incubated for several days. The MTT assay was carried out after the degeneration of virus-infected cells became evident. The optical density (OD) of formazan was determined using a computer-controlled microplate reader. With this assay system, the EC50 values of Ribavirin (used as the reference compound) were 3.7 micrograms/ml for Fluv. A, 4.5 micrograms/ml for RSV, and 12.3 micrograms/ml for MSV, respectively. These EC50 values were equivalent to those obtained using the plaque reduction assay. The confluent cell culture system was inadequate for antiviral assays against RSV and MSV when the MTT method was used, because the inhibition of formazan formation was not observed in viral-infected cells. Moreover, the suspension method is more sensitive to the cytotoxicity of antiviral agents than the confluent cell culture system.
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539
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Yokota T, Saito Y, Miyatake T. Conduction slowing without conduction block of compound muscle and nerve action potentials due to sodium channel block. J Neurol Sci 1994; 124:220-4. [PMID: 7964875 DOI: 10.1016/0022-510x(94)90330-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We studied the effect of lidocaine on nerve conduction in vivo. Recovery of the compound muscle action potential (CMAP), sensory nerve action potential (SNAP), and single motor unit potential (MUP) of median nerve stimulation was recorded in four healthy volunteers after intravenous infusion of 20 ml of 0.5% lidocaine. During loading, CMAP and SNAP amplitudes rapidly decreased and their latencies increased. After recovery of the CMAP and SNAP amplitudes, nerve conduction velocity improved gradually over a period of 3-6 h, the amplitudes and configurations of CMAP and SNAP remaining unchanged. The conduction velocity of the single MUP markedly slowed before it is blocked. This indicates that maximum conduction velocity of CMAP and SNAP could be slowed by the partial inactivation of sodium channels without accompanying conduction block. Prolongation of the rise time of depolarization of the axonal membrane potential may be the active mechanism in this slowing because of sodium channel inactivation. Abnormalities in sodium channels at the nodes of Ranvier should be considered as a mechanism of conduction slowing even when there is no conduction block.
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540
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Ishido T, Itabashi M, Ochiai A, Hirota T, Yokota T, Saito D. Morphometric analysis of colorectal dysplasia with image processing. Arch Pathol Lab Med 1994; 118:619-23. [PMID: 8204008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Nuclear and structural abnormalities on the histological specimens of colorectal dysplasias were quantified by using 10 parameters. From the measured values, the following histological findings were obtained: progression from mild to severe dysplasia was associated with an increase in nuclear size, and nuclear arrangement became more irregular. There was, however, no difference between the nuclear size and arrangement in severe dysplasia and those in carcinoma. The nuclei were spindle shaped in mild and moderate dysplasia. On the other hand, they were relatively round in severe dysplasia and carcinoma. Structural abnormalities tended to increase with the histological abnormalities. These results correspond well with the histological abnormalities by which the pathologists grade dysplasia and diagnose carcinoma subjectively. Therefore, these 10 parameters might be useful for quantifying histological characteristics of colorectal dysplasias.
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541
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Shimokado K, Yokota T, Umezawa K, Sasaguri T, Ogata J. Protein tyrosine kinase inhibitors inhibit chemotaxis of vascular smooth muscle cells. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1994; 14:973-81. [PMID: 8199189 DOI: 10.1161/01.atv.14.6.973] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effects of protein tyrosine kinase inhibitors on platelet-derived growth factor (PDGF)-induced chemotaxis in cultured rat aortic smooth muscle cells (SMCs) were investigated to elucidate the role of tyrosine phosphorylation in the chemotaxis of vascular SMCs. Two tyrosine kinase inhibitors, methyl 2,5-dihydroxycinnamate and genistein, inhibited PDGF-induced chemotaxis, the IC50 being 5 and 150 mumol/L, respectively. Methyl cinnamate and genistein partly inhibited the adhesion of SMC to collagen-coated dishes. A chemotaxis assay using double-well culture dishes revealed that both agents also inhibited cell migration after adhesion. H-7, a C kinase inhibitor, did not inhibit either chemotaxis or SMC adhesion at 100 mumol/L. Western blot analysis using anti-phosphotyrosine revealed that the tyrosine kinase inhibitors inhibited the tyrosine phosphorylation of at least two proteins of molecular weight 85 and 95 kD under our experimental conditions. An immunocytochemical study revealed that these inhibitors eliminated tyrosine phosphorylation along the cell margins; these agents also inhibited the reorganization of microtubules and stress fibers, both of which are involved in directional cell locomotion. These findings suggest that tyrosine kinases may play an important role in SMC chemotaxis.
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542
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Akaike A, Tamura Y, Yokota T, Shimohama S, Kimura J. Nicotine-induced protection of cultured cortical neurons against N-methyl-D-aspartate receptor-mediated glutamate cytotoxicity. Brain Res 1994; 644:181-7. [PMID: 7519524 DOI: 10.1016/0006-8993(94)91678-0] [Citation(s) in RCA: 160] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The effects of nicotine on glutamate-induced cytotoxicity were examined using primary cultures of rat cortical neurons. The cell viability was significantly reduced when cultures were briefly exposed to glutamate or N-methyl-D-aspartate (NMDA) then incubated with normal medium for 1 h. A 1-h exposure of the cultures to kainate or alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) reduced cell viability. Incubating cultures with nicotine for 1-24 h protected cortical neurons against glutamate cytotoxicity. Maximum protection against glutamate cytotoxicity was induced with a 2-h nicotine incubation. Exposure to nicotine for up to 2 h did not affect cell viability by itself although cell viability was reduced in a time-dependent manner when the exposure exceeded 4 h. Neuroprotection by nicotine was dependent on both the concentration and incubation period. Nicotine reduced the NMDA cytotoxicity but did not attenuate that of kainate and AMPA. The neuroprotective effects of nicotine against glutamate cytotoxicity were antagonized by mecamylamine and hexamethonium but not by atropine. These results indicate that nicotinic receptor stimulation induces neuroprotection against glutamate cytotoxicity mediated by NMDA receptors.
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543
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Yokota T, Ogawa K, Hagihara A. Dependence of the aboveground respiration of hinoki cypress (Chamaecyparis obtusa) on tree size. TREE PHYSIOLOGY 1994; 14:467-479. [PMID: 14967683 DOI: 10.1093/treephys/14.5.467] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Nighttime respiration was measured at monthly intervals over one year on the aboveground parts of five sample trees in an 8-year-old hinoki cypress (Chamaecyparis obtusa (Sieb. et Zucc.) Endl.) stand, by an enclosed standing-tree method. The respiration rate rose rapidly from early spring to a maximum in June, and decreased abruptly in July and then gradually toward autumn and winter. The seasonal change in the respiration rate was synchronized with stem volume increment rather than with monthly mean air temperature. The respiration rate, r, of individual trees increased with increasing tree dimensions, such as stem volume, v(S), and stem girth at the base of the live crown, G(B). The dependence of respiration rate on tree size was successfully represented by a power function. The r - v(S) dependence was rather stronger than the r - G(B) (2) dependence, especially toward the end of the growing season (from July to September). The observed respiration rate was almost the same as the respiration rate corrected for the monthly mean air temperature. The annual respiration of individual trees was directly proportional to their phytomass or to its increment. Although the annual respiration of individual trees decreased proportionally to the square root of the leaf mass, it decreased abruptly in the range close to the smallest sample tree. Combining the monthly relationship between respiration rate and stem volume with the tree size distribution in the stand, the stand aboveground annual respiration was estimated to be 20.4 Mg CO(2) ha(-1) year(-1) (= 12.5 Mg dry mass ha(-1) year(-1)) for an aboveground biomass of 17.4 Mg ha(-1) with an annual increment of 6.51 Mg ha(-1) year(-1), i.e., the stand aboveground annual respiration amounted to the equivalent of 72% of the biomass or to almost twice the biomass increment.
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544
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Yokota T, Yoshino A, Hirashima F, Komori T, Miyatake T. Increased central motor tract excitability in Creutzfeldt-Jakob disease. J Neurol Sci 1994; 123:33-7. [PMID: 8064318 DOI: 10.1016/0022-510x(94)90200-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Central motor tract excitability was examined in 2 patients with Creutzfeldt-Jakob disease (CJD) and 8 normal subjects by measuring change in the motor evoked potential (MEP) by transcranial magnetic stimulation of the motor cortex after peripheral nerve stimulation. Conditioning stimulation of the median nerve at the wrist greatly increased MEP size (500-1700%) as compared to the size for normal subjects (140-380%) at conditioning-test (C-T) intervals of 30-60 msec for patient 1 and 40-70 msec for patient 2. Moreover, stimulation of the contralateral median nerve at the wrist and of the second and third digits also increased MEP size in the CJD patients; whereas, there was no increase in size in the normals. The time courses of abnormal MEP potentiation were very consistent with the course of the corresponding C reflex. One of the CJD patients had a normal size SEP, and neither patient showed hyperexcitability in SEP-recovery at C-T intervals of 20-60 msec at which there was marked MEP potentiation. These results indicate that there was hyperexcitability of the central motor tract in the CJD patients after the conditioning of muscle and cutaneous peripheral afferents and that it extended to the ipsilateral cortex on the conditioning side as well.
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545
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Tagaya Y, Maeda Y, Mitsui A, Kondo N, Matsui H, Hamuro J, Brown N, Arai K, Yokota T, Wakasugi H. ATL-derived factor (ADF), an IL-2 receptor/Tac inducer homologous to thioredoxin; possible involvement of dithiol-reduction in the IL-2 receptor induction. EMBO J 1994; 13:2244. [PMID: 8187776 PMCID: PMC395080 DOI: 10.1002/j.1460-2075.1994.tb06502.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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546
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Nakayama T, Ohtsuru A, Enomoto H, Namba H, Ozeki S, Shibata Y, Yokota T, Nobuyoshi M, Ito M, Sekine I. Coronary atherosclerotic smooth muscle cells overexpress human parathyroid hormone-related peptides. Biochem Biophys Res Commun 1994; 200:1028-35. [PMID: 8179578 DOI: 10.1006/bbrc.1994.1553] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Parathyroid hormone-related peptide (PTHrP) was originally characterized as a tumor product responsible for hypercalcemia of malignancy and was subsequently found to be produced in many normal tissues. PTHrP is now suggested to play a critical role in the local modulation of vascular smooth muscle function. To elucidate the involvement of PTHrP in coronary atherosclerosis, we immunohistochemically examined coronary arteries obtained from 76 patients with various grades of atherosclerosis and compared the correlation between PTHrP staining and the percent stenosis. Smooth muscle cells at sites of coronary atherosclerosis overexpressed PTHrP, while cells from normal coronary arteries did not. The in situ hybridization using PTHrP riboprobe has also proven the overexpression of PTHrPmRNA in the affected lesions following atherectomy. The intensity of PTHrP expression by smooth muscle cells was significantly correlated with the degree of coronary artery stenosis. Coronary arterial PTHrP overexpression is closely related to the severity and/or progression of coronary atherosclerosis.
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547
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Nakagawa Y, Kosugi H, Miyajima A, Arai K, Yokota T. Structure of the gene encoding the alpha subunit of the human granulocyte-macrophage colony stimulating factor receptor. Implications for the evolution of the cytokine receptor superfamily. J Biol Chem 1994; 269:10905-12. [PMID: 8144676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The receptor for granulocyte-macrophage colony-stimulating factor (GM-CSF) is composed of at least two subunits, alpha and beta. In addition to the conserved cysteine residues and a "WSxWS" motif, the extracellular segments of both subunits have domains that are structurally related to a fibronectin type III domain. This structure is conserved in all members of the cytokine receptor superfamily. We isolated and characterized genomic DNA clones containing the entire coding sequences of the alpha subunit of the human GM-CSF receptor (hGMR alpha). The gene spans approximately 44 kilobases and has 13 exons. The major transcription initiation site was determined to be 195 base pairs upstream of the translation initiation site. The putative promoter region lacks a typical TATA motif and an Sp1 binding site, but contains a purine-rich stretch about 30 base pairs upstream of the transcription initiation site. This stretch is also found in the human interleukin 2 receptor gamma subunit and granulocyte colony-stimulating factor receptor genes. We compared the exon-intron organization of the hGMR alpha gene with other members of the cytokine receptor superfamily and found the genomic organizations to be remarkably well conserved. On the basis of these observations, we propose a model for evolution of this gene family.
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548
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Ichikawa T, Yokota T, Miyatake T. [Cervical magnetic motor-evoked potential--the site of the stimulation]. Rinsho Shinkeigaku 1994; 34:311-317. [PMID: 8026122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Magnetic stimulation over the cervical spine using the 8-shaped coil was studied to determine the optimal site and intensity of stimulation. Twenty-one healthy volunteers and 9 patients with acute inflammatory demyelinating polyradiculoneuritis (AIDP) or chronic inflammatory demyelinating polyradiculoneuritis (CIDP) were examined. Each wing of the 8-shaped coil had a 5 cm outer diameter and the field (maximum 2.2 tesla) was produced with MAGSTIM200 (MAGSTIM company). The coil was placed along the line from the seventh cervical prominence to the acromion on the recorded side (C7 standard line) to give orthodromic stimulation to the motor nerve. The coil position was marked at the contact point of each wing. Motor evoked potential (MEP) was recorded from abductor digitorum minimi muscle by using surface electrodes. In normals, the latency of MEP did not change while the coil was moved vertically from 2 cm rostral to 2 cm caudal of C7 standard line and horizontally from the midline to 6 cm lateral. Increasing the stimulus intensity, MEP latency never got shorter when the intensity was over 180% of motor threshold. On the other hand, the MEP amplitude was highest when the stimulation was given at 4 cm lateral from the midline on the C7 standard line, but our equipment were unable to give the supramaximal stimulation. Our conclusion was therefore that the optimal stimulus point was 4 cm lateral from the midline on the C7 standard line, and the minimal latency of MEP was obtained by the stimulation with the intensity beyond 180% of motor threshold.(ABSTRACT TRUNCATED AT 250 WORDS)
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549
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Ito T, Higuchi T, Hirobe M, Hiramatsu K, Yokota T. Identification of a novel sugar, 4-amino-4,6-dideoxy-2-O-methylmannose in the lipopolysaccharide of Vibrio cholerae O1 serotype Ogawa. Carbohydr Res 1994; 256:113-28. [PMID: 8194067 DOI: 10.1016/0008-6215(94)84231-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A novel sugar in the lipopolysaccharide of Vibrio cholerae O1 serotype Ogawa has been identified. The sugar was liberated from the lipopolysaccharide when hydrolyzed in 10 M HCl at 90 degrees C for 15 min. The sugar was purified and identified as 4-amino-4,6-dideoxy-2-O-methylmannose (2-O-methylperosamine). Since it was found only in the lipopolysaccharide of Vibrio cholerae O1 serotype Ogawa, it seems that the sugar is one of the specific constituents determining Ogawa serotype specificity.
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550
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Sato Y, Iwata S, Akita H, Kobayashi M, Yokota T, Sunakawa K. [Pharmacokinetic and clinical studies on fluconazole in the pediatric field]. THE JAPANESE JOURNAL OF ANTIBIOTICS 1994; 47:272-279. [PMID: 8182898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Pharmacokinetic, bacteriological and clinical studies on intravenous fluconazole (FLCZ) in deep seated mycoses were performed involving 4 pediatric patients. Clinical and bacteriological assessments were made on 4 patients; clinical improvements were good in 3 patients and bacteriological efficacies were rated as "eradicated" in 3 patients. No side effects nor abnormal laboratory values were observed. The pharmacokinetics were investigated in 2 patients. Good serum FLCZ concentrations were obtained at an intravenous dose of 3-6 mg/kg daily. These results indicate that FLCZ is a useful drug in the treatment of pediatric patients with systemic deep-seated mycosis.
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