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H Nakayasu

Publications and source records attributed to H Nakayasu.

50 records · Page 3Linked to original sources
PubMed1990

Suppression of actively induced and passively transferred experimental allergic neuritis by cyclosporin A.

The effect of cyclosporin A (CyA) on experimental allergic neuritis (EAN) was examined. CyA suppressed the development of actively induced EAN. The earlier treatment with CyA was begun, the more effective was its effect. CyA was effective even after the development of clinical signs. In actively induced EAN, cessation of CyA treatment lead to the development of EAN. However, in passively induced EAN, it did not. We could not find any differences in the distribution of infiltrating T cell subsets between the control group and the CyA-treated group.

Animals↗
PubMed1990

[Intracranial multiple granuloma preceded by rheumatic disease--a case report].

In 1980, a 38-year-old man had remittent fever, swelling and arthralgia of the knee, ankle and wrist joints, as well as visual disturbance due to bilateral iritis. On his admission to our hospital, his laboratory data showed neutrophilia, normocytic normochromic anemia, hepatomegaly, hepatocellular damage, and a strongly positive RA test. All the microbiological examinations were negative. Thirty mg of prednisolone improved his symptoms and abnormal laboratory findings. Due to persistent mild arthralgia, he had continued to take 5-10 mg of prednisolone and analgesics until 1985 when he was readmitted to our hospital. In 1983, he began to complain of a steady pain around his left eye, and he sometimes had double vision. In 1985, he began to complain of decreasing left visual acuity and sensory disturbance in his left face in addition to pain in and around the eye. On his 2nd admission to our hospital, the neurological examination revealed involvement of the 2nd and 3rd cranial nerves and the 1st branch of the 5th cranial nerves of the left side. Laboratory data showed a positive RA test with RAHA titer at 1:320 and IgM at 216 mg/dl, but he had no joint deformities. The computed tomography (CT) of the brain demonstrated a high density mass of his left cavernous sinus extending to the left orbital apex. The prescription of the high dose of prednisolone (100 mg/day) relieved ophthalmic pain and improved visual acuity and neurological involvement within a week. Prednisolone was then gradually decreased to 10 mg. In 1986, he had partial and complex partial seizures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Mapping replicational sites in the eucaryotic cell nucleus.

We have used fluorescent microscopy to map DNA replication sites in the interphase cell nucleus after incorporation of biotinylated dUTP into permeabilized PtK-1 kangaroo kidney or 3T3 mouse fibroblast cells. Discrete replication granules were found distributed throughout the nuclear interior and along the periphery. Three distinct patterns of replication sites in relationship to chromatin domains in the cell nucleus and the period of S phase were detected and termed type I (early to mid S), type II (mid to late S) and type III (late S). Similar patterns were seen with in vivo replicated DNA using antibodies to 5-bromodeoxyuridine. Extraction of the permeabilized cells with DNase I and 0.2 M ammonium sulfate revealed a striking maintenance of these replication granules and their distinct intranuclear arrangements with the remaining nuclear matrix structures despite the removal of greater than 90% of the total nuclear DNA. The in situ prepared nuclear matrix structures also incorporated biotinylated dUTP into replication granules that were indistinguishable from those detected within the intact nucleus.

Animals↗
PubMed1987

Nuclear actin and transport of RNA.

The role of nuclear actin filaments in the RNA transport was investigated. Mouse lymphoma cells, L5178Y, were labeled for 20 min with 3H-uridine, and the isolated nuclei were incubated in a medium consisting of 0.25 M sucrose, 10 mM Tris-HCl (pH 7.5), 2 mM CaCl2, 1 mM ATP and 1mM PMSF. Release of the rapidly labeled RNA from the nuclei was temperature-dependent and was stimulated by ATP. Phalloidin, an inhibitor of actin filament depolymerization, had no effect on the system at 10 or 100 micrograms/ml. Therefore, actin filament depolymerization may not be involved in the transport of RNA.

Actins↗
PubMed1987

Effect of corticosteroid on passively transferred experimental allergic neuritis.

Effect of prednisolone on experimental allergic neuritis (EAN) in Lewis rats was studied. In order to exclude the influence of residual antigens, we evaluated the effect in EAN passively transferred with living lymphoid cells. Prednisolone, when administered after the passive transfer, prevented EAN both clinically and histologically, but when administered after the clinical onset, it had little influence on the course of the disease. Prednisolone was suspected to have suppressed the sensitized cells, but to have had no remarkable effect after the clinical onset.

Animals↗
PubMed1986

Preferential association of acidic actin with nuclei and nuclear matrix from mouse leukemia L5178Y cells.

Nuclear matrix prepared from mouse leukemia L5178Y cells contained not only the two common actin isomers, beta and gamma actins, but also two additional acidic species of actin (pI 5.1 and 5.3). An anti-actin antibody recognized these acidic species as well as beta and gamma actins on a nitrocellulose filter following western blotting of two-dimensional electrophoresis. These acidic species were co-purified with beta and gamma actins using DNase I-Sepharose affinity chromatography on the nuclear matrix. Limited digestion of the acidic actin with protease V8 or trypsin gave very similar peptide fragments as did digestion of beta and gamma actins. These acidic actins were found to be distributed in the nuclear fraction, but were scarcely detectable in the cytoplasmic fraction. One of the acidic actins (pI 5.3) was found in all subnuclear fractions (DNase extract, high-salt extract and nuclear matrix), while the other species, the most acidic actin (pI 5.1), was localized predominantly in the nuclear matrix.

Actins↗
PubMed1985

Association of rapidly-labelled RNAs with actin in nuclear matrix from mouse L5178Y cells.

More than 90% of rapidly-labelled nuclear RNA was associated with a nuclear matrix prepared from mouse leukemia L5178Y cells. The binding was not affected with up to 4 M NaCl; however, these RNAs were released from the nuclear matrix by treatment with a low ionic strength buffer (5 mM Tris-HCl buffer, pH 7.5, containing 1 mM ATP, 1 mM dithiothreitol, 0.2 mM ethylenediaminetetraacetic acid (EDTA) and 0.4 mM calcium chloride), without destruction of the sphere of the nuclear matrix. Actin filaments in the nuclear matrix were depolymerized with this buffer accompanied with rapidly-labelled RNAs. When the depolymerization was inhibited by slight modifications of the low ionic strength buffer (replacement of ATP by the same concentration of GTP; replacement of calcium ion by the same concentration of magnesium ion; addition of 20 micrograms/ml of phalloidine, which is a specific inhibitor of actin depolymerization), the release of rapidly-labelled RNAs from the nuclear matrix was also inhibited. The complex containing rapidly-labelled RNAs and matrix proteins was solubilized by a sonication from the nuclear matrix, and subjected to cesium chloride equilibrium centrifugation. Rapidly-labelled RNAs were concentrated on the bottom of the gradient accompanied with a small number of proteins (68K, 60K, 43K and 40K). The 43K protein was identified as actin by immunoblotting. By RNase digestion before equilibrium centrifugation, actin in the bottom fractions disappeared. These results suggest that rapidly-labelled RNAs anchor on the actin filaments in the nuclear matrix.

Actins↗
PubMed1985

Ultrastructural localization of actin in nuclear matrices from mouse leukemia L5178Y cells.

We examined the distribution of actin in isolated nuclear matrices from mouse leukemia L5178Y cells using an anti-actin antibody and protein A-conjugated colloidal gold particles. Before immunogold staining, we partially digested the surface lamina of the nuclear matrix with trypsin (Nakayasu and Ueda, Exp. Cell Res. 143, 55-62, 1983) to allow penetration of the gold particles into the nuclear matrix. Trypsin digestion slightly modified the internal structure of the nuclear matrix, but did not affect the actin content in the nuclear matrix nor the reactivity of actin with the antibody. Many colloidal gold particles were present along fibrogranular structures in the nuclear matrix. The results reported here confirm the existence of actin in the interior of the nuclear matrices of L5178Y cells.

Actins↗
PubMed1984

Small nuclear RNA-protein complex anchors on the actin filaments in bovine lymphocyte nuclear matrix.

When the nuclear matrix from bovine lymphocytes was digested by RNase-depleted trypsin, the bulk of the matrix proteins, except actin, were hydrolyzed. The digestion left rapidly sedimented spherical structures (trypsin-treated nuclear matrix), which mainly were composed of actin (Nakayasu, H. and K. Ueda. Exp. Cell Res. 143, 55-62, 1983). Almost all the small nuclear RNAs of the original nuclear matrix remained associated with these actin spheres after trypsin digestion. By sonication, the small nuclear RNPs (snRNPs) in both untreated and trypsin-treated nuclear matrices were solubilized in association with proteinous filaments of various size. The sedimentation pattern of these snRNP complexes was not changed by the digestion of the bulk of the proteins. The snRNP complex was adsorbed on rabbit muscle myosin-Sepharose then eluted by the addition of 5 mM ATP. We concluded that snRNPs are associated with actin filaments in the nuclear matrix of bovine lymphocytes.

Actins↗
PubMed1983

Association of actin with the nuclear matrix from bovine lymphocytes.

Nuclear matrix prepared from bovine lymphocytes contained a significant amount of actin. Both nuclear matrix actin and rabbit muscle actin showed the same electrophoretic mobility on SDS-gel. The matrix-associated actin could be separated into three isoproteins which may correspond to alpha-, beta- and gamma-actin. The most acidic spot of these isoproteins co-migrated with rabbit muscle actin (alpha-actin) on two-dimensional electrophoresis. The amino-acid composition of the nuclear matrix actin was closely related to that of rabbit muscle and to that of porcine brain actin. Moreover, the actin filaments, treated with 0.75 M guanidine hydrochloride, changed from the polymerized form of the nuclear matrix actin into a monomeric form (G-actin), which had strong inhibitor activity against pancreatic DNase I. From this inhibition, the actin content of the nuclear matrix was estimated to be about 12% of total matrix protein. When the nuclear matrix was digested with trypsin, the bulk of matrix protein was hydrolyzed, but about 80% of the actin remained associated with sphere structures (trypsin-treated nuclear matrix) precipitable by low speed centrifugation. SDS-gel analysis revealed that actin was one of the major components of the trypsin-treated nuclear matrix, which had a similar size and structure as the untreated nuclear matrix. The fibrogranular structure and residual nucleoli of the original nuclear matrix were well preserved against trypsin digestion; however, the peripheral lamina was removed. These results indicate that the matrix-associated actin is localized predominantly in the matrix interior, where it presumably interacts closely with the fibrogranular structure and/or the residual nucleoli.

Actins↗