PubMed Health⌕ Search

Biomedical subjects

H Nakayasu

Publications and source records attributed to H Nakayasu.

At least 37 records · Page 2Linked to original sources
PubMed1995

Crystal violet as an indicator dye for nonequilibrium pH gradient electrophoresis (NEpHGE).

I found that a blue-colored dye, crystal violet, is a useful indicator for nonequilibrium pH gradient electrophoresis (NEpHGE). Unlike isoelectrofocusing, NEpHGE basically depends on the nonequilibrium gradient; therefore, the location of the proteins differs with acrylamide concentration or voltage used. To get reproducible results, colored marker which indicates the end of the electrophoresis might be very helpful. Crystal violet is an adequate dye for this purpose. This deeply colored, nontoxic material has a positive charge and migrated slightly faster than almost all proteins on NEpHGE. This dye affected neither the formation of pH gradient nor migration of proteins. Moreover, the ratio of migration (protein/dye) in the NEpHGE gels did not change under different conditions tested. Therefore, the addition of trace amounts of this dye gives a convenient endogenous color indicator to determine the end of the NEpHGE. Other positively charged dyes could be used as such an indicator, but some dyes (for example, methylene blue) lost their color by reduction during electrophoresis. Some dyes (for example, ethidium bromide) migrate too fast; therefore, they were not suitable indicators for NEpHGE.

Animals↗
PubMed1995

Molecular cloning of a cDNA clone encoding a phosphoprotein component related to the Ig receptor-mediated signal transduction.

We have shown previously that a 52-kDa phosphoprotein (p52) co-precipitated with Ig receptor (IgR)-associated MB-1 protein was inducibly phosphorylated by the stimulation with 12-O-tetradecanoyl-phorbol-13-acetate. By immunizing the 52-kDa protein co-precipitated with MB-1, we prepared a mAb (19-14), which can immunoprecipitate the p52 and the associated kinase molecule. Immune complex kinase assay with the 19-14 mAb showed that the p52 is associated with a novel kinase molecule and is involved in IgR-mediated signal transduction. Here we isolated a cDNA clone (alpha 4) from a murine bone marrow cDNA library in lambda gt-11 vector by the 19-14 mAb. The alpha 4 cDNA encodes a novel protein of 340 amino acids with multiple potential phosphorylation sites. The 1.4-kb alpha 4 mRNA is expressed in various cells including cell lines of B lineage, T lineage, monocytic, fibroblast, and normal organs such as liver, spleen, thymus, and brain. To study the molecule encoded by the alpha 4 cDNA, we produced a chimeric protein of the glutathione S transferase (GST)-alpha 4 in pGEX-3X expression vector. The 19-14 mAb binds to the GST-alpha 4 fusion protein. Rabbit anti-alpha 4 Ab prepared by immunizing the GST-alpha 4 fusion protein immunoprecipitated a 52-kDa phosphoprotein from WEHI-231 cells. The 52-kDa phosphoprotein immunoprecipitated by the anti-alpha 4 Ab is tightly associated with kinase activity that is similarly observed with the p52 protein reported previously. Moreover, the 52-kDa phosphoprotein immunoprecipitated with the anti-alpha 4 Ab is identical to the p52 by the protein comparison on non-equilibrium pH gradient gel electrophoresis/SDS-PAGE, isoelectric focusing/SDS-PAGE, and V8 protease mapping. The 52-kDa phosphoprotein is associated with functional components that are inducibly phosphorylated by anti-IgM stimulation. These results suggested that the alpha 4 gene-encoded molecule is functionally involved in the IgR-mediated signal transduction in B cells.

Amino Acid Sequence↗
PubMed1995

Effective anticonvulsant therapy in a patient with limb shaking: a case report.

A case is described of a patient with limb shaking in whom anticonvulsant therapy was effective for inhibiting attacks. A 70 year old female developed rhythmical involuntary limb shaking of the right upper and lower limb in April 1986. She was diagnosed as having transient ischemic attacks and was followed up under treatment with an antiplatelet drug. Subsequently, anticonvulsant therapy was also initiated on an outpatient basis. In August 1991, she was admitted with shaking of the right upper and lower limbs. Low molecular dextran was ineffective for inhibiting limb shaking attacks, but intravenous injection of diazepam was effective. Phenytoin and phenobarbital was used in combination. No limb shaking attacks occurred thereafter. The involuntary movement was the same as that observed at the onset of the disease. Though no changes were observed in the pattern of the involuntary movement, anticonvulsant therapy was effective in preventing and inhibiting attacks. This finding is inconsistent with previous reports. It is possible that epileptic factors are involved in the development of this condition.

Aged↗
PubMed1995

The two-color analysis of the T-lymphocyte subsets in experimental allergic neuritis in rats.

We examined the T-cell subsets in the peripheral blood, spleen and lymph nodes during the course of experimental allergic neuritis (EAN) by using two-color analysis. In the acute phase, the percentages of CD4+ major histocompatibility complex (MHC)-II+ cells and CD8+ MHC-II+ cells in the lymph nodes of EAN rats were significantly higher than in the control rats. In the recovery phase, the percentage of CD4+ CD45RC+ cells and CD8+ CD45RC+ cells in the lymph nodes in EAN rats were significantly higher than in the control rats. However, significant changes of the T-cell subsets were not detected in either the spleen or the peripheral blood during the course of EAN. These results suggest that CD4+ MHC-II+ cells, CD8+ MHC-II+ cells, CD4+ CD45RC+ cells and CD8+ CD45RC+ cells may play a role in the course of EAN. The relationship between these double staining cells and EAN is discussed.

Analysis of Variance↗
PubMed1995

The CD5+ B cells and myasthenia gravis.

A high frequency of CD5+ B lymphocytes in the peripheral blood of patients with myasthenia gravis (MG) has been reported recently. These results seem to indicate an attractive linkage between CD5+ B lymphocytes and autoantibodies against Acetylcholine receptor in MG. We examined the frequency of CD5+ B cells in 20 patients with MG and 21 normal healthy controls by two-color flow cytometry. However, there were no significant differences in the percentages of CD5+ B lymphocytes between the two groups. We also examined the frequency of CD5+ B lymphocytes in the resected thymus of patients. The frequency of CD5+ B lymphocytes in the thymus was low and similar pattern to that in the peripheral blood. We checked the antibody (Ab) production against the human acetylcholine receptor in either CD5+ B or CD5- B lymphocytes using B lymphoblastoid cell line generated from the lymphocytes of 11 patients with anti-AChR Abs in the sera. Abs against the AChR in the human were mostly produced by CD5- B, not CD5+ B lymphocytes. The anti-AChR Abs (IgG) production of CD5+ B cells and CD5- B cells (mean +/- SD) were 6.8 +/- 2.4 fmol/ml and 18.5 +/- 17.6 fmol/ml, respectively. These results suggest that in MG, the frequencies of the CD5+ B lymphocytes in PBL may be genetic background and that there may be no strong linages between AChR Ab production and CD5+ B lymphocytes.

Adult↗
PubMed1995

[A case of dissecting aneurysm of the basilar artery presented as superior pons type of Foville's syndrome].

Here we report a 47-year-old man with dissecting aneurysm of the basilar artery who developed Foville's syndrome due to upper pons involvement. At first he had an abrupt onset of dysarthria and weakness in his left upper and lower extremities during his work. Neurological examination on admission revealed mild disturbance of consciousness, absent light reaction on the left side, hypesthesia of the left face, absent gag reflex, dysarthria, and left hemiparesis with ataxia. On the second hospital day he developed paralysis of conjugate eye movement to the right, left central facial palsy, and left hemiplegia, and hyperhidrosis of the left side of the body. He was diagnosed to have superior pons type of Foville's syndrome. Computed tomography showed low density area in the right upper pons, and the basilar artery had marked lateral shift, dilatation, and calcification. Vertebral angiography demonstrated dissecting aneurysm of the basilar artery. Although it is very rare that dissecting aneurysm of the basilar artery causes the brain stem symptoms, its possibility should be considered when computed tomography shows marked lateral shift, dilatation, and/or calcification of the basilar artery.

Aortic Dissection↗
PubMed1993

Immunoaffinity purification and characterization of gamma-aminobutyric acid (GABA)B receptor from bovine cerebral cortex.

We developed a novel method for immunoaffinity purification of gamma-aminobutyric acid (GABAB) receptor from bovine cerebral cortex using a monoclonal antibody, which specifically recognizes an 80-kDa GABA-binding protein (Nakayasu, H., Mizutani, H., Hanai, K., Kimura, H., and Kuriyama, K. (1992) Biochem. Biophys. Res. Commun. 182, 722-726). The GABA binding activity in the solubilized synaptic membrane preparation was adsorbed on the antibody-conjugated beads and was eluted as a single protein band of 80 kDa by an acidic buffer, pH 2.5. The purified preparation mimicked the GABAB receptor in its binding activity for GABA, baclofen (GABAB receptor agonist) and 2-hydroxysaclofen (a GABAB receptor antagonist). The purified preparation was reconstituted with partially purified GTP-binding protein and an adenylylcyclase preparation on a phospholipid membrane. On addition of GABA or baclofen to the reconstituted membrane, the adenylylcyclase activity was inhibited, and this inhibition was antagonized by 2-hydroxysaclofen. Moreover, this inhibition by GABA was not observed in a system reconstituted system without either the 80-kDa GABA-binding protein or the GTP-binding protein. These results are strong evidence that the 80-kDa antigenic protein is the GABAB receptor. This is the first report of the nearly complete purification of the GABAB receptor.

Adenylyl Cyclases↗
PubMed1993

Cerebral GABAB receptor: proposed mechanisms of action and purification procedures.

The GABAB receptor in brain is one of the GABA receptor subtypes, and has been found to be negatively coupled to adenylate cyclase and phosphatidylinositide turnover. This receptor easily solubilizes from cerebral synaptic membrane preparations by 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS) in the presence of asolectin. GABAB receptor solubilized from bovine cerebral cortex was purified using baclofen-coupled affinity beads (baclofen-coupled Toyopearl beads). Using these procedures, almost pure GABAB receptor (80 KDa protein) was obtained in the affinity eluate. A monoclonal antibody has been also raised against the purified GABAB receptor. The antibody recognized a protein of about 80 KDa in bovine brain synaptic membrane. Immunoabsorbent agarose beads conjugated with the antibody were able to remove more than 90% of the baclofen suppressive GABA binding activity in the solubilized synaptic membrane, and this system was found to be useful for the immunoaffinity column chromatographic separation of GABAB receptor. Preliminary studies of immunohistochemical visualization of GABAB receptor in the rat cerebellum suggested that this receptor may be exclusively localized at the presynaptic site of GABAergic neurons.

Adenylyl Cyclases↗
PubMed1993

Structure and function of cerebral GABAA and GABAB receptors.

The receptor for GABA (gamma-aminobutyric acid), an inhibitory neurotransmitter in the brain, has been classified into GABAA and GABAB types. The GABAA receptor was purified by means of affinity column chromatography using benzodiazepine as an immobilized ligand. The results indicated that the GABAA receptor consists of several subunits and forms a GABA-gated Cl- channel, which is coupled with the benzodiazepine receptor. The molecular weight of the GABAA receptor complex was estimated to be approximately 300 kDa. Furthermore, cDNA cloning of GABAA receptor subunits was performed and the primary structure of these subunits was deduced. The results suggested that these subunits possess four transmembrane domains in their structure which are important for the formation of the Cl- channel. On the other hand, activation of GABAB receptors induced the inhibition of adenylyl cyclase activity and phosphatidylinositol turnover via inhibitory GTP-binding proteins such as G(i) and/or G(o). The GABAB receptor was purified using baclofen affinity and immunoaffinity column chromatographies. It was confirmed that the purified GABAB receptor protein is about 80 kDa in its molecular weight. This protein is capable of inducing the inhibition of adenylyl cyclase when it is reconstituted with G(i)/G(o) protein in the phospholipid vesicle system. Currently available data indicate that GABAA and GABAB receptors in the central nervous system are distinct not only in terms of their molecules but also their signal transduction systems. However, the primary structure and synaptic localization of GABAB receptor molecules in the brain remain to be clarified.

Amino Acid Sequence↗
PubMed1993

[Effect of folic acid for treatment of homocystinuria due to 5,10-methylenetetrahydrofolate reductase deficiency].

Deficiency of 5,10-methylenetetrahydrofolate reductase (MTHFR) leads to deficient remethylation of homocysteine and is one of the causes of homocystinuria. Only 28 patients have been reported so far. A 15-year-old boy with mild mental retardation was admitted in our hospital because of progressive difficulty in walking. He is the second child. The paternal grandparents are first cousins. On admission, clinical examination revealed mild disturbance of consciousness, left hemiparesis, truncal ataxia, pyramidal tract signs in the lower limbs and sensory disturbance in his feet. There was no marfanoid symptoms nor ectopia lentis. EEGs showed slow activity with sporadic spike and wave complexes. Peak latencies of N20 of median nerves SEPs, the third and 5th wave of ABR and P100 of VEP were delayed. The CT scan showed mild cortical atrophy and MRI revealed increased intensity on T2-weighted images in the cerebral white matter. Biochemical studies revealed homocystinuria with homocystinemia. Both plasma methionine and serum folic acid were low. Serum vitamin B12 and methylmalonic acid in urine were normal. The lymphoblastoid cell line, transformed by Epstein-Barr virus of lymphocytes of the patient, could not grow when homocysteine was substituted in the culture medium for methionine. The normal control cell line grew naturally under the same condition. A diagnosis of homocystinuria due to MTHFR deficiency was made. The patient was on various therapeutic regimens for about 70 days. Treatment with high doses of folic acid (400 mg/day) resulted in disappearance of homocysteine in plasma, remarkable decrease of homocysteine in urine and increase of methionine in plasma of the patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Monoclonal antibody to GABA binding protein, a possible GABAB receptor.

A monoclonal antibody has been raised against a partially purified preparation for the GABAB receptor. The antibody recognized a protein of about 80 kDa in bovine brain synaptic membrane. Immunoabsorbent agarose beads conjugated with the antibody were able to remove, without visible changes in electrophoresed profiles of total proteins, over 90% of the baclofen suppressive GABA binding activity (designated herein, GABAB receptor binding activity) in the solubilized synaptic membrane fraction. Moreover, the addition of GB-1 antibody directly inhibited the GABA binding activity in the crude synaptic membrane fraction. These results indicate that the monoclonal antibody obtained here recognizes the GABA binding protein, or more specifically a GABAB receptor.

Animals↗
PubMed1992

[A case of intracranial multiple nonspecific granulomas related to rheumatic disease: with special reference to magnetic resonance imaging].

We encountered a rare case of a 48-year-old man with intracranial multiple granulomas secondarily caused by rheumatic disease. This was proven surgically after an 11-year course of remissions and deteriorations. In 1980, at the age of 32 years, the patient was first seen at the clinic of Neurology of the University Hospital, complaining of swelling and arthralgia of the joints of the knee, ankle, and wrist and with remittent fever and visual disturbance. The patient was diagnosed as having possible rheumatoid arthritis, and treated with administration of 30mg/day of prednisolone, which greatly improved the symptoms. The administration of 5 to 10mg/day of prednisolone had been continued after discharge from hospital. In 1985, visual acuity of the left eye decreased, and left facial hypesthesia developed. The patient was rehospitalized at the same clinic, and treated with 100mg/day of prednisolone, which again diminished the symptoms. Computed tomography(CT) on admission showed a high density mass with contrast enhancement in the left cavernous region. In addition to the left cavernous mass, a high density mass was detected by CT in the left parietal lobe, in 1987. Visual acuity of the left eye deteriorated in 1989. Because his response to prednisolone had decreased, the visual symptom was treated with gold sodium, which acted effectiveness. Symptoms deteriorated again in 1990. Early in 1991, CT and magnetic resonance imaging showed a new mass at the right frontal lobe, while the mass in the left cavernous region had increased in size. The patient was transferred to the clinic of Neurosurgery for surgical treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Nuclear matrins: identification of the major nuclear matrix proteins.

A preparative two-dimensional polyacrylamide gel system was used to separate and purify the major Coomassie blue-stained proteins from the isolated rat liver nuclear matrix. Approximately 12 major proteins were consistently found. Of these, 5 proteins represented identified proteins, including nuclear lamins A, B, and C, the nucleolar protein B-23, and residual components of core heterogeneous nuclear ribonucleoproteins. The remaining eight major proteins termed the nuclear matrins consisted of matrin 3 (125 kDa, slightly acidic), matrin 4 (105 kDa, basic), matrins D-G (60-75 kDa, basic), and matrins 12 and 13 (42-48 kDa, acidic). Peptide mapping and two-dimensional immunoblot studies indicate that matrins D-G compose two pairs of related proteins (matrins D/E and F/G) and that none of the matrins resemble the nuclear lamins or any of the other major proteins detected on our two-dimensional gels. Subfractionation immunoblot experiments demonstrated the nearly exclusive localization of matrins F/G and other matrins to the nuclear matrix fraction of the cell. These results were further supported by indirect immunofluorescence microscopy that showed a strictly interior nuclear localization of the matrins in intact cells in contrast to the peripherally located nuclear lamins. We conclude that the nuclear matrins are a major class of proteins of the nuclear matrix interior and are distinct from the nuclear lamins.

Animals↗
PubMed1991

Dynamic computed tomography and functional imaging in cerebral arterial occlusive disease: analysis in the chronic phase.

Dynamic CT was conducted on 10 patients with internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion or stenosis and 14 controls. All the patients were chronic phase and they only presented small infarctions on CT. Those with ICA or MCA occlusions and insufficient collateral circulations showed delayed mean transit time and peak time of the affected side on functional image and in parameter analysis (P less than 0.01) compared with those of controls. A statistically significant positive coefficient of correlation was noted between the degree of the anterior horn dilatation of lateral ventricle and delay in mean transit time of the affected MCA area (r = 0.62, P less than 0.01).

Aged↗
PubMed1991

[Two cases of adult Down's syndrome presenting parietal low uptake in 123I-IMP-SPECT].

We performed 123I-IMP-SPECT to patients with Down's syndrome who were supposed to have neuropathological findings of dementia of the Alzheimer's type. In case 1, a 52-year-old man with dementia, bilateral posterior parietal low uptake and right temporal low uptake were noted. Uptake was markedly lower in the right hemisphere. Case 2, a 38-year-old man not exhibiting clinical features of dementia, presented slightly decreased uptake in bilateral posterior parietal areas. We conclude that the patterns of abnormally decreased uptake in these cases of Down's syndrome are similar to those in dementia of Alzheimer's type, and that there is a possibility to detect the predemented stage of Down's syndrome by 123I-IMP-SPECT.

Adult↗
PubMed1991

[A mechanism of cheiro-oral syndrome due to brainstem lesions, a case of a dissecting aneurysm of the basilar artery].

A 42-year-old woman developed an abrupt onset of severe headache, nausea, vomiting, unstable gait and numbness around the right side of her mouth and in her right hand. Neurological examination revealed bilateral pyramidal tract signs and hypesthesia of her right palmar tip and the right side of her mouth. However, pain and temperature sensibility was preserved. Cerebrospinal fluid was clear and colorless. CT scan showed an enhancing mass in the prepontine cistern compressing the pontine base. Vertebral angiography revealed irregular narrowing of bilateral vertebral arteries (string sign) proximal to a fusiform aneurysm on the entire length of the basilar artery. MRI showed double lumina in the wall of the aneurysm. The medial lemniscus conducts the discriminatory tactile and the deep sensory impulses from the extremities. The ventral ascending tract of the trigeminal nerve conducts the discriminatory tactile sensory impulses from the face. These two tracts lie close together in the pontine tegmentum, which is also a watershed area of the paramedian branches and circumferential branches of the basilar artery. We suggest that in this case the dissecting aneurysm caused ischemia of these two tracts in the left pontine tegmentum, presenting right cheiro-oral syndrome.

Adult↗