Biomedical subjects

K Shibata

Publications and source records attributed to K Shibata.

At least 505 records · Page 28Linked to original sources

PubMed1990

Subtype-specific cyclic AMP-dependent histone H1 phosphorylation at the differentiation of mouse neuroblastoma cells.

At the initial phase of cell differentiation in mouse neuroblastoma (N18) induced by dibutyrylcyclic AMP (dbcAMP), an additional site of histone H1 was extensively phosphorylated. Forskolin and various phosphodiesterase inhibitors also induced both cell differentiation and H1 phosphorylation at the identical site. The phosphorylation preferentially occurred in a single H1 subtype (H1c) among the five (H1a-e) fractionated by high performance liquid chromatography. The three H1 subtypes of N18 (H1c, H1d, and H1e) were phosphorylated in vitro, and their amino acid sequences of the phosphopeptides were identical to the known sequence of rabbit H1 peptides containing a serine 37 residue. However, the amount of H1a and H1b phosphorylations was negligible. The serine residue was replaced by threonine residue in H1a, and H1b did not have a homologous peptide. The tryptic phosphopeptides of H1 in N18 were identical to that in rat liver H1 induced by glucagon (Langan, T.A. (1969) Proc. Natl. Acad. Sci. USA 64, 1276-1283). The results indicate that 1) the response of H1 subtypes to cAMP-dependent protein kinase in vivo and in vitro is H1 subtype-specific, and 2) the H1c phosphorylation may play an important role in the restrictive area of chromatin in both cell differentiation and hormonal stimulation mediated by cAMP.

1-Methyl-3-isobutylxanthine↗

PubMed1990

Chemical analyses, local Shwartzman reactivity, and body weight-decreasing activity of aqueous-phenol extracts of Mycoplasma salivarium cells. Biological activities of Mycoplasma salivarium.

Aqueous-phenol extracts of Mycoplasma salivarium ATCC 23064 cells (APM) showed demonstrable differences from lipopolysaccharides (LPSs) of Veillonella rodentium ATCC 17743. These were as follows: smaller amounts of amino sugars and an absence of 2-keto-3-deoxyoctonate; local Shwartzman reactivity and body weight-decreasing activity, even though the activities were rather weak compared with those of LPSs. Therefore, phenol-water extractive components of Mycoplasma salivarium might be of pathogenic importance in mediating damaging effects on the periodontium.

Animals↗

PubMed1990

The relation between EEG and mental development following cardiac surgery performed under simple deep hypothermia in children.

In order to assess the accuracy of electroencephalography (EEG), in children who have undergone cardiac surgery under simple deep hypothermia, the relation between IQ or schoolwork achievement and the duration of circulatory arrest was investigated in 75 such children. Abnormal preoperative EEG's were found in 16 per cent of the children while abnormal postoperative EEG's were found in 17 per cent. The children were divided into 4 groups, according to pre- and postoperative EEG results. Schoolwork achievement scores ranged between 3.0 and 3.2, the difference among the groups being insignificant. Moreover, no significant shift in IQ was found among the groups. Finally, regarding the number of children who were able to go on to a higher level of education, including high school then college or university, again no significant differences were found among the 4 groups. In a comparison with the number of such children in neighboring Nagasaki prefecture able to continue on to a higher level of education, no significant differences were seen either. The findings and statistics of this investigation therefore indicate that pre- and postoperative EEG's are not always a reliable reference for assessing the prognosis of cerebral activity.

Achievement↗

PubMed1990

Coexisting thymic carcinoid tumor and thymoma.

Thymic carcinoid tumors are unusual neoplasms that are different from thymomas. We report a case of coexisting thymic carcinoid tumor and thymoma associated with myasthenia gravis. The clinicopathological findings are discussed with a review of the literature.

Carcinoid Tumor↗

PubMed1990

Lineage non-specific down regulation of P210bcr/abl in the CML cell line, KU-812-F, during differentiation.

CML cell line, KU-812-F, originally established from a patient with Philadelphia-chromosome-positive chronic myelocytic leukemia has maintained the ability to differentiate into both granuloid (basophilic) and erythroid lineages. The expression of P210bcr/abl in KU-812-F cells during differentiation was studied by immunoblotting and immunoprecipitation. Immunoblotting with anti-phosphotyrosine sera revealed the down-regulation of P210bcr/abl in both granuloid and erythroid lineages. Immunoprecipitation with anti-abl antibodies of 35S-methionine-labelled cells revealed a reduced rate of synthesis of P210bcr/abl protein. Cytotoxic agents that caused growth inhibition of the cells did not alter the expression of P210bcr/abl. These results indicate that the down regulation of P210bcr/abl protein is a lineage non-specific event accompanied by differentiation.

Cell Differentiation↗

PubMed1990

Immunomodulatory effect of a newly synthesized compound, TOK-8801 (N-(2-phenylethyl)-3,6,6-trimethyl-5,6-dihydroimidazo [2,1-b]thiazole-2-carboxamide) on antibody production in vivo and delayed-type hypersensitivity in mice.

The immunopharmacological effects of a newly synthesized compound in vivo, TOK-8801 (N-(2-phenylethyl)-3,6,6-trimethyl-5,6-dihydroimidazo[2,1-b]thi azo le-2- carboxamide), on the anti-SRBC plaque-forming cell (PFC) response and delayed-type hypersensitivity (DTH) reaction were investigated. Oral administration of TOK-8801 (0.1-10 mg/kg) resulted in the suppression of the PFC responses to varying doses of antigen (5 x 10(6), 2 x 10(7), 1 x 10(8)) in C3H/He strain mice (7 W) which are high responders to SRBC antigen. On the other hand, the compound augmented the PFC response in aged mice (8-9 months) in which the PFC response was markedly depressed compared with that in young mice. In the experiment of the methylated human serum albumin-induced DTH reaction, TOK-8801 augmented the reaction in low responder (C57BL/6) mice by oral administrations of 0.1-1 mg/kg for 5 days from the sensitization, whereas suppressed the reaction in high responder (ICR) mice. These immunopharmacological actions of TOK-8801 were compared in dose and activity with those of lobenzarit and bucillamine. Thus, these results suggest that TOK-8801 may act as an immunomodulating agent and would be expected to be a useful agent for autoimmune diseases such as rheumatoid arthritis.

Adjuvants, Immunologic↗

PubMed1990

Effect of dietary tryptophan levels on the urinary excretion of nicotinamide and its metabolites in rats fed a niacin-free diet or a constant total protein level.

We previously found that the sum total urinary excretion of nicotinamide and its metabolites in growing rats did not increase as the level of dietary casein increased. So, we investigated how the urinary excretion of nicotinamide and its metabolites changed when rats were fed nicotinic acid-free diets containing 10, 20 or 40% casein, or when they were fed diets containing nicotinic acid and the same level of protein but different levels of tryptophan. The latter diets were 10% casein-30% gelatin, 20% casein-20% gelatin or 40% casein. With the nicotinic acid-free diets, the sum total urinary excretion of nicotinamide and its metabolites was almost the same in the groups fed the 20 and 40% casein diets; however, it was significantly lower in the group fed the 10% casein diet. With diets containing the same level of protein, the sum total urinary excretion of these compounds in the groups fed the 10% casein-30% gelatin, 20% casein-20% gelatin and 40% casein diets were about 5, 7 and 11 mumol/d, respectively, values that were significantly different from each other. Therefore, it was found that only when the total protein intake was constant did the sum total urinary excretion of nicotinamide and its metabolites increase with increasing intake of tryptophan.

Administration, Oral↗

PubMed1990

Hemagglutinating activity of Mycoplasma salivarium and its attachment to sheep red blood cells.

Mycoplasma salivarium (ATCC 23064) and 10 other strains isolated from human saliva agglutinated red blood cells of rabbits and human types A and O weakly, and those of sheep (SRBC) and human type B strongly. Glycoproteins on the surface of the organism cells and N-acetylneuraminic acid residues and some sugars on SRBC were suggested to be involved in agglutination of SRBC. Protein A-like activity was detected in the organism cells. The organism cells were also shown to attach to SRBC in PPLO broth (Difco) supplemented with 10% horse serum, and bivalent metal ions were suggested to be involved in the attachment. The organism cells attaching to SRBC activated complement through the alternative pathway and lyzed the SRBC.

ABO Blood-Group System↗

PubMed1990

Expression of a human cocaine-sensitive dopamine transporter in Xenopus laevis oocytes.

The human dopamine transporter was expressed in Xenopus laevis oocytes following injection of mRNA isolated from human brain substantia nigra. The specific accumulation of [3H]dopamine into these oocytes was time and Na+ dependent. Furthermore, [3H]dopamine accumulation was prevented by coincubation of oocytes with dopamine (100 microM) or with the dopamine uptake inhibitors GBR 12909 (1 microM) or cocaine (3 microM). In contrast, oocyte injection of mRNA isolated from human globus pallidus, an area devoid of dopamine neuron perikarya, did not elicit expression of the dopamine transporter. Oocyte expression of the human dopamine transporter can be used for the further characterization and cloning of this low-abundance membrane protein.

Animals↗

PubMed1990

Molecular conformations of aminophenylimidazoles exhibiting antiulcer activities.

To experimentally clarify a possible stereostructure-activity relationship proposed for H2-receptor antagonists, three 5-aminophenylimidazoles (1, 2 and 3), in which respective amino groups are located on the ortho, meta and para positions of the benzene ring, were synthesized and examined for their conformational characteristics using X-ray diffraction and proton nuclear magnetic resonance (1H-NMR) methods, and for antiulcer activities on rats and H2-receptor antagonist activities in guinea pig. The ortho isomer 1, which preferentially formed an intramolecular N-H (amino)...N (imidazole) hydrogen bond, showed the highest antiulcer activity with half the efficacy of cimetidine. On the other hand, none of 1, 2 and 3 showed significant H2-receptor antagonist activity. Based on these results, the conformational characteristic for the exhibition of antiulcer activity has been discussed.

Aniline Compounds↗

PubMed1990

Characterization of crystalline L-carnosine Zn(II) complex (Z-103), a novel anti-gastric ulcer agent: tautomeric change of imidazole moiety upon complexation.

A novel crystalline Zn(II) complex of L-carnosine was prepared and evaluated for inhibitory activity against gastric ulceration in rats. The complex was found to be much more active than various other Zn(II) compounds. It was characterized by means of infrared (IR) spectroscopy, solid-state carbon-13 (13C) and nitrogen-15 (15N) 1H-cross-polarization (CP) magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The spectroscopic data indicated that L-carnosine coordinates to Zn(II) as a quadridentate ligand. A comparison of the 13C-NMR signals of the imidazole carbons of the complex with those of several histidine derivatives revealed that a tautomeric change of imidazole moiety had occurred upon complexation. The binding mode of the complex was considered to be analogous to that of the corresponding Cu(II) complex.

Animals↗

PubMed1990

Niacin catabolism in rodents.

Urinary excretion of nicotinamide and its metabolites in mouse, guinea pig, and hamster with a pharmacological amount of nicotinamide or N1-methylnicotinamide (MNA) was investigated to compare them with those of rat. In mouse, nicotinamide N-oxide was the most abundant metabolite, accounting for 35% of urinary excretion of nicotinamide and its metabolites, and followed by N1-methyl-2-pyridone-5-carboxamide (2-Pyr), 20%; nicotinamide, 18; MNA, 16%; and N1-methyl-4-pyridone-3-carboxamide (4-Pyr), 11%. In guinea pig, 2-Pyr was the most abundant metabolite, accounting for 80% of urinary excretion, and was followed by MNA, 11%; nicotinamide, 3%; 4-Pyr, 3%; and nicotinamide N-oxide, 3%. In hamster, nicotinamide was the most abundant metabolite, accounting for 44%, and followed by 2-Pyr, 21%; nicotinamide N-oxide, 15%; MNA, 10%; and 4-Pyr, 10%. Urinary excretion of nicotinic acid and nicotinuric acid was not detected in mouse, guinea pig, and hamster. When a pharmacological amount of nicotinamide was intraperitoneally injected into mouse, the excretion of nicotinamide N-oxide increased to 79.7% of the nicotinamide metabolites, while those of MNA (4.9%), 2-Pyr (11.2%), and 4-Pyr (6.3%) decreased. Nicotinic acid and nicotinuric acid were again not detected. When a pharmacological amount of nicotinamide was intraperitoneally injected into guinea pig and hamster, the deamidated metabolites nicotinic acid and nicotinuric acid occupied significant percentages of the nicotinamide metabolites: 50.4% and 26.3%, respectively, in guinea pig; and 7.7% and 79.5%, respectively, in hamster. The ratio of 2-Pyr to 4-Pyr excretion did not change when nicotinamide or MNA was located into mouse, guinea pig, and hamster. From these results, the catabolism of nicotinamide in rodent is discussed.

Animals↗

PubMed1990

Tachykinin gene expression in rat limbic nuclei: modulation by dopamine antagonists.

The content and nature of the preprotachykinin (PPT; i.e., substance P/neurokinin A-encoding) messenger RNAs (mRNAs) present in rat brain striatum and limbic tissues were determined by RNA protection experiments. The rank order of PPT mRNA concentration was striatum greater than nucleus accumbens much greater than bed nucleus of the stria terminalis greater than hypothalamus, amygdala and septum. The proportion of beta-(full length) to gamma-(minus exon 4) PPT mRNA was invariant (40/60) among the tissues tested. Because these brain regions receive prominent dopaminergic innervations, the effects of repeated treatment with dopamine antagonists (antipsychotic drugs) on PPT gene expression were assessed. The prototypical dopamine antagonists haloperidol and chlorpromazine decreased striatal PPT mRNA, had no effect on PPT mRNA in the nucleus accumbens or bed nucleus of the stria terminalis, and increased septal PPT mRNA levels. In contrast, the atypical antipsychotic drugs clozapine and l-sulpiride did not alter striatal or septal PPT mRNA, but increased PPT mRNA content in the nucleus accumbens and bed nucleus. The correlation between the effects of typical and atypical antipsychotic drugs on rat striatal and limbic PPT gene expression and their clinical side effects and therapeutic efficacy is discussed.

Animals↗

PubMed1990

[A case of membranous lipodystrophy (Nasu) with diffuse cerebral white matter involvement and cerebellar atrophy on brain CT and MRI].

A 37-year-old female was admitted to our hospital because of progressive dementia and gait disturbance. She was healthy until 34 years of age when she had difficulty in walking and memory disturbance with personality changes. At age 36, she developed urinary incontinence and dementia. The neurological examination demonstrated euphoric mental state, emotional incontinence, severe dementia, paraplegia, dysmetria, choreic movements in both arms and urinary incontinence. Diffuse hyperreflexia and bilateral Babinski signs were observed. Routine laboratory examination showed slightly increased erythrocyte sedimentation rate and alkaline phosphatase. Electroencephalogram revealed diffuse irregular slow waves. X-ray film of the ulnar bone revealed osteoporotic and cystic lesions. The biopsy of the left tibial bone showed a specific membranous cystic structure. Computerized tomography (CT) of the brain showed symmetric, diffuse low density areas in the cerebral white matter and severe atrophy of the cerebellum. T2-weighted magnetic resonance imaging (MRI) revealed diffuse high intensity areas in the cerebral white matter. The present case is characterized by diffuse changes in cerebral white matter and cerebellar atrophy, which have been never reported in Nasu-Hakola disease. The diffuse cerebral white matter changes shown by CT and MRI appear to indicate that this patient is the first case of leukodystrophy of sudanophilic type since the original case reported by Nasu et al.

Adult↗

PubMed1990

[Postoperative recurrence of the patients with the stage I, II non small cell lung cancer].

The study population consisted of 42 patients with squamous cell carcinoma and 46 patients with adenocarcinoma of stage I, 12 patients with squamous cell carcinoma and 7 patients with adenocarcinoma of stage II lung cancer who underwent curative surgical resection. Local recurrence and metastasis was not significant in both histological types in stage I, II. Lung and bone metastasis was dominant in the both cases of squamous cell carcinoma, adenocarcinoma and brain metastasis in the cases of adenocarcinoma. Concerning the period to first recurrence following the operation, the recurrences of stage I squamous cell carcinoma occurred 28% within 1 year after surgery, 28% during 1-2 years after surgery and those of stage II squamous cell carcinoma occurred 11% within 1 year. On the other hand, the recurrences of stage I adenocarcinoma occurred 25% within 1 year, 31% during 1-2 years, 25% over 2 years after surgery and those of stage II adenocarcinoma occurred 13% within 1 year. In the cases with squamous cell carcinoma, the 5-year survival rate (56%) of stage I was not significant compared with those (59%) of stage II. On the other hand, in the adenocarcinoma, the 5-year survival rate (54%) of stage I was significantly better than those (29%) of stage II (p less than 0.05).

Adenocarcinoma↗

PubMed1990

[The expectation of diagnostic radiology in the therapy of lung cancer].

The summary of expectation is as follows. 1) A precise evaluation of cancer invasion into neighboring organs and distinction between a carcinoma and the peripheral atelectasis. 2) An evaluation of the degree of bronchial wall invasion of cancer which developed within bronchial cavity. 3) The differential diagnosis of the peripheral small lung cancer from other peripheral nodules as tuberculoma. 4) The qualitative diagnosis in lymphnode metastasis.

Adenocarcinoma↗

PubMed1990

[Surgical treatment of cor triatriatum: report of four cases].

Four cases of cor triatriatum are reported. Cases 1 and 2 had IIA, case 3 had IA, and case 4 had IIIB 1 type of cor triatriatum according to Lucas-Schmidt classification. Cases 1 and 2 were diagnosed by echocardiography preoperatively. They were not performed cineangiocardiography because of pulmonary congestion. Case 3 had type IA so called classical type, which is hemodynamically identical to mitral stenosis and supravalvular stenosing ring. The clinical features are depend on the size of the communication between accessory chamber and true left atrium. As case 4, he had been diagnosed of simple atrial septal defect preoperatively, careful echocardiographic examination was essential for accurate diagnosis. In case 2 with hypoplastic left heart, secondary surgical repair is considered to be desirable followed by balloon dilatation of two atrial septal defects communicated to accessory chamber and to true left atrium. Thus, we expect development of hypoplastic left ventricle.

Adolescent↗

PubMed1990

[Open heart surgery of a patient with Basedow's disease: a case report].

A case of open heart surgery of Basedow's disease was presented. A 46-year-old female was admitted for mitral regurgitation with heart failure. She suffered from Basedow's disease ten years ago, and was treated with MMI. With this treatment, her thyroid function became normal and did well over the last four years. When open heart surgery (MVR) was performed, examination of her thyroid gland revealed mild hypothyroidism, and the operation could be performed without any thyroidal trouble. We conclude, in case of heart disease with Basedow's disease, the operation can be performed without any thyroidal trouble if the thyroid function is controlled well to euthyroid for a long term. Euthyroid condition lasted 4 years in this case.

Female↗