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Biomedical subjects

Y Oda

Publications and source records attributed to Y Oda.

At least 433 records · Page 24Linked to original sources
PubMed1992

"Solid" variant of aneurysmal bone cyst (extragnathic giant cell reparative granuloma) in the axial skeleton and long bones. A study of its morphologic spectrum and distinction from allied giant cell lesions.

BACKGROUND: Giant cell reparative granuloma is generally considered to be a benign tumor-like bone lesion. Its involvement of axial skeleton and long bones is rare. METHODS: Seven cases of extragnathic giant cell reparative granuloma (GCRG), which arose in the axial skeleton and long bones, were analyzed clinicopathologically and compared with allied lesions consisting of 31 cases of aneurysmal bone cyst (ABC) and 83 cases of giant cell tumor of bone (GCT). RESULTS: These occurred in patients ranging in age from 8-36 years; two were in the vertebrae; two, in the clavicles; one, in a rib; one, in the humerus; and one in the tibia. None of the patients with GCRG had a recurrence despite incomplete resection. Its skeletal distribution and average associated patient age were similar to those of ABC. Histologically, they were characterized by florid fibroblastic proliferation with osteoclast-like giant cell-rich areas, stromal hemorrhage, and newly formed bone or osteoid trabeculae. The histologic features could be found around either the characteristic aneurysmal cysts or sinuses, although they were lacking any large blood-filled spaces. CONCLUSIONS: The overlapping clinical and histologic features between GCRG and ABC and their similar biologic behavior represent related responses to an intraosseous hemorrhage. The authors prefer to use the term "solid variant of aneurysmal bone cyst" to describe this lesion.

Adolescent↗
PubMed1992

Glucagonlike peptide-1(7-36)amide suppresses glucagon secretion and decreases cyclic AMP concentration in cultured In-R1-G9 cells.

We previously reported that GLP-1(7-36)amide had glucagonostatic action as well as insulinotropic action in the perfused rat pancreas. In this study, we examined the effect of GLP-1(7-36)amide on glucagon secretion and cAMP concentration in glucagon-secreting cell line, In-R1-G9. GLP-1(7-36)amide (1nM) significantly suppressed glucagon secretion and decreased cAMP concentration in the cells. GLP-1(1-37) did not affect glucagon secretion. It is suggested that inhibitory effect of GLP-1(7-36)amide on glucagon secretion is at least partly mediated by adenylate cyclase system.

1-Methyl-3-isobutylxanthine↗
PubMed1992

Distribution of the glucose transporters in human brain tumors.

In the present study, we have investigated the expression of both the erythrocyte-type (GLUT1) and the brain-type (GLUT3) glucose transporter isoforms in primary human brain tumors. In situ hybridization made it possible to localize and semiquantify both GLUT1 and GLUT3 mRNAs of individual cells in all 18 samples examined. More signals for GLUT3 mRNA than for GLUT1 mRNA were found over astrocytoma cells, while the reverse was the case in all 6 meningiomas. In astrocytomas, for both mRNAs, the density of silver grains over tumor cells was well correlated with the malignancy of the cells. This correlation was, as was also confirmed by Northern blot analysis, more marked with GLUT3 mRNA than with GLUT1 mRNA. In 2 of 5 anaplastic astrocytomas and in all 3 glioblastomas, numerous tumor cells with large amounts of both mRNAs tended to surround the perivascular regions. "Tumor vessels" with endothelial proliferation, an almost pathognomonic feature of glioblastomas, expressed much GLUT3 mRNA but no significant GLUT1 mRNA, while a single- or a few-layered capillary endothelium expressed much GLUT1 mRNA. The distribution of both mRNAs was in good accordance with that of both proteins. Our results suggest that the expression of both glucose transporter isoforms may contribute to the maintenance of human brain tumors and that the expression of the GLUT3 isoform may be closely related to the malignant change of astrocytomas and particularly related to the aberrant neovascularization which accompanies glioblastomas.

Astrocytoma↗
PubMed1992

Conalbumin-conjugated silica gel, a new chiral stationary phase for high-performance liquid chromatography.

A new chiral stationary phase using conalbumin (from chicken egg white) was developed for high-performance liquid chromatography. Chiral resolution of racemic azelastine, an antiallergic drug, was achieved on a conalbumin-conjugated silica gel column. The effects of the pH, the concentration of organic solvents and salts in the mobile phase, and the temperature on the capacity factor and resolution of racemic azelastine were examined. This column shows good stability and can separate optical isomers with an aqueous mobile phase. It should be very useful in studies on pharmacokinetics and in clinical chemistry.

Chromatography, High Pressure Liquid↗
PubMed1992

Effect of cavity-modulating mutations on the stability of Escherichia coli ribonuclease HI.

The size of the cavity around Ser68 of Escherichia coli ribonuclease HI was modulated by amino acid substitutions to examine the effects on the stability of the enzyme. Five mutant proteins, Ser68----Gly, Ser68----Ala, Ser68----Thr, Ser68----Val and Ser68----Leu, were constructed. Each of the mutant proteins exhibited at least 40% of the enzyme activity of the wild-type protein. The stabilities of the mutant proteins were determined from urea-denaturation and thermal-denaturation curves. Among the five mutations, only the Ser----Val mutation resulted in an increase in the stability of the enzyme. The melting temperature, tm, at pH 3.0 of the mutant protein Ser68----Val was increased by 1.9 degrees C. Its free-energy change of unfolding in the absence of urea, delta G(H2O), and the midpoint of the denaturation curve, [D]1/2, were also increased by 5.4 kJ/mol and 0.18 M, respectively. The increase in the stability of the enzyme is probably due to the filling of the cavity space around Ser68 by valine. However, the mutation of Ser68 to glycine or leucine residues resulted in a considerable decrease in stability. In these cases, some conformational changes occur, as suggested by the CD and 1H-NMR spectra of these mutant proteins.

Base Sequence↗
PubMed1992

Expression of murine interleukin 7 in a murine glioma cell line results in reduced tumorigenicity in vivo.

We have examined the immunoregulatory effect of local and continuous secretion of interleukin 7 (IL-7) from murine glioma cells (203-glioma) engineered by murine IL-7 gene transfection. Secretion of IL-7 from glioma cells did not result in morphology or growth rate changes but did reduce tumorigenicity in vivo in proportion to the amount of IL-7 produced. This reduction in tumorigenicity could be reversed in a dose-dependent fashion by injection of anti-IL-7 neutralizing monoclonal antibody at the tumor site. Mice immunized with IL-7-producing glioma cells showed a specific immune response to 203-glioma but not to two other syngeneic cell lines (B-16, a melanoma, and YM-12, a fibrosarcoma). IL-7-producing glioma cells were not rejected in mice depleted of CD8+ cells but were rejected in mice depleted of CD4+ or NK1.1+ cells. These results suggest that CD8+ T cells may play an important role in tumor rejection.

Animals↗
PubMed1992

Both beta 1- and beta 2-adrenoceptors are involved in mediating phosphatidylcholine secretion in rat type II pneumocyte cultures.

A primary culture of rat type II pneumocytes was used for the pharmacological and functional characterization of beta-adrenoceptor subtypes. The beta-adrenoceptor agonists, isoprenaline, dobutamine and procaterol concentration dependently increased the secretion of phosphatidylcholine. These effects were attenuated by propranolol. The effect of dobutamine was attenuated by atenolol, and that of procaterol by ICI 118,551. Isoprenaline-induced secretion was attenuated by the combination of the two blockers but not by each one alone. In conclusion, both beta 1- and beta 2-adrenoceptor subtypes mediate phosphatidylcholine secretion in rat type II pneumocytes.

Adrenergic beta-Agonists↗
PubMed1992

Design and synthesis of an alpha-helical peptide containing periodic proline residues.

A thirty-residue peptide (PERI COIL-1) has been designed with a new type of alpha-helical structure, which is capable of folding into an amphiphilic helix bending at 4 periodic prolines in the sequence. Two such helices should form a dimer by supercoiling about one another in an antiparallel direction in the design. With this arrangement, close packing between them is maintained through the hydrophobic interaction pattern called 'leucine zipper'. PERI COIL-1 has been obtained by solid-phase peptide synthesis, and characterized by circular dichroic spectroscopy, sedimentation equilibrium experiments and NMR. The result of the analyses shows that it preferentially forms a helical tetramer in aqueous solution.

Amino Acid Sequence↗
PubMed1992

Analysis of the close relationship between human astrocytoma-specific antigens detected by murine monoclonal antibodies and c-kit proto-oncogene product.

Tyrosine-specific phosphorylated proteins found exclusively on the cell surface of human astrocytomas were previously identified with murine monoclonal antibodies, designated as GA-17, GB-4 and GC-3. The purpose of this study was to further characterize the antigens and investigate the relationship between them and c-kit protooncogene product. We demonstrated that the antigens had protein kinase activity. Moreover, GA-17 reacted with c-kit protein expressed on the membrane of A172 human glioblastoma cells.

Antibodies, Monoclonal↗
PubMed1992

Long-term potentiation of inhibitory circuits and synapses in the central nervous system.

Glycinergic inhibition evoked disynaptically in the teleost Mauthner cell by stimulation of the contralateral eighth nerve exhibits long-term potentiation following classical tetanization of that pathway. This enhancement occurs at the synapses between primary afferents onto second-order interneurons and the connections between these inhibitory cells and the Mauthner neuron. The evidence for modifications of glycinergic transmission is that the slope of the relation between the presynaptic volley and the synaptic conductance can be greater after the tetanus. This increase in gain is still manifest after pharmacological block of potentiation at the excitatory synapse with glutamate antagonists. Inhibitory long-term potentiation is induced by tetani weaker than those required for enhancement of the monosynaptic excitation of the other (ipsilateral) Mauthner cell. Thus, in vivo learning can alter the balance between excitation and inhibition within a network by modifying one or both of them.

Animals↗
PubMed1992

A case of treatment-related leukoencephalopathy: sequential MRI, CT and PET findings.

A case of treatment-related leukoencephalopathy is presented. A patient with medulloblastoma was postoperatively treated with craniospinal axis irradiation. One month after irradiation, weekly intrathecal administration of methotrexate was performed 4 times to treat cerebrospinal fluid dissemination of the tumor. Two months after the initiation of intrathecal chemotherapy, the patient became somnolent and developed decerebrate posturing. Magnetic resonance imaging showed diffuse leukoencephalopathy. Positron emission tomography revealed a diffuse decrease in glucose uptake in the deep white matter. Auditory evoked potential also showed diffuse abnormalities, not only in the cerebrum, but also in the brain stem. High dose intravenous leucovorin rescue was attempted without any neurologic improvement.

Blood Proteins↗
PubMed1992

1H NMR studies of deuterated ribonuclease HI selectively labeled with protonated amino acids.

Two-dimensional (2D) 1H NMR experiments using deuterium labeling have been carried out to investigate the solution of ribonuclease HI (RNase HI) from Escherichia coli (E. coli), which consists of 155 amino acids. To simplify the 1H NMR spectra, two fully deuterated enzymes bearing several protonated amino acids were prepared from an RNase HI overproducing strain of E. coli grown in an almost fully deuterated medium. One enzyme was selectively labeled by protonated His, Ile, Val, and Leu. The other was labeled by only protonated His and Ile. The 2D 1H NMR spectra of these deuterated RNase HI proteins, selectively labeled with protonated amino acids, were much more simple than those of the normally protonated enzyme. The simplified spectra allowed unambiguous assignments of the resonance peaks and connectivities in COSY and NOESY for the side-chain protons. The spin-lattice relaxation times of the side-chain protons of the buried His residue of the deuterated enzyme became remarkably longer than that of the protonated enzyme. In contrast, the relaxation times of the side-chain protons of exposed His residues remained essentially unchanged.

Amino Acid Sequence↗
PubMed1992

Anesthetic management with eptazocine hydrobromide in patients receiving long-term antipsychotic medication.

We evaluated the usefulness of eptazocine hydrobromide as an adjuvant in patients receiving antipsychotics for long periods. Patients anesthetized with enflurane alone (enflurane group, n = 11), were compared with those anesthetized with enflurane and eptazocine hydrobromide 1 mg.kg(-1) (eptazocine group, n = 10). The mean daily dose of the antipsychotics, converted into the amount of chlorpromazine, was 345 mg in the eptazocine group and 366 mg in the enflurane group. The duration of antipsychotic medication was 14 years in the eptazocine group and 17 years in the enflurane group. The maintenance concentration of enflurane was 0.37% in the eptazocine group and 0.67% in the enflurane group, being significantly lower in the former group. The interval between the termination of operation and removal of the endotracheal tube was slightly shorter in the eptazocine group. The discriminant function of circulatory stability obtained from the measurement of systolic blood pressure and heart rate during anesthesia in the eptazocine group was 481, being significantly lower than 539 in the enflurane group. Both absolute and relative instabilities of systolic blood pressure and heart rate were slightly smaller in the eptazocine group. No side effects associated with eptazocine hydrobromide administration were observed. These results suggest the safety and usefulness of this analgesic in the anesthetic management of patients receiving long-term antipsychotic medication.

Journal Article↗
PubMed1992

Changes in expression of the endogenous beta-galactoside-binding 14-kDa lectin of chick embryonic skin during epidermal differentiation.

Changes in the expression pattern of the gene for the endogenous beta-galactoside-binding 14-kDa lectin of chick embryo were examined immunohistochemically during epidermal differentiation in vivo and in vitro with special reference to detailed localization of the 14-kDa lectin. The gene expression was visualized by the HRP-staining method following in situ hybridization, in which sulfonated cDNA was employed as a probe. The 14-kDa lectin gene expression (mRNA) was detected mainly in the intermediate layer of the epidermis: it was faint in 13-day-old embryos, gradually increased in intensity during epidermal differentiation, and became intensely positive in 17-day-old embryo. The expression of the gene in skin explants was suppressed by vitamin A, which induces mucous metaplasia of the epidermis in vitro. The anti-14-kDa lectin reaction was positive mainly in the intermediate layer of the differentiating epidermis, coinciding chronologically with expression of the gene at the light microscopic level. Immunoelectron microscopy revealed that the positive reaction was primarily localized in desmosomes, in tonofilament bundles anchored to the desmosomes, along the outer surface of the plasma membrane, and in the intercellular space. Essentially the same staining pattern was observed in differentiating epidermis in vitro. The positive reaction was markedly reduced in the epidermis in which differentiation had been suppressed in vitro by the addition of vitamin A.

Animals↗
PubMed1992

Primary intracerebral malignant lymphoma associated with different histological types of carcinoma: report of two cases.

Two rare cases with histologically proven multiple primary neoplasms are described: an association of intracerebral malignant lymphoma with hepatocellular carcinoma in one case and with squamous cell carcinoma of the uterine cervix in the other. Therapeutic problems pertinent to the coexistence of primary intracerebral malignant lymphoma and neoplasms of a different histological type are discussed.

Aged↗
PubMed1992

A sensitive umu test system for the detection of mutagenic nitroarenes in Salmonella typhimurium NM1011 having a high nitroreductase activity.

A sensitive umu test system for the detection of mutagenic nitroarenes has been developed using a new tester strain Salmonella typhimurium NM1011 having a high nitroreductase activity. The new strain was constructed by subcloning the bacterial nitroreductase gene into a plasmid pACYC184 and introducing the plasmid into the original strain S. typhimurium TA1535/pSK1002 harboring a fusion gene umuC'-'lacZ (pSK1002). Thus, the tester strain enabled us to monitor the genotoxic activities of various nitroarene compounds by measuring the beta-galactosidase activity in the cells. The sensitivity of strain NM1011 was compared with that of the parent tester strain S. typhimurium TA1535/pSK1002 or a nitroreductase-deficient strain S. typhimurium NM1000 with respect to the induction of umuC gene expression by 17 mutagenic nitroarenes. The newly developed strain with high nitroreductase activity had about 3 times higher nitrofurazone-reductase activity than the parent strain and was highly sensitive to the compounds 2-nitrofluorene, 1-nitronaphthalene, 2-nitronaphthalene, 1-nitropyrene, m-dinitrobenzene, 4,4'-dinitrobiphenyl, 3-nitrofluoranthene, 3,7-dinitrofluoranthene, 3,9-dinitrofluoranthene, 5-nitroacenaphthene and 2,4-dinitrotoluene. By contrast, the enzyme-deficient strain did not show any considerable response to 2-nitrofluorene, m-dinitrobenzene, 1-nitronaphthalene, 2-nitronaphthalene, 1-nitropyrene, 4,4'-dinitrobiphenyl, 3-nitrofluoranthene, 3,7-dinitrofluoranthene, 2,4-dinitrotoluene and 5-nitroacenaphthene. These results suggest that the newly developed tester strain with high nitroreductase activity is very useful for the detection of potent mutagenic nitroarene compounds.

Cloning, Molecular↗