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Y Ueda

Publications and source records attributed to Y Ueda.

At least 19 recordsLinked to original sources
PubMed1995

Role of Tyr residues in the contact region of anti-lysozyme monoclonal antibody HyHEL10 for antigen binding.

It has been shown that Tyr residues are unusually localized in the regions of antibodies responsible for contact with antigens (Padlan, E. A. (1990) Proteins Struct. Funct. Genet. 7, 112-124). In order to clarify the role of these Tyr residues in antigen binding, the interaction between hen egg white lysozyme (HEL) and its monoclonal antibody HyHEL10, whose structure has been well studied in complex with its antigen, was investigated. Four Tyr residues in the VH chain (HTyr-33, HTyr-50, HTyr-53, and HTyr-58) were replaced with Ala, Leu, Phe, or Trp, and the interactions between these mutant Fv fragments and HEL were studied by inhibition assay of the enzymatic activity of HEL and isothermal titration calorimetry. Twelve mutant Fv fragments could be expressed, but two mutants (HY50W and HY58W) could not be obtained in the Escherichia coli expression system, and a further two mutants (HY33A and HY50A) could not be purified by affinity chromatography. It was shown by inhibition assay that Tyr residues at each mutated site made positive contributions to the interaction to different degrees. Thermodynamic studies showed that the role of Tyr residues in antigen binding was to obtain enthalpic energy. The roles of Tyr residues in antibody HyHEL10 for the association with antigen, HEL, can be summarized as follows: 1) formation of hydrogen bonds by the hydroxyl group, 2), creating more favorable interactions through the aromatic ring and decreasing the entropic loss upon binding, and 3) allowing hydrophobic interaction through the side chain. The four Tyr residues studied here were found to play significant roles in the association in various ways.

Animals↗
PubMed1995

Types of nuclear endonuclease activity capable of inducing internucleosomal DNA fragmentation are completely different between human CD34+ cells and their granulocytic descendants.

A hallmark of apoptosis is internucleosomal DNA fragmentation resulting from the activation of endonucleases. We characterized the endonuclease activity of human myeloid cell nuclei that cleaved their own nuclear chromatin to oligonucleosomal length fragments. Polymorphonuclear leukocytes (PMNs) of normal peripheral blood contained both Ca2+/Mg(2+)-dependent and DNase II-like acidic endonuclease activities in their nuclei. Immature myeloid cells of normal bone marrow at various stages of granulocytic maturation had similar nuclease activities. In contrast, a clear difference was shown in the circulating CD34+ cells, in that only Mg(2+)-dependent, Ca(2+)-independent endonuclease activity was detected. Consistent with these findings is the emergence of the Ca2+/Mg(2+)-dependent and acidic endonuclease concomitantly with the disappearance of the Mg(2+)-dependent endonuclease when CD34+ cells were induced to differentiate in vitro toward granulocytes. Leukemic cell lines of all lineages also had Mg(2+)-dependent nuclease activity. Our results suggest an association of the Mg(2+)-dependent endonuclease with hematopoietic progenitor cells and that the relative activities of the nuclear nuclease in human myeloid cells change substantially during granulocytic differentiation.

Antigens, CD↗
PubMed1995

Unclassified poxvirus: characterization and physical mapping of Cotia virus DNA and location of a sequence capable of encoding a thymidine kinase.

DNA from Cotia virus, an unclassified poxvirus, was mapped by overlapping fragment analysis using the restriction endonucleases HindIII, PstI, BamHI, XhoI, SalI, and SmaI. The linear genome was 177 kbp in length and possessed inverted terminal repeats and cross-links. A Cotia virus thymidine kinase (TK) gene was detected and mapped to about 74 kbp from the left end of the genome using degenerate oligonucleotide probes. Nucleotide sequencing of the TK gene revealed an open reading frame (ORF) that encoded a peptide of 178 amino acids. An A/T-rich sequence, TAA AAA TGA ATA AATA, and a transcription termination signal, TTTTTGT, were revealed upstream and just downstream of the ORF, respectively, consistent with the characteristic features of an early poxvirus gene. Cotia virus resembles swinepox virus based on the restriction profiles generated by endonucleases and shares amino acid sequence similarity with orthopox, leporipox, Yaba, and fowlpox viruses.

Amino Acid Sequence↗
PubMed1995

Interphase and metaphase detection of the breakpoint of 14q32 translocations in B-cell malignancies by double-color fluorescence in situ hybridization.

The breakpoint of 14q32 translocations found in B-cell malignancies was delineated specifically in both metaphase spreads and interphase nuclei by double-color fluorescence in situ hybridization (FISH) using bacteriophage clones containing the human immunoglobulin gamma chain gene locus (Ig gamma) and a cosmid clone, CY24-68, containing VH segments. CY24-68 is more telomeric than Ig gamma, separated by approximately 1 megabase (Mb). FISH studies were performed on four patients with non-Hodgkin's lymphoma (NHL), one with acute lymphoblastic leukemia (ALL), one with plasma cell leukemia (PCL), and three cell lines. In each patient with t(8;14), t(14;18), and t(3;14), the signal of Ig gamma gene was observed on der(14) and that of CY24-68 at respective partner sites of these translocations, 8q24.1, 18q21.3, and 3q27. Interphase nuclei with a signal of Ig gamma clearly separated from that of CY24-68 were more frequently encountered in all of the patients (45% to 74%) than those in normal controls (4% to 5%). Even in cases where only interphase nuclei were available for FISH studies, 14q32 translocations are detected as shown in two patients each with NHL and t(11;14)-carrying PCL. In two cell lines, HS-1 derived from ALL carrying t(8;14) and FR4 derived from a plasmacytoma carrying a complex form of t(8;14), the signal of Ig gamma was observed at the breakpoint region 8q24.1 of the der(8) in addition to the der(14), indicating that translocation event occurred within the Ig gamma locus. Intense Ig gamma signal was found at the breakpoint region on the der(14)t(11;14) in HBL-2 derived from NHL, indicating amplification of the Ig gamma gene, and presumably the resultant chimeric DNA between Ig gamma and DNA sequences at 11q13. The present approach allowed us to unequivocally detect tumor-specific breakpoints of 14q32 translocations. Furthermore, interphase FISH provides a rapid diagnostic procedure to detect 14q32 translocations in B-cell malignancies.

Burkitt Lymphoma↗
PubMed1995

[Effect of the GH-PRL superfamily on circulating plasma insulin-like growth factor-1].

To elucidate the effects of growth hormone (GH), prolactin (PRL), and human placental lactogen (hPL) on the regulation of insulin-like growth factor (IGF-1), we compared plasma IGF-1 levels, the pattern of circulating IGF-1-IGF-binding protein complexes (IGF-1 complexes), and unsaturated binding protein (USBP) levels among 1) naturally growing Wistar rats at several developmental stages, 2) rats subcutaneously administered GH, and 3) hypophysectomized rats treated with each of the three hormones. We further evaluated the in vitro secretion of IGF-1 by primary cultured rat hepatocytes, following exposure to the hormones singly or in combination. Plasma IGF-1 and USBP levels were determined by radioimmunoassay and competitive radioassay, respectively. IGF-1 complexes were separated from plasma and culture medium by Sephadex G150 and HPLC gel-chromatography, respectively. The results were as follows. 1) In naturally growing rats, plasma IGF levels were low during fetal life and after birth until 28 days of age, and thereafter increased rapidly to reach an adult level by 35 days. At 35 days, the molecular distribution of IGF-1 switched from an infantile pattern (only 40Kd IGF-1 complex) to an adult form (IGF-1 complexes with both 40Kd and 150Kd proteins). In addition, 150Kd USBP became detectable after 28 days. 2) Administration of GH for 3 days to 13-day-old rats induced 150Kd USBP 9 days earlier than in controls, while plasma IGF-1 levels remained comparable throughout the period examined. 3) In the hypophysectomized rats, plasma IGF-1 levels decreased to approximately one fifth of those in untreated rats, accompanied by the disappearance of 150Kd USBP and 150Kd IGF-1 complex. However, when GH (but not PRL or hPL) was continuously administered for 72 hrs, plasma IGF-1 levels and the circulating profile of IGF-1 complexes were nearly restored to those in control rats. 4) Addition of GH (but not PRL) to the culture medium caused hepatocytes to secrete IGF-1, consisting of only the 40Kd IGF-1 complex. This effect was blocked by the simultaneous addition of hPL with GH. These findings indicate that, of the hormones analyzed, GH is the most important regulator of the plasma IGF-1 concentration and circulating complex forms during the developmental periods in rats, as is also thought to be the case in humans.

Animals↗
PubMed1995

Expression of glutamate (AMPA type) and gamma-aminobutyric acid (GABA)A receptors in the rat caudal trigeminal spinal nucleus.

The localization of GABAA receptor gamma 1 and gamma 2 subunits and the AMPA-type glutamate receptor subunits GluR1 and GluR2/3 were identified in the caudal trigeminal spinal tract nucleus (TNC) by immunohistochemistry using specific antibodies. The receptor species on the projecting neurons to the thalamus in TNC were also examined. A retrograde tracer, Fluoro-gold (FG), was injected into the thalamus, and the sections were simultaneously labeled with the antibodies. Injection of FG into the ventral posteromedial nucleus of the thalamus resulted in labeling of scattered neurons contralaterally in the TNC. Most of the neurons labeled by retrograde tracing also showed gamma 1- and gamma 2-like immunoreactivity, while many of the neurons containing FG lacked GluR1- and GluR2/3-like immunoreactivity. These findings show that neurons projecting to the thalamus from the TNC receive GABAergic input via GABAA receptors containing gamma 1 and gamma 2 subunits, while many neurons expressing the AMPA-type receptor did not project to the thalamus.

Animals↗
PubMed1995

UCN-01, an anti-tumor drug, is a selective inhibitor of the conventional PKC subfamily.

A selective PKC inhibitor, UCN-01, was shown to exhibit anti-tumor activity in vitro and in vivo. We investigated UCN-01 with respect to isozyme-specific PKC inhibition using purified recombinant or rabbit brain PKC isozymes, cPKC alpha, beta and gamma, nPKC delta, epsilon and eta, and a PKC zeta. Of the PKC isozymes examined, cPKC alpha was inhibited by UCN-01 most effectively (Ki = 0.44 nM), suggesting cPKC alpha is the prime candidate for the physiological target of UCN-01. The Ki values of UCN-01 estimated from Dixon plots for cPKC isozymes are approximately 1 nM, whereas the Ki values for nPKC isozymes are about 20 nM. Moreover, the Ki value for aPKC zeta is 3.8 microM. Thus, UCN-01 discriminates between PKC subfamilies. In addition, the inhibitory effects of staurosporine, H7, and calphostin C on aPKC zeta were examined and compared with those for cPKC alpha.

Alkaloids↗
PubMed1995

Non-competitive NMDA antagonists, FR115427 and MK801, enhance neuronal survival in primary culture.

Primary culture of cerebral cortical neurons from mouse embryo was treated with non-competitive N-methyl-D-aspartate (NMDA) receptor antagonists, FR115427 and MK801. Both FR115427 and MK801 at 1-10 microM promoted neuronal survival after 7 days cultivation, determined by calorimetric assay for acid phosphatase (AP) activity. FR115426, the (-) isomer of FR115427 also promoted neuronal survival. However, competitive NMDA antagonists, APH and CGS19755 did not show promotive effect on neuronal survival at up to 100 microM. Anti-NMDA activity of these compounds was evaluated using an NMDA-induced convulsion assay. The relative potency of anti-NMDA activity was CGS19755 > MK801 > APH > FR115427 > FR115426. These data suggest that the effects on neuronal survival by FR115427 and MK801 are independent of anti-NMDA activity.

Animals↗
PubMed1995

Behavioral studies on FR115427, a novel selective N-methyl-D-aspartate antagonist.

Behavioral and in vitro receptor binding methods were used to evaluate and compare the effects of FR115427 ((+)-l-methyl-1-phenyl-1,2,3,4-tetrahydroisoquinoline hydrochloride) with those of MK801, a non-competitive NMDA antagonist. FR115427 inhibited NMDA-induced convulsions in mice by intracerebroventrical(ICV) and systematic injection. FR115427 was found to be about ten times less potent than MK801. Furthermore, the inhibitory effect of FR115427 and MK801 on NMDA-induced convulsions was evaluated in time course studies in mice. MK801 exhibited a more sustained anticonvulsive activity than FR115427. In addition, PCP-like behaviors were examined in mice after ICV injection of these compounds. At the lowest dose FR115427 significantly increased locomotor activity, although the effect of this compound was about hundred times less potent than that of MK801. At higher dose a more complex pattern of behavior, e.g. head-movement and eventually ataxia was observed. In binding assays with rat brain membranes, FR115427 inhibited the binding of (3H)TCP (IC50 = 0.249 microM) and (3H)MK801 (IC50 = 0.312 microM) but did not inhibit the binding of (3H)CPP or (3H)glycine. These results suggest that FR115427 is a novel non-competitive NMDA antagonist that acts on a binding site located within the NMDA receptor associated ion channel.

Animals↗
PubMed1995

Mitral valve replacement with a collar-reinforced prosthetic valve for disrupted mitral annulus.

The mitral valve was replaced with a collar-reinforced prosthetic valve in 6 patients with a disrupted mitral annulus, in 3 because of infective endocarditis, including 2 patients with prosthetic valve endocarditis, in 2 because of a severely calcified mitral annulus, and in 1 who had previously undergone mitral valve replacement twice. Four patients had undergone prior mitral operations; these consisted of mitral valve replacement in 3 patients and mitral valve repair in 1. In all patients, the prosthesis was secured by double-layered sutures, with the first row of buttressed sutures passing through the leaflet or sutured to the left ventricular muscle and through the sewing cuff of the prosthetic valve. The second row of running sutures was then placed through an extended annular equine pericardial cuff of the prosthetic valve and the supraannular left atrial wall. In 2 patients, all chordae tendineae were preserved to maintain annulopapillary muscle continuity. All patients survived and have remained well for a mean of 22.3 months. There has been no prosthetic valve dehiscence, except for minimal paraprosthetic leakage in 1 patient. These results demonstrate that mitral valve replacement in patients with a disrupted mitral annulus can be successfully accomplished with a collar-reinforced prosthetic valve.

Aged↗
PubMed1995

Pituitary apoplexy after pituitary function test: a report of two cases and review of the literature.

BACKGROUND: Although most of pituitary apoplexy occur spontaneously, some precipitating factors have been reported. We experienced two cases of pituitary apoplexy after a pituitary function test. METHODS: In order to clarify the causal relation between the pituitary function test and apoplexy, we presented our two cases and reviewed 20 cases in the literature. RESULTS: (Case 1) A 48-year-old man with a pituitary macroadenoma received an injection of 500 micrograms thyrotropin-releasing hormone (TRH), 100 micrograms gonadotropin-releasing hormone (GnRH), and 0.1U/kg insulin as a preoperative test of pituitary function. Fifteen minutes later, he complained of diminished vision and headache. (Case 2) A 54-year-old man with a large cystic adenoma had an administration of 500 micrograms TRH and 100 micrograms GnRH. Ten minutes later, he complained of blurring of his left eye and headache. Although, in both cases, CT scans showed neither intratumoral hemorrhage nor infarction, the surgical specimen showed necrotic and hemorrhagic adenoma. The patients made excellent clinical recoveries after surgical decompression. Twenty-two reports including our two cases were reviewed. In 15 cases (68%), TRH was associated with apoplectic events and seemed to be the agent most likely to have an etiologic role because of its vasoactive properties. Eighteen patients (82%) had pituitary macroadenomas with suprasellar extension. In 72% of 18 surgical cases, some recovery of visual function was obtained. CONCLUSIONS: An apparent relationship between the test and the apoplectic events raises the possibility of the development of pituitary apoplexy after a pituitary function test. Unless there is a specific indication, pituitary function test should be avoided especially in patients with a large pituitary tumor.

Adenoma↗
PubMed1995

Coexpression of trk family members and low-affinity neurotrophin receptors in rat dorsal root ganglion neurons.

We examined the colocalization of trk family and low-affinity neurotrophin receptor (LANR) mRNAs by means of in situ hybridization histochemistry in rat dorsal root ganglion (DRG) neurons. About 35-40%, 5%, and 15-20% of DRG neurons were positive for trkA, trkB, and trkC mRNAs, respectively. Each member of the trk family was coexpressed with LANR. The trkB mRNA-expressing neurons essentially lacked trkA and trkC mRNAs, and most of trkA and trkC mRNAs-expressing neurons (85-90%) belonged to different subpopulations, suggesting that they are involved in different functions.

Animals↗
PubMed1995

Simultaneous monitoring of the seizure-related changes in extracellular glutamate and gamma-aminobutyric acid concentration in bilateral hippocampi following development of amygdaloid kindling.

We simultaneously monitored the seizure-related changes in extracellular hippocampal glutamate (Glu) and gamma-aminobutyric acid (GABA) concentration in brain dialysates in order to clarify the role of Glu and GABA in the development of kindling. Brain dialysates were collected every 5 min from 10 min prior to 80 min after stimulus in the three developing conditions consisting of pre-kindling state, stage 3 (C-3), and five consecutive stage 5 (5*C-5) following kindling in the same rat. Extracellular Glu level increased rapidly, lasting for only 5 min after stimulus. The post-stimulus ratio of Glu increase in partially kindled rats (C-3) was 2.5-3.5 times of the baseline, and in fully kindled rats it was about 5 times of the baseline. Extracellular GABA concentration enhanced gradually, reaching a plateau level at 15-20 min and lasting for several hours after stimulus at each stage. The enhancement of GABA level was about 1.5 times of the baseline in partially kindled stage, and was about 2.5 times of the baseline in fully kindled stage. There was no significant difference between the two hemispheres with respect to either the time-course or the magnitude of Glu and GABA increase respectively. These data show that progressive, transient and stimulus-induced enhancement of extracellular Glu levels combined with long-lasting elevation of extracellular GABA levels in the bilateral ventral hippocampi results in imbalance between the excitatory and inhibitory neuronal systems, causing excessive propagation of seizure activity, culminating in the secondary generalized seizure of amygdaloid kindling.

Amygdala↗
PubMed1995

Neurofibromatosis 1 gene (NF1) mutation is a rare genetic event in myelodysplastic syndrome regardless of the disease progression.

Neurofibromatosis 1 gene (NF1) is a tumor suppressor gene and the product of which down-regulates Nras protein by its GTPase activating protein-related domain (NF1-GRD). Although the incidence of NF1 mutation was reported to be rare in the chronic phase of myelodysplastic syndrome (MDS), there have been no previous reports on its configuration in patients showing the disease progression. We examined NF1 in 50 patients with MDS including 9 who had progressed to more advanced stages and 16 to acute leukemia. Six patients had an Nras mutation. We carried out allele specific restriction analysis (ASRA) to detect a mutation at the first nucleotide A of codon 1423 (AAG), a mutational hot spot. We also employed a polymerase chain reaction mediated single strand conformation polymorphism (PCR-SSCP) method to confirm the result of ASRA and to detect a point mutation in other sequences of FLR exon. In consequence, ASRA disclosed wild type configuration and PCR-SSCP showed no aberrant band in any sample examined whether the samples harboured an Nras mutation or not. We conclude that NF1 mutation does not play a crucial role in the development and the progression of MDS.

Base Sequence↗
PubMed1995

Coexistent myelodysplastic syndrome and non-Hodgkin lymphoma. Report of a case and review of the literature.

The patients with a hematopoietic neoplasm can develop myelodysplastic syndrome following chemotherapy. We report herein a case of non-Hodgkin B-cell lymphoma and refractory anemia with ringed sideroblasts. Absence of the preceding chemotherapy establishes the true coincidence of the two disorders. We review 25 similar cases reported in the last 11 years and discuss the possible etiology of coexistence.

Aged↗
PubMed1995

Early and late results of repair of tetralogy of Fallot with subarterial ventricular septal defect. A comparative evaluation of tetralogy with perimembranous ventricular septal defect.

Between November 1966 and December 1990, 511 pediatric patients with tetralogy of Fallot underwent corrective operation at Tenri Hospital. There were 78 patients with subarterial ventricular septal defect. Mean age at repair was 5.6 +/- 3.3 years. The method of right ventricular outflow tract reconstruction was simple infundibulectomy in 14 patients, right ventricular ventricular outflow patch in 36, and transannular patch in 28. There were 7 (9.0%) early deaths as a result of low cardiac output syndrome and acute renal failure. The pressure ratio of the right ventricle to the left ventricle was 0.62 +/- 0.18 during the early postoperative catheterization. Follow-up was achieved for 442.6 patient-years and ranged from 0.5 to 27 years, with an average of 8.5 +/- 6.7 years. There were three late deaths (2 cardiac and 1 noncardiac). Actuarial survival was 94.8% +/- 4.0% at 20 years. Catheterization during late follow-up (6.8 +/- 4.7 years after repair) was done in 53 patients and the pressure ratio of the right ventricle to the left ventricle was 0.48 +/- 0.21. Fifteen patients underwent subsequent operation because of residual lesions, including ventricular septal defect in four patients, pulmonary stenosis in nine, combined ventricular septal defect and pulmonary stenosis in one, and pulmonary regurgitation in one, with no mortality. Actuarial rate of freedom from reoperation was 71.1% +/- 8.0% at 10 years and 58.8% +/- 16.8% at 20 years. Patients with tetralogy and subarterial ventricular septal defect were more likely to have the development of residual obstruction at the level of the pulmonary valve anulus after repair than were those with tetralogy and perimembranous ventricular septal defect.

Abnormalities, Multiple↗
PubMed1995

New aspects of cell biology in osteosarcoma.

Among the solid tumors of childhood and adolescence, osteosarcoma (OS) represents the most prominent example of efficient aggressive chemotherapy with secondary surgical therapy. A specific subclassification of the tumor is indispensable and must include recent results of cell biology. The co-distribution of different collagen types I-VI reflects the diverse differentiation of osteosarcoma cells, supporting the concept of a pluripotent mesenchymal cell to be the stem cell of the tumor. In contrast, osteonectin (SPARC) may not be considered as a reliable marker for osteosarcoma. The experience of special proteins being secreted by osteosarcoma cells is rather limited. Detailed molecular biological studies are still lacking. A loss of alleles on chromosome 17, particularly in the defined region 17p 13, can be observed in more than 75% of all OS, suggesting the contribution of a tumor suppressor gene, p53, located in that region. It is a 53 kd nucleophosphoprotein binding the major transforming protein, the large T antigen of Simian Virus 40. Immunohistological results showed positive staining with the antibody Pab 240 in 13 of 18 cases. In one osteoblastic OS, a novel splice mutation resulting in a fusing of exon 5 directly to exon 7 was detected. RB1 gene is also of major importance for the tumorigenesis of OS. The multidrug resistance (mdr) is associated with a membrane-bound channel-forming transport protein, the P-glycoprotein. It is a conserved plasma membrane component of about 170 kd. Both the human isoforms mdr 1 and mdr 3 are localised in the long arm of chromosome 7.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Neoplasms↗