Isospin character of low-lying states in 56Fe.
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Journal Article↗
Biomedical subjects
T Yamagata
Publications and source records attributed to T Yamagata.
A novel interferon regulatory factor family transcription factor, ICSAT/Pip/LSIRF, that negatively regulates the activity of interferon-regulated genes.
We have isolated a novel cDNA clone encoding interferon (IFN) consensus sequence-binding protein in adult T-cell leukemia cell line or activated T cells (ICSAT); this protein is the human homolog of the recently cloned Pip/LSIRF. ICSAT is structurally most closely related to the previously cloned ICSBP, a member of the IFN regulatory factor (IRF) family of proteins that binds to interferon consensus sequences (ICSs) found in many promoters of the IFN-regulated genes. Among T-cell lines investigated, ICSAT was abundantly expressed in human T-cell leukemia virus type 1 (HTLV-1)-infected T cells. When the HTLV-1 tax gene was expressed or phorbol myristake acetate-A23187 stimulation was used, ICSAT expression was induced in Jurkat cells which otherwise do not express ICSAT. When the binding of ICSAT to four different ICSs was tested, the relative differences in binding affinities for those ICSs were determined. To study the functional role of ICSAT, we performed cotransfection experiments with the human embryonal carcinoma cell line N-Tera2. ICSAT was demonstrated to possess repressive function over the gene activation induced by IFN stimulation or by IRF-1 cotransfection. Such repressive function is similar to that seen in IRF-2 or ICSBP. However, we have found that ICSAT has a different repressive effect from that of IRF-2 or ICSBP in some IFN-responsive reporter constructs. These results suggest that a novel mechanism of gene regulation by "differential repression" is used by multiple members of repressor proteins with different repressive effects on the IFN-responsive genes.
Amino Acid Sequence↗
Neuromuscular junctions of the posterior cricoarytenoid muscle in the adult rat: a scanning electron microscopical study.
Neuromuscular junctions in the posterior cricoarytenoid (PCA) muscle of the adult rat larynx were examined by scanning electron microscopy. Two types of focal junctions were characterized by the nerve endings with terminal varicosities or terminal buttons and by the subneural apparatuses with a group of cup-like depressions (2-5 microns in diameter), not labyrinthine gutters. One type of the subneural apparatuses consisted of a large number (more than 20) of depressions with predominantly slit-like junctional folds. The other type was characterized by a small number (about 10) of depressions with a few junctional folds. From the relative proportions of the two types of muscle fibers and subneural apparatuses in the rat PCA muscle, we suggest that the Type II fibers have the apparatus consisting of numerous small depressions with many junctional folds, while that of the Type I fibers consists of a small number of depressions with a smaller number of junctional folds. It is suggested that the structural differences of the subneural apparatus reflect different types of muscle fibers.
Animals↗
Impaired endothelium-dependent vasodilation of coronary resistance vessels in hypercholesterolemic patients.
To determine the relationship between hypercholesterolemia and the endothelial function of coronary resistance vessels, we studied the changes in coronary blood flow (CBF) in response to acetylcholine, an endothelium-dependent vasodilator, and adenosine, an endothelium-independent vasodilator, in patients with hypercholesterolemia (n = 17) and in control patients (n = 17). All patients had normal epicardial coronary arteries. Serial 2-min infusions of acetylcholine, at 3 micrograms/min and 30 micrograms/min, caused a dose-dependent increase in CBF in each group. The acetylcholine-induced maximal increases in CBF were inversely correlated with the serum cholesterol level (r = -0.55, p < 0.01), and were significantly smaller in the hypercholesterolemic patients than in control patients. However, the adenosine-induced increases in CBF were similar in the two groups. These results suggest that the endothelium-dependent vasodilation of resistance vessels is lessened in patients with hypercholesterolemia even before the formation of atherosclerotic stenotic lesions in epicardial coronary arteries, and that hypercholesterolemia impairs endothelium-dependent vasodilation of coronary resistance vessels.
Acetylcholine↗
Coronary segmental responses to acetylcholine in patients with hypercholesterolemia.
We investigated coronary segmental response to intracoronary acetylcholine (ACh) in 19 patients with hypercholesterolemia and 18 patients with normal cholesterol levels. All patients had atypical and chest pain and angiographically normal coronary arteries. After baseline angiography, ACh (3 and 30 micrograms/min) was infused into the left coronary artery, followed by infusion of nitroglycerin. Percent changes in diameter of the proximal, middle, and distal segments of the left coronary arteries were measured by quantitative angiography. In the normocholesterolemic group, 3 micrograms/min of ACh produced significant coronary vasodilation in the distal segments (+8.2 +/- 2.6%, p < 0.005), while 30 micrograms/min did not cause any changes. In the hypercholesterolemic group, 30 micrograms/min of ACh caused significant coronary vasoconstriction in the middle and distal segments (-7.2 +/- 1.9% and -6.2 +/- 1.9%, p < 0.001 and p < 0.01, respectively), while 3 micrograms/min caused no changes. In each group, vasodilator responses to nitroglycerin in the middle and distal segments were significantly greater than those in the proximal segments (p < 0.001). Our results suggest that impaired endothelial function may be evaluated more effectively in the distal coronary segments in patients in the early stage of epicardial coronary atherosclerosis attributable to hypercholesterolemia.
Acetylcholine↗
Isolation of a cosmid clone corresponding to an inv(21) breakpoint of a patient with transient abnormal myelopoiesis.
Transient abnormal myelopoiesis (TAM) is a leukemoid reaction occurring occasionally on Down syndrome (DS) newborn infants. It has been hypothesized that "disomic homozygosity" in 21-trisomic cells plays an important role in the genesis of TAM, and the putative TAM gene was suggested to be mapped at a 21q11 region. We encountered a DS-associated TAM infant with a 47,XY,inv(21)(q11.1q22.13),+inv(21)(q11.1q22.13) karyotype. On the basis of another presumption that in this patient the putative TAM gene is disrupted by the break, we tried to isolate a breakpoint DNA. FISH analysis with cosmid clones corresponding to various sequence-tagged-site (STS) markers mapped at around 21q11.1-q11.2, we confirmed that the proximal breakpoint of the inv(21) was located between two STSs, G51E07 and D21S215, the latter locus being consistent with the previous tentative mapping. After construction of a cosmid contig encompassing between the two markers, we have isolated a cosmid clone corresponding to the proximal breakpoint of the inversion. This breakpoint was located near a previously identified duplicated region that is homologous to the sequence at 21q22.1. The isolated cosmid clone is useful for analysis of other TAM patients and for a search for a transcript at or flanking the breakpoint.
Adult↗
[Coronary artery bypass grafting surgery without cardiopulmonary bypass in a patient with calcified aorta].
Coronary artery bypass surgery in a 67-year-old male with severe calcified ascending aorta was performed without cardiopulmonary bypass under beating heart, utilizing the left internal thoracic artery graft. No neurological complication was observed and postoperative angiogram showed good graft patency. We think coronary revascularization without cardiopulmonary bypass can be one of the safe and reliable methods to avoid complications associated with aortic cross clamping and aortic cannulation with severely calcified aorta.
Aged↗
[Landau-Kleffner syndrome: relationship between aphasia and electroencepharographic changes].
The relationship between aphasia and electroencephalogram (EEG) findings was studied in 2 patients with Landau-Kleffner syndrome. The appearance of diffuse spike and wave complexes almost always preceded the exacerbation of aphasia. Prior to the improvement of aphasia, EEG abnormality localized into the temporal region, and subsequently disappeared.
Aphasia↗
[The clinicopathological characters and prognostic factors of small peripheral lung cancer measuring 3 cm or less in diameter].
Of the 183 patients with primary lung cancer treated at our hospital with small peripheral lung cancers of 3 cm or less in diameter: 16 had tumors up to 1 cm, 23 had tumors of 1-1.5 cm, 43 had tumors of 1.5-2 cm, and 101 had tumors of 2-3 cm in diameter. These tumors comprised 134 adenocarcinomas, 31 squamous cell carcinomas, 6 adenosquamous carcinomas, 4 small cell carcinomas, 2 large cell carcinomas and 6 carcinoids. The tumor classification was 134 n0, 20 n1, and 29 n2 tumors. As tumor size is smaller, n0 tumors, p0 + p1 tumors and ly0 tumors are significantly increased. All tumors of up to 1 cm in diameter exhibited no node or intrapulmonary metastases and never resulted in the death of the patients due to lung cancer: thus good prognoses may be expected in such cases. In tumors larger than 1 cm in diameter, node or intrapulmonary metastases are increased and 5-year survival rates are decreased. In multivariate analysis the most effective factor on prognosis is node metastasis. For better post-operative prognosis, we may have to detect and resect peripheral lung cancers in the stage of tumor size of up to 1.5 cm in diameter, because node metastases are rare in these small tumors.
Adenocarcinoma↗
Hepatocyte growth factor specifically expressed in microglia activated Ras in the neurons, similar to the action of neurotrophic factors.
Hepatocyte growth factor (HGF) mRNA and its receptor (c-Met) mRNA were detected in the fetal and adult rat brain. Expression of c-Met mRNA was increased after birth. HGF mRNA was preferentially expressed in the microglia of the rat brain, while c-Met mRNA was expressed in neurons as well as astrocytes and microglia. Most of the neurons were c-Met positive, and HGF stimulated tyrosine phosphorylation of c-Met (140-kDa) in the neurons. HGF as well as bFGF also activated Ras in the neurons. These results suggest that HGF plays a biological role as one of the neurotrophic factors in the brain.
Animals↗
Analysis of glycosaminoglycan-degrading enzymes by substrate gel electrophoresis (zymography).
Substrate gel electrophoresis is of use for detecting minute amounts of hyaluronidase (HAase). In substrate gel electrophoresis, hyaluronan (HA) is impregnated in a gel. To determine the presence of degradation enzymes for other glycosaminoglycans (GAGs), the sizes of whose molecules are much smaller than that of HA, we have developed a technique by which chondroitin sulfate (CS) is chemically modified by introducing an allyl group at the reducing end for its immobilization in the gel. Enzymes with CS-degrading activity were detected on a CS-copolymerized gel in the presence or absence of sodium dodecyl sulfate. The smallest amount of chondroitinase ABC and HAase was found to be 8 microU and 0.35 mU, respectively. By zymography using HA-impregnated and modified CS-copolymerized gels human serum HAase has been shown to consist of at least two isoforms each with its own substrate specificity. Using this method, uterine tumor tissue has been shown to secrete a novel HAase which degrades HA at neutral pH, but not CS at any pH. This method was also confirmed applicable to other GAGs for determining individual GAG-degrading enzymes. In future research, it will be used to examine the regulation of each GAG species in tissue.
Acrylamide↗
Cosmid assembly and anchoring to human chromosome 21.
A human chromosome 21-specific cosmid library from the Lawrence Livermore National Laboratory has been analyzed by two complementary methods, fingerprinting and hybridization; 40% coverage of the entire chromosome 21 has been achieved. To prepare a contig pool, approximately 9300 cosmid clones randomly selected from the library were fingerprinted and automatically assembled into 467 overlapping sets by the fluorescence-tagged restriction fragment method. The average size of the overlapping sets was 9.5 cosmids with minimal tiling paths consisting of 5.4 cosmids with a 10-kb extension each. However, as many as 10% of overlaps within members were estimated to be false. For regional localization, we hybridized gridded arrays of cosmids with inter-Alu-PCR probes obtained from YAC clones and somatic cell hybrids and assigned 592 cosmids to 26 subregions of 21q. Of these, 371 clones were incorporated into 139 contigs, anchoring the total 1864 cosmids to the subregion. The remaining 221 clones were mapped as orphans. To correlate the cytogenetic, YAC, and cosmid maps on 21q, the translocation breakpoints of the chromosomes contained in the somatic cell hybrids were mapped with respect to the STS content of the YACs. From the gene cluster regions, 176 ribosomal and 25 alphoid clones were isolated by hybridization. Together, these sets of anchored contigs and cosmids will provide a valuable resource for construction of a high-resolution map and for isolation of genes of interest from chromosome 21.
Animals↗
Nucleotide diversity of mitochondrial DNAs between the swamp and the river types of domestic water buffaloes, Bubalus bubalis, based on restriction endonuclease cleavage patterns.
Cleavage patterns of mitochondrial DNAs (mtDNAs) by 15 restriction endonucleases were analyzed for 10 swamp and 13 river types of domestic water buffaloes. Digestions with nine enzymes exhibited polymorphisms giving two or three kinds of cleavage patterns. Five mtDNA types were identified, three types in the swamp buffaloes of the Philippines, Vietnam, and Indonesia (S-types) and two types in the river buffaloes of Bangladesh and Pakistan (R-types). Nucleotide diversities ranged from 0.2 to 0.6% within the S- and R-types and from 1.9 to 2.4% between the R-types and the S-types. These values indicated that R-type and S-type mtDNAs differentiated at the subspecific level of other mammalian species reported. The possibility of polyphyletic domestication in different places is discussed for the origin of two distinct types of domestic water buffaloes.
Animals↗
Production of human monoclonal antibodies to i blood group by EBV-induced transformation: possible presence of a new glycolipid in cord red cell membranes and human hematopoietic cell lines.
To study the differentiation-associated glycolipid two anti-i mAb producers, GL-1 and GL-2, were established from the combination of EBV-induced transformation of normal PBL and immune lysis of fluorescent dye-trapped liposome-containing bovine i-active glycolipid. The mAb GL-1 reacted with both sialosylparagloboside and pentahexosyl ceramide and the bovine i-active glycolipid whereas mAb GL-2 reacted only with the bovine i-active glycolipid in LILA. Both mAbs cold-agglutinate human cord red cells but not adult red cells. However, unexpectedly, the majority of the reactivity of these mAbs in human cord red cells on TLC was not identical to the i-active glycolipid. The GL-1 antigenic substance is considered to be a glycolipid distinct from the i-active glycolipid because the immunoreactivity was canceled with endoglycoceramidase which cleaves a linkage between the oligosaccharide and ceramide. Based on complement cytolysis with the mAb, 15 hematopoietic cell lines and normal peripheral lymphocytes were screened for susceptibility to the mAbs. A Burkitt lymphoma cell line, Ramos, was most sensitive among those tested, and BJA-B, Daudi, Namalwa in the B cell lines, TALL-1, Jurkatt in the T-cell lines and HL-60 in the non-lymphoid cell lines were sensitive whereas normal lymphocytes or other 8 cell lines were not. An immunoreactive spot with the same Rf with cord red cells was also detected in sensitive cell lines. The possible presence of a new glycolipid antigen determined from the mAb and related to the differentiation of hematopoietic cells was speculated.
Antibodies, Monoclonal↗
The hydrolysis of cell surface glycosphingolipids by endoglycoceramidase reduces epidermal growth factor receptor phosphorylation in A431 cells.
This paper presents a new method to evaluate the biological significance of glycosphingolipids (GSLs) using a GSL-specific enzyme, endoglycoceramidase (EGCase), by which GSL-sugar chains are removed from the cell surface of living cells. In this report, the effects of EGCase on epidermal growth factor (EGF)-dependent tyrosine-specific EGF receptor (EGFR) phosphorylation of A431 cells are described. After treatment of A431 cells with EGCase II (20 mU/ml) in the presence of the activator for 12 h, all acidic GSLs tested were reduced to approximately 70% of control, but no hydrolysis occurred on Gal alpha 1,4Gal beta 1,4Glc beta 1,1Cer (Gb3Cer) and GalNAc beta 1,3Gal alpha 1,4Gal beta 1,4Glc beta 1,1Cer (Gb4Cer). In plasma membrane fractions of A431 cells, the reduction of gangliosides by EGCase II was found to be much faster than that of intact cells and reached 54.8% reduction of total gangliosides after 2 h incubation with the enzyme. EGF-dependent phosphorylation of EGFR of A431 cells was inhibited by the reduction of cell surface GSLs by EGCase when either intact A431 cells or their plasma membrane fractions were used, while EGF binding to their receptors was not changed. Neither hydrolysis of cell surface GSLs nor reduction of EGFR phosphorylation occurred when A431 cells were incubated with the activator or EGCase alone. The exogenous addition of ceramides or sphingosines, and treatment of cell membranes with sphingomyelinase, had no effect on the EGFR phosphorylation of purified membrane fractions, while the inhibitory effect of EGCase II on EGFR phosphorylation was restored by the addition of GM3-sugar chains, but not by lactose or sialic acid.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acids↗
Transformation into acute basophilic leukaemia in a patient with myelodysplastic syndrome.
We describe a patient with basophilic leukaemia following a 2-year period with myelodysplastic syndrome (refractory anaemia). The marrow showed 59.4% of blasts with 25.0% of mature and immature basophils. The leukaemic blasts contained granules, positively stained with toluidine blue but negative for peroxidase. The basophilic differentiation was confirmed by ultrastructural analysis demonstrating immature basophil granules. In addition, a morphological transition from immature blasts to more mature basophils was observed. Immunophenotypic analysis of blasts and basophils showed positive for CD5, CD7, CD13, CD33 and CD34. Cytogenetic investigation showed an abnormal karyotype, 46,XY,del(5)(q31q35), in 11% of the cells examined when the initial diagnosis of refractory anaemia was made. However, expansion of the same clone up to 100% was observed concomitantly with transformation to basophilic leukaemia.
Anemia, Refractory↗
Of the GATA-binding proteins, only GATA-4 selectively regulates the human interleukin-5 gene promoter in interleukin-5-producing cells which express multiple GATA-binding proteins.
Interleukin-5 (IL-5) is produced by T lymphocytes and known to support B-cell growth and eosinophilic differentiation of the progenitor cells. Using ATL-16T cells which express IL-5 mRNA, we have identified a region within the human IL-5 gene promoter that regulates IL-5 gene transcription. This cis-acting sequence contains the core binding motif, (A/T)GATA(A/G), for GATA-binding family proteins and thus suggests the involvement of this family members. In this report, we describe the cloning of human GATA-4 (hGATA-4) and show that hGATA-4 selectively interacts with the -70 GATA site within the IL-5 proximal promoter region. By promoter deletion and mutation analyses, we established this region as a positive regulatory element. Cotransfection experiments revealed that both hGATA-4 and phorbol-12-myristate-13-acetate (PMA)-A23187 stimulation are necessary for IL-5 promoter activation. The requirement for another regulatory element called CLE0, which lies downstream of the -70 GATA site, was also demonstrated. ATL-16T cells express mRNAs of three GATA-binding proteins, hGATA-2, hGATA-3, and hGATA-4, and each of them has a potential to bind to the consensus (A/T)GATA(G/A) motif. However, using ATL-16T nuclear extract, we demonstrated that GATA-4 is the only GATA-binding protein that forms a specific DNA-protein complex with the -70 GATA site. An electrophoretic mobility shift assay with extracts of COS cells expressing GATA-binding proteins showed that GATA-4 has the highest binding affinity for the -70 GATA site among the three GATA-binding proteins. When the transactivation abilities were compared among the three, GATA-4 showed the highest activity. These results demonstrate the selective role of GATA-4 in the transcriptional regulation of the IL-5 gene in a circumstance where multiple members of the GATA-binding proteins are expressed.
Amino Acid Sequence↗
Genetic variation and geographic distribution on the mitochondrial DNA in local populations of the musk shrew, Suncus murinus.
The musk shrew (Suncus Murinus) is widely distributed throughout Asia and East Africa. The mitochondrial DNA (mtDNA) of this species was analyzed in individuals from 31 local populations in nine Asian countries and Mauritius, using 17 restriction endonucleases. Although fourteen and nine mtDNA haplotypes were detected from Bangladesh and Nepal, respectively, one to four haplotypes were found in each Southeast Asian country, and one common haplotype existed in Japan, Philippines, Vietnam, Thailand and Indonesia. Clustering analysis of mtDNA haplotypes classified shrew populations to three groups--continental group (Bangladesh and Nepal), islands' group (insular countries and Vietnam) and Malay group. The average nucleotide diversity among these three groups was calculated to be about 3.5%. These results indicate that the origin of feral populations in this species might be old and their population sizes are extremely large in the continent, and suggest a rapid spread of this animal throughout the islands. Although we have not shown yet an evidence of close relationships between islands' and continental mtDNA haplotypes, it is likely that the musk shrew had migrated from the continent in South Asia to the islands in Southeast Asia recently.
Animals↗