Biomedical subjects

Y Kishimoto

Publications and source records attributed to Y Kishimoto.

At least 163 records · Page 9Linked to original sources

PubMed1992

Detection of a common mutation of the catalase gene in Japanese acatalasemic patients.

Acatalasemia was one of the earliest described genetic enzyme defects. In 1990, a causal point mutation (a splicing mutation) was first reported in a Japanese patient with acatalasemia. In the present study, the polymerase chain reaction and single-strand conformation polymorphism analysis were used to determine whether the same point mutation was present in unrelated Japanese patients. The subjects studied were the previously examined acatalasemic female, her brother, who is hypocatalasemic, and two other unrelated acatalasemic patients. A single G to A point mutation at the fifth position of intron 4, identical to that previously found, was present in all the studied patients. This finding strongly suggests that only a single mutated allele has spread in the Japanese population.

Acatalasia↗

PubMed1992

Distribution of saposins (sphingolipid activator proteins) in tissues of lysosomal storage disease patients.

Saposins are a group of small glycoproteins derived from a single precursor protein, prosaposin. Each of the four saposins are involved in lysosomal hydrolysis of various sphingolipids. Our recent investigations have shown that saposins accumulate in tissues of several lysosomal storage diseases patients, including those with Tay-Sachs disease and Gaucher disease. To obtain insight into the mechanism of accumulation and its pathological role, the subcellular distribution of saposins in brain from Tay-Sachs disease and in spleen of Gaucher disease were compared with that of GM2 ganglioside and glucocerebroside, respectively. In both Tay-Sachs brain and Gaucher spleen, saposins were found predominantly in light-density fractions while most of the GM2 ganglioside and glucocerebroside, respectively, were found in heavy-density fractions. These studies indicate that saposins that accumulate in these pathological tissues are not tightly associated with GM2 ganglioside or glucocerebroside.

Brain↗

PubMed1992

Acute myelomonocytic leukemia with marrow eosinophilia showing 5q- and 16q22 mosaicism.

We report an 82-year-old Japanese female with acute myelomonocytic leukemia with dysplastic marrow eosinophilia (FAB M4Eo) exhibiting a partial deletion of the long arm of chromosome 5, del(5)(q13q31) and a derivative chromosome 16 with a breakpoint at band 16q22, in addition to 5q-. The patient had a history of a preleukemic phase for several months with marked dysplasia in trilineage marrow cells, in addition to leukemic features compatible with M4Eo. These findings strongly suggested that the leukemic cells in this case were derived from a preleukemic clone with a del(5q).

Aged↗

PubMed1992

Morphological features of cat thalamo-parietal projection fibers investigated by PHA-L immunohistochemistry and electron microscopy.

Thalamo-parietal fibers originating from the ventroanterior-ventrolateral (VA-VL) complex in the cat were labeled with Phaseolus vulgaris leucoagglutinin (PHA-L) and examined by light and electron microscopy. PHA-L (2.5% aqueous solution) was injected iontophoretically through micropipets with anodal current pulses into the VA-VL complex. PHA-L-labeled terminals were distributed in the lateral and the suprasylvian gyri in the superficial and deep cortical layers. In layer I, horizontal varicose fibers and terminals were conspicuous in the upper one-third and were widely distributed. In the deeper cortical layers (layers III-V), varicose fibers and terminals were detected in moderate numbers. Electron microscopic examination revealed that the labeled terminals formed asymmetrical synapses on the dendritic spines of spiny neurons. These morphological findings appeared to be consistent with our previous intracellular recordings in this cortex.

Animals↗

PubMed1992

Production and characterization of a monoclonal antibody to human saposin C.

A murine IgG1 monoclonal antibody, termed 68-12, was produced against purified human saposin C. Immunoprecipitation and binding analysis indicated that the antibody reacted only with saposin C. Dot blotting and Western analysis demonstrated that antibody 68-12 also reacted with prosaposin and a higher molecular weight protein(s) in murine spleen and cerebral grey matter. Solid phase competitive radioimmunoassay against 125I labeled saposin C (0.25 micrograms/ml) showed no cross reactivity for saposin A, B and D up to 15 micrograms/ml. At a concentration of 50 micrograms/ml saposin A, B and D cross reacted 21, 1.5, and 49% respectively. Monoclonal antibody 68-12 appears to have potential utility in the purification, detection and quantitation of human saposin C and its precursor.

Animals↗

PubMed1992

F-SSCP: fluorescence-based polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis.

A fluorescence-based method for polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis, F-SSCP, was developed in which the target sequence is amplified by the PCR using fluorescent primers. The amplified products are then heat-denatured and applied to a water-jacket controlled gel in an automated DNA sequencer. The separated strands are detected as laser-excited fluorescence at the bottom of the gel, and mutations are detected as shifts in the position of the peaks in the fluorogram. The system does not involve radioactivity, and the conditions of electrophoresis are more strictly controlled than in the previous system, which relied on ambient air-cooling to maintain the gel at a constant temperature. The nature of the output data allows direct quantitative interpretation, and so the relative abundance of each allele in a mixture of two or more alleles can easily be estimated. The application of F-SSCP for detection of mutations and loss of heterozygosities of p53 in tumor tissues is reported.

Base Sequence↗

PubMed1992

Detection of DNA aberrations in human cancers by single-strand conformation polymorphism analysis of polymerase chain reaction products.

We have developed a simple, sensitive method, single-strand conformation polymorphism (SSCP) analysis, to detect a single nucleotide substitution in a DNA fragment amplified and labeled by the polymerase chain reaction (PCR). Mobility shift of single-stranded DNAs due to their specific conformations on non-denaturing polyacrylamide gel electrophoresis can reveal DNA aberrations. By the PCR-SSCP analysis of DNAs from surgical specimens of human cancers, mutated ras genes (17%) and aberrations of tumor suppressor p53 gene (53%) including loss of one of the two alleles and a mutation in the remaining allele were detected in lung carcinomas and aberrations of both of the p53 and retinoblastoma (RB) genes were detected exclusively in advanced hepatocellular carcinomas.

Carcinoma, Hepatocellular↗

PubMed1992

Fetal and neonatal excretion of free and conjugated ritodrine.

The ability of the human fetus and neonate to conjugate and excrete ritodrine, a beta 2-sympathomimetic drug, was investigated. Free and conjugated ritodrine concentrations in the plasma, amniotic fluid and urine were measured in 11 mother-infant pairs, to whom intravenous ritodrine had been administered before elective cesarean section at term. Ritodrine was determined by HPLC with electrochemical detection. At delivery, conjugated ritodrine values were significantly higher than those for the free form in maternal and fetal plasma. There were significant positive correlations between the concentrations in the maternal and umbilical vein plasma for both free and conjugated ritodrine. In the amniotic fluid, the total ritodrine concentrations were much higher than those in the fetal plasma, the conjugated form accounting for 90.2% of the total. Furthermore, the percentages of conjugated ritodrine in the amniotic fluid and neonatal urine were significantly higher than the percentage in the maternal urine on the day of birth. In the neonatal urine, the concentrations of free and conjugated ritodrine decreased rapidly after birth as did those in the maternal urine, on day 3 postpartum being less than 2% of the values on the day of parturition. These results indicate that the fetus at term is capable of forming conjugated metabolites of ritodrine and of excreting free and conjugated ritodrine in its urine.

Amniotic Fluid↗

PubMed1992

[Construction of a multiple mood scale].

A self-report instrument to measure multiple mood states was constructed. Six hundred and forty-eight Japanese affect adjectives were collected and divided into two lists. Japanese undergraduates totaling 1,254 rated each adjective in the list on a 4-point intensity scale to assess their momentary mood states. Factor analyses revealed 131 items with high loading on extracted major factors. The new list of these 131 items was rated three times by undergraduates totaling 1,768 and was factor analysed. Throughout the factor analyses, eight factors emerged with consistent reliability. Finally, 80 items highly loaded on these factors were selected to construct eight 10-item mood scales. These scales were called Depression (Anxiety), Hostility, Boredom, Liveliness, Well Being, Friendliness, Concentration and Startle. The scales were shown to be internally consistent. A comparison of these scales with the English mood scales was presented.

Adolescent↗

PubMed1992

Ultrastructural analysis of platelet-like particles from a human megakaryocytic leukemia cell line (CMK 11-5).

Ultrastructural observations were performed to further characterize the human megakaryocytic leukemia cell line, CMK, and its subclone, CMK11-5. We found that particles derived from CMK11-5 cells had cytoplasmic projections and no nucleus, and that some particles contained alpha granules. Incubation with ADP induced fibrinogen receptors on the surface of these particles. Furthermore, the particles had glycoprotein Ib antigen on their surfaces, and attached nonreversibly to rabbit aortic subendothelium, showing associated morphological changes similar to those observed in normal platelets. CMK and CMK11-5 are the first megakaryocytic cell lines that have been found to release particles that have some of the same functions as normal platelets. In particular, CMK11-5 seems to be a useful model for studying megakaryocyte function.

Blood Platelets↗

PubMed1992

Saposins: structure, function, distribution, and molecular genetics.

Saposins A, B, C, and D are small heat-stable glycoproteins derived from a common precursor protein, prosaposin. These mature saposins, as well as prosaposin, activate several lysosomal hydrolases involved in the metabolism of various sphingolipids. All four saposins are structurally similar to one another including placement of six cysteines, a glycosylation site, and conserved prolines in identical positions. In spite of the structural similarities, the specificity and mode of activation of sphingolipid hydrolases differs among individual saposins. Saposins appear to be lysosomal proteins, exerting their action upon lysosomal hydrolases. Prosaposin is a 70 kDa glycoprotein containing four domains, one for each saposin, placed in tandem. Prosaposin is proteolytically processed to saposins A, B, C and D, apparently within lysosomes. However, prosaposin also exists as an integral membrane protein not destined for lysosomal entry and exists uncleaved in many biological fluids such as seminal plasma, human milk, and cerebrospinal fluid, where it appears to have a different function. The physiological significance of saposins is underlined by their accumulation in tissues of lysosomal storage disease patients and the occurrence of sphingolipidosis due to mutations in the prosaposin gene. This review presents an overview of the occurrence, structure and function of these saposin proteins.

Animals↗

PubMed1991

Human placental sialidase complex: characterization of the 60 kDa protein that cross-reacts with anti-saposin antibodies.

Sialidase isolated from human placenta is associated with several proteins including acid beta-galactosidase, carboxypeptidase, N-acetyl-alpha-galactosaminidase, and others. These proteins are thought to form an aggregated complex during isolation of sialidase. One of the proteins of 60 kDa was recently identified by Potier et al. (Biochem. Biophys. Res. Comm. 173, 449-456, 1990) as a sialidase protein: this protein also cross-reacted with anti-prosaposin antibodies. We have isolated this protein and from the following evidence identified it as a heavy chain component of immunoglobulin G and not sialidase or a derivative of prosaposin. On gel filtration HPLC, sialidase activity and the 60 kDa protein were clearly separated from one another. The 60 kDa protein cross-reacted not only with antibodies raised against human saposins A, C, and D, but also with second antibody (goat anti-rabbit immunoglobulin G antibody) alone. This 60 kDa protein strongly cross-reacted with anti-human immunoglobulin G antibodies. The sequence of the initial 15 amino acids from the N-terminus of the 60 kDa protein was identical to the sequence of an immunoglobulin G heavy chain protein Tie (gamma 1).

Amino Acid Sequence↗

PubMed1991

Binding specificity of D-mannose 6-phosphate receptor of rabbit alveolar macrophages.

The existence of terminal D-mannosyl 6-phosphate groups (Man-6-P) was required (for an inhibitor) to exert a strong inhibitory potency against the binding of bovine serum albumin (BSA) conjugated with 17 molecules of penta-D-mannose 6-phosphate [(M5P)17-BSA] to the Man-6-P receptor in rabbit alveolar macrophages. In addition, the underlying oligosaccharide structures, such as linkage mode between the nonreducing sugar group and the penultimate sugar residue, and the length of sugar chain also affected the inhibitory potency in this system. In general, the oligosaccharides with an alpha-(1----2)-linked Man-6-P unit gave stronger inhibitory potencies than those with an alpha-(1----3)- or alpha-(1----6)-linked Man-6-P unit. Trisaccharides containing a terminal Man-6-P group were more potent inhibitors than disaccharides. A synthetic, branched, and divalent ligand, which does not have a penultimate sugar residue, gave about the same level of inhibitory potency as Man-6-P itself. The "cluster effect" was observed in this system, i.e., as the number of Man-6-P units conjugated to BSA [(Man-6-P)5,5,8, and 46-BSA] increased, the stronger inhibitory potencies were observed with decreasing I50 values of 1.93, 1.36, and 0.0345 microM, respectively. Synthetic divalent oligosaccharides also showed higher inhibitory potencies than the corresponding monovalent oligosaccharides.

Animals↗

PubMed1991

Saposin proteins: structure, function, and role in human lysosomal storage disorders.

Saposins are sphingolipid activator proteins, four of which are derived from a single precursor, prosaposin, by proteolytic processing. These small heat-stable glycoproteins (12-14 kDa) are required for the lysosomal hydrolysis of a variety of sphingolipids. Characterization of these four activator proteins, two of which were recently discovered, and their importance in human health and disease are reviewed in this article.

Amino Acid Sequence↗

PubMed1991

Intracellular recordings from rat thalamic VL neurons: a study combined with intracellular staining.

Intracellular recordings from thalamic neurons receiving cerebellar inputs were performed under urethane anesthesia in the rat. A total of 64 neurons were recorded intracellularly with micropipettes filled with 4% biocytin solution (dissolved in 0.5 M K-acetate), and cerebellar-induced EPSPs (CN-EPSPs), the membrane resistance and firing properties were analyzed with intracellular current injections. The mean latency of CN-EPSPs was 1.9 +/- 0.8 ms and the mean input resistance measured in 10 neurons was 17.6 +/- 5.0 M omega. Thirty-two out of 35 stained neurons were analysed morphologically; 28 of these neurons were located in the VL, and 26 received CN-EPSPs. Their somata were round or polygonal in shape and the mean size was 22.5 x 15.2 microns. They had radially extending spinous dendrites, and the mean radii of the dendritic fields were 214.7 microns in the frontal and 171.4 microns in the sagittal planes. These morphological features were similar to those observed in the sensory relay nucleus of the thalamus.

Animals↗

PubMed1991

Possible mechanism of the preventive effect of BCG against diabetes mellitus in NOD mouse. II. Suppression of pathogenesis by macrophage transfer from BCG-vaccinated mice.

Our previous reports showed that a single injection of live BCG, one of the biological response modifiers, prevents insulitis and overt diabetes in NOD mice and that the suppression could be due to the generation of some type of suppressor cells in the BCG-treated mice. Furthermore, a more recent study has revealed that macrophages suppressive against a variety of lymphocyte functions can be induced by BCG, which suggests that these macrophages are involved in the suppression of the pathogenesis. To obtain valid evidence for this speculation, the effects of transfer of macrophage and T-cell fractions on the pathogenesis were examined in the present study. Transfer of macrophage-enriched spleen cell fraction harvested from the BCG-treated females to young females abolished the occurrence of spontaneous diabetes up to the age of 25 to 30 weeks. Also, macrophage transfer prevented the progress of insulitis. In contrast, transfer of a T-cell-enriched fraction did not suppress insulitis and overt diabetes. From these results, it could be concluded that the suppression of the autoimmune pathogenesis of diabetes by BCG is due to the generation of suppressor macrophages.

Animals↗

PubMed1991

Catecholamines in experimentally growth-retarded rat fetus.

This study was designed to evaluate the sympathoadrenal system in rat IUGR fetuses prepared by the Wigglesworth method. Samples were obtained on day 20 of gestation. In the amniotic fluid, concentrations of norepinephrine (NE) and particularly epinephrine (E) were significantly higher in IUGR fetuses than in normally developed fetuses (NE: p less than 0.05, E: p less than 0.01). L-Dopa and three catecholamines in the adrenal glands were decreased in IUGR fetuses. The mol ratios (L-dopa: dopamine: NE: E) were 1: 4: 35: 63 in IUGR fetuses and 1: 5: 39: 87 in normal fetuses. The ratio for epinephrine to L-dopa was significantly lower in IUGR fetuses (p less than 0.05). Adrenal phenylethanolamine-N-methyltransferase activities showed no difference between the two groups. From these results, adrenal epinephrine synthesis in IUGR fetuses was thought to be normal. Because of the depletion of adrenal epinephrine in IUGR fetuses, the plasma epinephrine concentrations were significantly lower after acute hemorrhagic shock (p less than 0.01). However, the plasma concentrations of dopamine and norepinephrine were significantly higher (dopamine: p less than 0.01, NE: p less than 0.001) in IUGR fetuses. These findings suggest that the hypersecretion of adrenal epinephrine is a protective response to chronic stress and the decrease of adrenal epinephrine may be a causative factor for the reduced reserves in the defense mechanism of IUGR fetuses.

Adrenal Glands↗

PubMed1991

The production mechanism of amniotic fluid dopamine in rats.

The production of dopamine in amniotic fluid was studied using Wistar rats. The dopamine concentrations in the amniotic fluid increased significantly between each day of gestation from day 18 to day 21, and a marked increase was observed during the last two days. The concentrations of dopamine in the fetal plasma, however, did not change with the gestational age. There was a significant increase in the fetal plasma L-dopa, which is the precursor of dopamine, without any changes in maternal plasma L-dopa levels during late gestation. Dopa decarboxylase (DDC) activity was also measured in the fetal rat kidney from gestation day 17 to day 21. DDC activity, which was low on day 17, increased with advanced gestation. DDC activity on day 21 was 0.68 nmol/mg tissue/h, about 13-fold higher than on day 17. These results suggest that fetal plasma L-dopa may be converted to dopamine by fetal kidney DDC, and that the dopamine is voided into the amniotic cavity in fetal urine.

Amniotic Fluid↗