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Biomedical subjects

Y Kishimoto

Publications and source records attributed to Y Kishimoto.

At least 199 records · Page 11Linked to original sources
PubMed1990

[A study on changes of liver and salivary glands in rats with experimentally induced liver injuries. Pathological and biochemical observations].

Changes in the salivary glands, liver and pancreas in rats with experimentally induced liver injuries were examined. The injuries (experimental group) were induced by subcutaneous injections of carbon tetrachloride (0.01ml/kg body weight) in a 50% olive-oil solution. The injections were administered twice weekly for 10,20 and 40 weeks. Control animals received the same doses of olive oil during the same periods. 1. In the experimental group, serum glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) increased remarkably, whereas serum albumin decreased. 2. Swelling of the liver and multiple nodular formations occurred in the experimental group. Liver fibrosis with the formation of pseudolobules indicated a form of liver cirrhosis. 3. No significant histological changes were observed in the pancreases of animals in the 10- and 20-week experimental groups. Vacuolation in the acinar cells was observable in 3 of 8 cases in the 40-week experimental group. 4. In connection with histological findings of parotid glands, vacuolation of the acinar cells occurred in 7 of 12 cases in the 10-week experimental group, in 7 of 8 cases in the 20-week experimental group, and in all 8 cases in the 40-week experimental group. Vacuole numbers and sizes increased as the experimental period was prolonged. 5. Immunohistochemical investigation showed strong positive reactions to the anti-amylase antibody around vacuoles in acinar cells of parotid glands. In unvacuolated acinar cells, on the other hand, only slight positive reaction was observed. 6. Electronmicroscopic observation of the acini revealed greatly enlarged lumina and dilated intercellular canaliculi connected to the lumina. Small vacuoles were observed on the basement of the acini. 7. No such significant changes as fibrosis, vacuolation, and atrophy of acinar cells were observed in the submandibular and sublingual glands of the experimental animals. 8. Serum amylase activity increased more in the experimental than in the control rats. Electrophoretic patterns suggested that in the control group 95 percent of serum amylase was parotid type, and also in the experimental group 95 percent of serum amylase was parotid type. 9. Amylase activity in the parotid glands also increased more in the experimental than in the control animals.

Alanine Transaminase↗
PubMed1989

Temperature effect on endocytosis and exocytosis by rabbit alveolar macrophages.

Endocytosis of 125I-mannose-bovine serum albumin (BSA) and exocytosis of 125I-mannose-poly-D-lysine by rabbit alveolar macrophages were examined as a function of temperature. A plot for total ligand uptake (cell-associated ligand plus degraded ligand) versus time shows a single inflection point at 20 degrees C. Ligand degradation does not occur below 20 degrees C. Internalization of surface-bound 125I-mannose-BSA is negligible below 10 degrees C. The rate constant for internalization increases dramatically above 20 degrees C: 0.02 min-1 at 20 degrees C, 0.05 min-1 at 25 degrees C, 0.13 min-1 at 30 degrees C, and 0.29 min-1 at 35 degrees C. 125I-Mannose-N-acetyl-poly-D-lysine preloaded in lysosomes is exocytosed in a temperature and time-dependent fashion. Even at lower temperatures (2-10 degrees C), secretion of 125I-mannose-N-acetyl-poly-D-lysine was detected, indicating that movement of lysosomal content to plasma membrane and beyond cannot be suppressed at these temperatures. Thus, the temperature dependence of exocytosis of an 125I-labeled ligand is quite different from that of endocytosis, suggesting that the two processes are controlled by different mechanisms. Stimulation of secretion of preloaded 125I-mannose-N-acetyl-poly-D-lysine by mannose-BSA was more pronounced at lower temperatures with a sharp inflection point at 10 degrees C. These findings suggest that endosomes containing newly internalized mannose-BSA interact with the exocytosis pathway and enhance secretion of 125I-mannose-N-acetyl-poly-D-lysine from lysosomes.

Animals↗
PubMed1989

Characterization of novel glycolipids from the giant cockroach (Blaberus colosseus).

A novel class of glycolipids, assigned the trivial name blaberosides, was isolated from whole head tissues of the giant cockroach (Blaberus colosseus). The class consists of two closely related families, blaberoside I and blaberoside II, each containing species differing by 26 atomic mass units. The structure of these gentiobiose-based glycoglycerolipids was elucidated by chromatographic behavior, nuclear magnetic resonance spectroscopy, mass spectrometry, and analysis of chemical degradation products and derivatives. Species in the blaberoside I family have been identified as 2-O-[6'-O-(6"-O-3-hydroxy-11-eicosenoyl-beta-D-glucopyranosyl)-bet a-D- glucopyranosyl]-3-(hexadecyloxy)-1-(3-hydroxy-11-eicosenoyl)-1,2-p ropanediol (blaberoside Ia) and 2-O-[6'-O-(6"-O-3-hydroxy-11-eicosenoyl-beta-D-glucopyranosyl)-bet a- D-glucopyranosyl]-3-(6-octadeceloxy)-1-(3-hydroxy-11-eicosenoyl )-1,2- propanediol (blaberoside Ib). Two smaller homologs of the blaberoside II family were discerned to be 2-O-[6'-O-(6"-O-3-hydroxy-11- eicosenoyl-beta-D-glucopyranosyl)-beta-D-glucopyranosyl]-3-(hex ade cyloxy)- 1,2-propanediol (blaberoside IIa), and 2-O-[6'-O-(6"-O-3-hydroxy-11-eicosenoyl-beta-D- glucopyranosyl)-beta-D-glucopyranosyl]-3-(4-octadeceloxy)-1,2-prop anediol (blaberoside IIb). These compounds are unique because they are animal origin glyceroglycolipids with a highly flexible gentiobiose backbone, and a beta-linkage of the carbohydrate to the glycerol ether at the 2 position rather than the usual 1 position.

Animals↗
PubMed1989

Desorption of ions from rat membranes: selectivity of different ionization techniques.

Complex lipid biomarkers, including phosphatidylcholines, cerebrosides and sulfatides, are shown to be desorbed intact from rat brain myelin and rat liver microsomes by liquid secondary ion mass spectrometry, by plasma desorption and by laser desorption. Different polar lipids are favored by the different desorption techniques and as negative or positive ions. These selectivities support current theories about ionization for the different techniques.

Animals↗
PubMed1989

Electrophoretic characterization and immunoblot analysis of the proteins from the myelin-like light membrane fraction of shrimp ventral nerve (Penaeus duorarum).

1. The proteins of the light membrane fraction (LMF) from the ventral nerve of the pink shrimp (Penaeus duorarum) were separated by SDS gel electrophoresis and analysed by staining and immunoblotting. 2. Shrimp LMF carried four major proteins with apparent molecular weights of Mr = 21,500, 40,000, 78,000, 85,000 and four minor components (Mr = 36,000, 41,500, 43,000, 50,000). 3. None of these proteins bound Concanavalin A. 4. The four major proteins showed no reaction with antisera against six vertebrate myelin proteins. Only the minor Mr = 50,000 component was weakly recognized by the antibodies against mammalian myelin P0 protein.

Animals↗
PubMed1989

Saposin A: second cerebrosidase activator protein.

Saposin A, a heat-stable 16-kDa glycoprotein, was isolated from Gaucher disease spleen and purified to homogeneity. Chemical sequencing from its amino terminus and of peptides obtained by digestion with protease from Staphylococcus aureus strain V-8 demonstrated that saposin A is derived from proteolytic processing of domain 1 of its precursor protein, prosaposin. Processing of prosaposin (70 kDa) also generates three other previously reported saposin proteins, B, C, and D, from its second, third, and fourth domains. Similar to saposin C, saposin A stimulates the hydrolysis of 4-methylumbelliferyl beta-glucoside and glucocerebroside by beta-glucosylceramidase and of galactocerebroside by beta-galactosylceramidase, mainly by increasing the maximal velocity of both reactions. Saposin A is as active as saposin C in these reactions. Saposin A has no significant effect on other sphingolipid and 4-methylumbelliferyl glycoside hydrolases tested. Saposin A has two potential glycosylation sites that appear to be glycosylated. After deglycosylation, saposin A had a subunit molecular mass of 10 kDa and was as active as native saposin A. However, reduction and alkylation abolished the activation. A three-dimensional model comparing saposins A and C reveals significant sequence homology between them, especially preservation of conserved acidic and basic residues in their middle regions. Each appears to possess a conformationally rigid hydrophobic pocket stabilized by three internal disulfide bridges, with amphipathic helical regions interrupted by helix breakers.

Amino Acid Sequence↗
PubMed1989

Establishment of a human leukaemic cell line (CMK) with megakaryocytic characteristics from a Down's syndrome patient with acute megakaryoblastic leukaemia.

A new megakaryoblastic cell line (CMK), which also exhibits erythroid and myeloid markers, was established from a Down's syndrome patient suffering from acute megakaryoblastic leukaemia. The CMK cells were found to be positive in reactions with anti-platelet antibodies (anti-glycoproteins IIb/IIIa and Ib, and Plt-1). Platelet peroxidase (PPO) reactivity was found to be associated with the nuclear envelope and the endoplasmic reticulum but not with the Golgi apparatus. Some cells possessed cytoplasmic granules with the characteristics of alpha-granules and demarcation membranes. Karyotyping revealed near-tetraploidy (modal chromosome number of 95; ranging 87-98) and a translocation der(17)t(11;17), also found in the original leukaemic cells, confirming that the cells were derived from the patient's malignant blasts. The CMK cells were also found to be positive in reaction with anti-glycophorin A antibody, as well as with anti-myeloid antibodies (MY4, MY7 and MY9). Treatment of CMK cells with phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) greatly enhanced the reactivity with anti-platelet antibodies, increased the number of cells in which cytoplasm was dissociated into numerous segments and suppressed the reactivity with anti-glycophorin A. The proliferation of CMK cells was stimulated by interleukin-3 (IL-3) and granulocyte-macrophage colony stimulation factor (GM-CSF). This cell line should be a useful tool for analysing the basis of the afferent association between megakaryoblastic leukaemia and Down's syndrome, as well as for further study of megakaryocytic differentiation.

Bone Marrow↗
PubMed1989

Metabolism of amniotic fluid dopamine by fetal membranes.

The concentrations of L-dopa, three catecholamines and 3,4-dihydroxyphenylacetic acid (DOPAC) were measured both in the amniotic fluid and the fetal urine obtained at term elective cesarean section, using high performance liquid chromatography with electrochemical detection. Dopamine was the major compound in the fetal urine, while DOPAC predominated in the amniotic fluid. Monoamine oxidase (MAO) activity was detected in the fetal membranes by the method of Wurthman and Axelrod. MAO activities in the amnion, chorion and decidua were 0.023 +/- 0.003, 0.180 +/- 0.05 and 2.69 +/- 0.66 nmol/mg protein/min (mean +/- SE), respectively. Incubation experiments, using fetal membranes with human amniotic fluid, demonstrated that dopamine in amniotic fluid was metabolized to DOPAC by fetal membranes. Additional incubation experiments with pargyline, a MAO inhibitor, showed that it strongly inhibited the conversion of dopamine into DOPAC. These results suggest that the dopamine in amniotic fluid was metabolized to DOPAC by MAO in the fetal membranes. This mechanism may regulate the dopamine concentration in amniotic fluid.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1989

Characterization and regional distribution of individual gangliosides in goldfish central nervous system.

Gangliosides were partially purified from goldfish brain and fractionated by DEAE Fractogel column chromatography. Each fraction was then analyzed by HPTLC and also by HPLC after conversion of the gangliosides to 2,4-dinitrophenylhydrazides. The tetrasialoganglioside GQ1c was found to constitute more than 50% of the total gangliosides. Gangliosides in smaller quantities were also tentatively identified. These included GT1b, GT1c, GT2, GT3, GD1a, and several others. By using this information, the amounts of individual gangliosides in various regions of goldfish central nervous system were compared. Although all areas of brain examined contained similar concentrations of gangliosides, with GQ1c as the predominant component, retina and optic nerve contained significantly lower concentrations of GQ1c, and GM3 was the major component.

Animals↗
PubMed1989

Ultrastructural analysis of megakaryoblasts by simultaneous detection of platelet peroxidase and platelet glycoproteins.

We studied the phenotype of megakaryoblasts (MKB) in two patients with blastic crisis of chronic myeloid leukemia by simultaneous detection of platelet peroxidase (PPO) activity and platelet glycoproteins (GP) with monoclonal antibodies at the ultrastructural level. When 227A (anti-GPIb) was used, the finding of GP correlated well with the presence of PPO in the majority of MKB, and a few MKB were found to express PPO but lack GP. When 224B (anti-GPIIb/IIIa) was applied, we found a few MKB of a further type, which expressed GP but lacked PPO. These results indicate that the expression of platelet markers is partially aberrant in neoplastic MKB, and that MKB are heterogenous in their phenotypic expressions. Thus, the detection of PPO or GP alone may miss some MKB. For the accurate identification of MKB and the demonstration of aberrant expression of platelet markers, simultaneous detection of the markers seems to useful.

Blast Crisis↗
PubMed1988

Saposin D: a sphingomyelinase activator.

Saposin D, a newly discovered heat-stable, 10 kDa glycoprotein, was isolated from Gaucher spleen and purified to homogeneity. Chemical sequencing from its amino terminus demonstrated colinearity between its amino acid sequence and the deduced amino acid sequence of the fourth domain of prosaposin, the precursor of saposin proteins. Saposin D specifically stimulates acid sphingomyelinase but has no significant effect on the other hydrolases tested.

Enzyme Activation↗
PubMed1988

Anti-galactocerebroside antibodies in human cerebrospinal fluids determined by enzyme-linked immunosorbent assay (ELISA).

The standard ELISA technique was improved for the detection of antigalactocerebroside antibody in biological fluid. Mouse monoclonal antigalactocerebroside antibody was used to demonstrate specificity and sensitivity of the technique. After optimization of the assay, the usefulness of this measurement for the evaluation of patients with multiple sclerosis was assessed. The presence of antigalactocerebroside antibodies in the cerebrospinal fluid of 20 patients with multiple sclerosis, 10 with other neurological diseases and 10 normal individuals was determined. All the CSF samples from normal individuals were negative. In patients with multiple sclerosis 14 of the 20 samples had elevated levels of antigalactocerebroside antibody, whereas with other neurological diseases 5 out of 10 were positive. Antigalactocerebroside levels were lower in samples from patients during an acute relapse than in those from more chronic cases. These results indicate that the presence of antigalactocerebroside antibody in cerebrospinal fluid is not specific to MS but may reflect previous damage to myelin.

Antibodies, Monoclonal↗
PubMed1988

2,4-Dinitrophenylhydrazides of polysialogangliosides.

Treatment with 2,4-dinitrophenylhydrazine HCl in the presence of dicyclohexylcarbodiimide, converts gangliosides to their dinitrophenylhydrazides. This derivatization is the basis of a useful method for HPLC determination of gangliosides (K. Miyazaki, N. Okamura, Y. Kishimoto and Y. C. Lee (1986) Biochem. J. 235, 755-761). This procedure, however, yields two different GT1b products. By characterizing these two products using plasma desorption mass spectrometry, proton magnetic resonance and other chemical and physical techniques, we found that either one or two of the three sialic acid carboxyl groups in GT1b, were converted to dinitrophenylhydrazides. The remaining underivatized carboxyl groups formed lactones with hydroxyl groups from other carbohydrate residues. Also, while sialic acid residues of GD1a were fully derivatized, only one sialic acid in GD1b, two sialic acids in GT1a and two in GQ1b were converted to dinitrophenylhydrazides, the remaining carboxyl groups probably forming lactones. Sialic acid residues between galactose of the gangliotetraose chain and another sialic acid in polysialogangliosides appear to be underivatized possibly because of steric hindrance.

Chemical Phenomena↗
PubMed1987

Characterization and comparison of lipids in different squid nervous tissues.

We have studied the lipid composition of brain (optic and cerebral lobes), stellate ganglia and fin nerves of the squid. Cholesterol, phosphatidylethanolamine and phosphatidylcholine were the major lipids in these nervous tissues. Phosphatidylethanolamine contained about 3% of its amount in [corrected] plasmalogen form. Phosphatidylserine and -inositol, sphingomyelin and ceramide 2-aminoethylphosphonate were also present in significant amounts. In addition, cardiolipin and free fatty acids were detected in brain (each 2-3% of total lipids) and stellate ganglia (about 1% each), but not in fin nerves. Phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol from brain contained large amounts of polyunsaturated fatty acids, namely 20:4, 20:5 and 22:6 in the n-3 family. On the other hand, phosphatidylcholine, cardiolipin, and sphingomyelin, and ceramide 2-aminoethylphosphonate contained only saturated or monounsaturated C16-C18 fatty acids. The aldehyde moieties of ethanolamine plasmalogen were also C16-C18 saturated or monounsaturated. These lipid compositions are compared with those in other invertebrate nervous systems.

Animals↗
PubMed1987

Lipid metabolism in various regions of squid giant nerve fiber.

The purpose of this investigation was to compare the incorporation of radioactivity from various precursors into lipids of different regions of squid giant nerve fiber systems including axoplasm, axon sheath, giant fiber lobes which contain stellate ganglion cell bodies, and the remaining ganglion including giant synapses. To identify the labeled lipids, stellate ganglia including giant fiber lobes and the remaining tissue were first incubated separately with [14C]glucose, [32P]phosphate, [14C]serine, [14C]acetate and [3H]myristate. The radioactivity from glucose, after conversion to glycerol and fatty acids, was incorporated into most lipids, including triacylglycerol, free fatty acids, cardiolipin, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, phosphatidylserine, sphingomyelin and ceramide 2-aminoethylphosphanate [corrected]. The radioactivity from serine was largely incorporated into phosphatidylserine and, to a lesser extent, into other phospholipids, mainly as the base component. The sphingoid bases of ceramide and sphingomyelin were also significantly labeled. Saturated and monounsaturated and, to a lesser extent, polyunsaturated fatty acids of these lipids were synthesized from acetate, glucose and myristate. Among the major lipids, cholesterol was not labeled by any of the radioactive compounds used. Ganglion residues incorporated the most radioactivity in total lipids from either [14C]glucose or [14C]serine, followed by giant fiber lobes and then sheath. Axoplasm incorporated the least. Among various lipids, phosphatidylethanolamine with shorter saturated fatty acids and phosphatidylglycerol contained the most radioactivity from glucose in all regions. Axoplasm was characterized by a higher proportion of glucose radioactivity in ceramide, sphingomyelin and phosphatidylglycerol. Axoplasm and sheath contained a higher proportion of serine radioactivity than did the other two regions in ceramide. Essentially no radioactivity from [14C]galactose was incorporated in any region.

Acetates↗