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Biomedical subjects

S Mizuno

Publications and source records attributed to S Mizuno.

At least 307 records · Page 17Linked to original sources
PubMed1993

Characterization of a 64-kd protein phosphorylated during chemotactic activation with IL-8 and fMLP of human polymorphonuclear leukocytes. II. Purification and amino acid analysis of phosphorylated 64-kd protein.

Lung giant cell carcinoma-derived chemotactic protein (LUCT)/IL-8 and fMet-Leu-Phe stimulate phosphorylation of a 64-kd protein (p64) in 32P-labeled human polymorphonuclear leukocytes (PMNs). The p64 was purified from cytosol of human PMNs (1.8 x 10(9) cells) by DEAE-Sepharose CL6B column chromatography, hydroxyapatite HPLC, and reverse-phase HPLC. By hydroxyapatite HPLC, p64s were separated and produced two peaks containing both nonphosphorylated and phosphorylated p64. Amino acid composition of each p64 was determined. Each p64 was directly subjected to amino acid sequencing, but the amino acid residue in the amino-terminal of the proteins could not be detected. From the results of amino acid composition and other characters of p64, it is suggested that p64 is identical to l-plastin, which is a leukocyte-specific protein.

Amino Acid Sequence↗
PubMed1993

Method for simultaneous detection of protein kinase A, protein kinase C, protein tyrosine kinase, and calmodulin-dependent protein kinase activities.

We report a simple method that permits simultaneous detection of multiple protein kinase activities using postnuclear supernatant of v-src transformed NIH3T3 cells. A supernatant is incubated with activators of protein kinases and [gamma-32P]ATP, and the phosphorylated proteins are analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The method enables detection of activities of at least four protein kinases (protein kinase A, protein kinase C, protein tyrosine kinase(s), and calmodulin-dependent protein kinase III) on a single gel. Experiments using various specific activators and inhibitors of protein kinases indicated that this method can, in crude preparations, reliably detect the protein kinase activities intended for measurement. Protein kinase C activity disappeared when membranes were solubilized, demonstrating the importance of membrane environment for its function. This method should be particularly useful for evaluating and screening protein kinase inhibitors.

3T3 Cells↗
PubMed1993

Down-regulation of the surface expression of class I MHC antigens by human cytomegalovirus.

Class I major histocompatibility complex (MHC) antigens of higher eukaryotes play a crucial role in the recognition of human cytomegalovirus (HCMV)-infected cells by cytotoxic T lymphocytes. In the present study, we have demonstrated that HCMV infection resulted in a marked reduction in the surface expression of class I MHC antigens on human embryonic lung fibroblasts (HEL). Even when HCMV-infected HEL were cultured in the presence of 9-(1,3-dihydroxy-2-propoxymethyl)-guanine (DHPG), the reduction was observed to the same extent, indicating that HCMV DNA synthesis was not required for this phenomenon. However, immunoprecipitation studies have shown that there was no significant reduction in the synthesis of either the heavy chain or the light chain of class I MHC antigens after HCMV infection. In addition, Western blotting studies have revealed that the total amount of the antigens was almost unaltered after HCMV infection. These results suggest that the reduction in the cell surface expression of class I MHC antigens is due to some defect occurring post-translationally, most likely at the level of the correct complex formation and/or the intracellular transport of class I MHC antigens.

Blotting, Western↗
PubMed1993

Germ line-restricted, highly repeated DNA sequences and their chromosomal localization in a Japanese hagfish (Eptatretus okinoseanus).

The various species of Japanese hagfish, namely, Eptatretus okinoseanus (types A and B), Eptatretus burgeri and Myxine garmani, are known to eliminate a fraction of their chromosomes during early embryogenesis. High molecular weight DNA from germ line cells and somatic cells of these hagfish species was isolated and digested with different restriction enzymes. The DNA fragments were separated by agarose gel electrophoresis. Digestion with BamHI and DraI generated two weak bands and one weak band, respectively, that were estimated to be about 90, and 180 bp and about 90 bp long and were limited to the germ line DNA in both types of E. okinoseanus. DNA filter hybridization experiments showed that the two BamHI fragments and the one DraI fragment were present almost exclusively in the germ line DNA of E. okinoseanus. Thus, these DNA fragments appear to be eliminated during embryogenesis. Moreover, evidence was obtained that these fragments are highly and tandemly repeated. Molecular cloning and sequence analysis revealed that the BamHI fragments are mainly composed of a family of closely related sequences that are 95 bp long (EEEo1, for Eliminated Element of E. okinoseanus 1), and the DraI fragment is composed of another family of closely related sequences that are 85 bp long (EEEo2). The two DNA families account for about 19% of the total eliminated DNA in E. okinoseanus type A. Fluorescence in situ hybridization experiments demonstrated that the two families of DNA are located on several C-band-positive, small chromosomes that are limited to germ cells in both types of E. okinoseanus.

Animals↗
PubMed1993

Identification and localization of two genes on the chicken Z chromosome: implication of evolutionary conservation of the Z chromosome among avian species.

A cDNA clone containing an insert of about 3.4 kb, pCIREBP, was isolated from the chicken liver cDNA library and identified as a clone for the chicken homologue of iron-responsive element-binding protein (IREBP). The deduced amino acid sequence showed 88% identity with that of the mouse IREBP and 17 out of the 20 active site residues of the pig heart mitochondrial aconitase were conserved. Another cDNA clone, pZOV3, containing an insert of about 4.5 kb was isolated from the chicken ovary cDNA library. This cDNA contained an open reading frame for 327 amino acid residues, whose sequence had partial similarity to two immunoglobulin superfamily proteins; mouse GP-70 and chicken HT7. Fluorescence in situ hybridization using corresponding genomic clones revealed that both genes are localized on the Z chromosome; the ZOV3 gene at the middle of the short arm and the IREBP gene at the boundary of heterochromatin on the long arm. Southern blot hybridization to male and female genomic DNA preparations from six species representing five avian genera suggested that these two genes are Z-linked in all the species tested.

Amino Acid Sequence↗
PubMed1993

Stabilization of biliary lipid particles by ursodeoxycholic acid. Prolonged nucleation time in human gallbladder bile.

We evaluated the effect of ursodeoxycholic acid on the metastability of human bile as reflected by nucleation time and also assessed the mechanism of its action in an ultrastructural study. Ursodeoxycholic acid significantly prolonged the nucleation time of gallbladder bile from cholesterol gallstone patients without causing either drastic changes in the distribution of cholesterol between the nonmicellar and micellar fractions of bile or biliary cholesterol desaturation. Gel permeation chromatography resolved two distinct components of the nonmicellar fraction: vesicles and phospholipid lamellae (identified by electron microscopy). Nonmicellar cholesterol was predominantly carried by vesicles in the bile of untreated gallstone patients, whereas it was chiefly carried by phospholipid lamellae in patients treated with ursodeoxycholic acid. Furthermore, phospholipid lamellae from untreated gallstone patients showed rapid transformation and cholesterol microcrystal formation within seven days, whereas the lamellae from ursodeoxycholic acid-treated patients were stabilized and showed little change. On the other hand, biliary mucin concentration was reduced by the treatment with ursodeoxycholic acid. These findings suggest that ursodeoxycholic acid stabilizes phospholipid lamellae and consequently prolongs nucleation time. It is also possible that the reduction of biliary mucin plays a role in this process.

Adult↗
PubMed1993

W-heterochromatin of chicken; its unusual DNA components, late replication, and chromatin structure.

About 65% of DNA in the chicken W chromosome has been shown to consist of XhoI and EcoRI family repetitive sequences. These sequences showed remarkable delay in the electrophoretic mobility at low temperature on a polyacrylamide gel. Three dimensional structures of the 0.7-kb XhoI and the 1.2-kb EcoRI family repeating units were estimated to be irregular solenoids using a computer program based on wedge angles of all the 16 dinucleotide steps. Fluorescence in situ hybridization demonstrated that these two family sequences were localized in a major heterochromatic body in an interphase nucleus. Incorporation of bromodeoxyuridine into the W chromosome in the synchronous culture of MSB-1 cells occurred about 1 h later than the peak of S phase. The chromatin structure formed along XhoI and EcoRI family sequences was suggested to be different from the total chromatin or chromatin containing the beta-actin gene sequence in that the linker DNA lengths of the former were significantly longer. Fractionation of the HaeIII-digested MSB-1 nuclei yielded a chromatin fraction in which XhoI family sequences were partially enriched. Several DNA-binding proteins showing higher affinity for the XhoI family sequence were present in this fraction.

Actins↗
PubMed1993

Activation of GABAA receptors in hypothalamus modulates PGF2 alpha- or PGE2-induced catecholamine secretion in rats.

We previously reported that injection of PGF2 alpha into the third cerebral ventricle produces hyperglycemia and hyperthermia associated with catecholamine secretion in anesthetized rats. We have also studied the potency of catecholamine secretion induced by injecting PGE2 or PGF2 alpha into the third cerebral ventricle and the effect of the GABA-selective agonist, muscimol, on the catecholamine secretion induced by PGE2 or PGF2 alpha. Administration of 50 micrograms of PGE2 into the third cerebral ventricle increased norepinephrine secretion to a greater extent than the same dose of PGF2 alpha, whereas the latter increased epinephrine secretion to a greater degree. These effects paralleled the potencies of the hyperglycemic and hyperthermic effects of PGF2 alpha and PGE2, respectively. Simultaneous injection of 2.5 nmol of muscimol into the third cerebral ventricle with 50 micrograms of PGF2 alpha or PGE2 completely suppressed epinephrine and norepinephrine secretion induced by PGF2 alpha or PGE2. These findings suggest that central PGF2 alpha and PGE2 stimulate epinephrine and norepinephrine secretion with different potencies, and that brain GABAA receptors suppress catecholamine secretion induced by PGF2 alpha or PGE2.

Animals↗
PubMed1993

Isolation and amino acid sequence of a chemotactic protein, LECT/interleukin 8, from a human myeloid leukemia cell line, ML-1.

We looked for chemotaxin/interleukin 8 (CT/IL-8) activity in the culture fluids of 97 human leukemia cell lines and found it in two of the T cell lines, six of the myeloid cell lines, and one of the normal B-cell lines. It was particularly strong in the culture fluids of two cell lines. These cell lines secreted a chemotactic protein into the culture fluids under certain conditions of stimulation with phorbol-12-myristate 13-acetate (PMA), lipopolysaccharide, or hemagglutinin-P. A myeloid leukemia cell line, ML-1, secreted an inducible chemotaxin when stimulated with PMA (1 ng/ml) for 24 h. We purified the chemotaxin from ML-1 cell culture fluid using an improved procedure: concentration with DEAE-Sepharose CL-6B and CM-Sepharose CL-6B, CM-Sepharose column chromatography, and reverse-phase 5TMS-300 column on HPLC with the retention time coinciding with that of LUCT/IL-8 [Suzuki et al., 1989, J. Exp. Med. 169, 1895]. The yield was 200 micrograms protein from 6 liters of the culture fluid. The N terminus of CT/IL-8 was AVLPR-SAKELRXQXIKTYSK- - -, the same as that of LUCT/IL-8, which is constitutively secreted from lung giant cell carcinoma LU65C cells. The optimal concentration in the chemotactic activity of CT/IL-8, equivalent to that of bacterial chemotactic peptide fMet-Leu-Phe (10 nM), was found to be 5 nM. The results show that this chemotaxin is identical to LUCT/IL-8.

Amino Acid Sequence↗
PubMed1993

Filtration through a polyester white cell-reduction filter of plasma-poor platelet concentrates prepared with an acetate-containing additive solution.

It is of practical importance to known whether the adsorption of platelets and contaminating white cells (WBCs) by the WBC-reduction filter is altered when platelet concentrates (PCs) are prepared in a plasma-poor condition with an acetate-containing additive solution (Seto sol). Plasma-poor PCs with 11-percent residual plasma were prepared from apheresis platelet-rich plasma by using a sterile docking device with steam-sterilized Seto sol. Seto sol contains 115 mM (115 mmol/L) NaCl, 4 mM (4 mmol/L) KCl, 3 mM (3 mmol/L) MgCl2, 10 mM (10 mmol/L) Na3PO4, 15 mM (15 mmol/L) acetate, 3 mM (3 mmol/L) Na3 citrate, and 10 mM (10 mmol/L) glucose (pH 7.1). The solution was steam-sterilized under nitrogen gas. On Days 1 and 5, pooled Seto sol PCs (2.4 x 10(11) platelets) were filtered with a polyester filter at a flow rate of 10 mL per minute. The WBC-removal rate was over 99.9 percent with a platelet recovery of 88 percent following Day 1 filtration. These values were very similar to those of plasma PCs, and 84-percent recovery was achieved following Day 5 filtration. However, when 1 unit of Seto sol PCs with half the number of platelets was filtered with the polyester filter, platelet recovery was about 16 to 17 percent less than that of plasma PCs. Platelet quality was maintained if pooled Seto sol PCs were filtered on Day 1 and stored for over 4 days. Filtration did not alter platelet function in 1-day-old or 5-day-old Seto sol PCs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adsorption↗
PubMed1993

Immunological identification of the major disulfide-linked light component of silk fibroin.

The light protein components of silk fibroin were analyzed by Western blotting using polyclonal antibodies against two synthetic peptides that are segment of the light (L-) chain [Yamaguchi et al. (1989) J. Mol. Biol. 210, 127-139] and P25 [Chevillard et al. (1986) Sericologia 26, 435-449], respectively, and against the whole L-chain. Both the L-chain and P25 were present with fibroin in the lumen of the posterior silk gland and in the cocoon. The L-chain was identified as the major light component that was disulfide-linked to the fibroin heavy (H-) chain, whereas P25 was a minor component whose association with the H-chain was suggested to be non-covalent.

Amino Acid Sequence↗
PubMed1993

Characterization of dog interleukin-2 activity.

Proliferative activity of murine interleukin-2 (IL-2) dependent T cells (CTLL-2) was detected in the culture supernatant of canine peripheral blood lymphocytes (PBL) stimulated with phytohemagglutinin-P (PHA-P), and was defined as dog IL-2. The highest production of IL-2 was obtained under the conditions in which a PBL population of 2 x 10(6) cells/ml was stimulated with PHA-P at a concentration of 10 micrograms/ml at 38 degrees C for 48 hr. Dog IL-2 activity was significantly inhibited by heating at 65 degrees C, acidification under pH 4, alkalification over pH 10, and trypsin exposure. A peak of dog IL-2 activity was detected in the fraction with a molecular weight of approximately 31,000 by gel filtration. Long-term culture of canine lymphocytes was successful over 10 passages by using dog IL-2 with PHA-P-stimulation every 3 passages. The cultured cells mostly consisted of small- and medium-sized lymphocytes. These cells reacted to anti-dog thymocyte rabbit serum and anti-dog Thy-1 mouse monoclonal antibody. These cells were therefore considered to originate in T-lineage lymphocytes. Cytostasis of PBL from intact dogs reacting to canine transmissible venereal sarcoma cells was increased significantly when PBL was cultured for more than 30 days with homologous IL-2.

Animals↗
PubMed1993

Acute obstructive hydrocephalus caused by a migrating intraventricular calculus. Case report.

A 10-year-old boy presented with acute obstructive hydrocephalus caused by the impaction of a calculus on the cerebral aqueduct. The calculus migrated from the third ventricle to the fourth ventricle after ventricular drainage and right ventriculoperitoneal shunt placement had been performed. The nature and origin of the calculus could not be determined, although its release from the choroid plexus in the lateral ventricle is highly possible.

Acute Disease↗
PubMed1993

T lymphoid/myeloid bilineal crisis in chronic myelogenous leukemia.

We describe 2 cases of "bilineal" crisis in chronic myelogenous leukemia (CML) with T cell and myeloid phenotypes. In both cases, morphocytochemically distinct myeloid and T lymphoid blast populations proliferated simultaneously in the phase of blastic crisis--myeloperoxidase (MPO)-positive, CD7+/CD33+ myeloblasts in the peripheral blood, and MPO-negative, periodic acid Schiff (PAS)-positive lymphoblasts in the lymph nodes. In each case, common karyotypes containing Ph1 translocation were demonstrated in both the peripheral blood and the lymph node samples. In Case 1, the lymph nodes were occupied by > 90% lymphoblasts, which were positive for CD2, cytoplasmic CD3 (cCD3), CD5 and CD7 and terminal deoxynucleotidyl transferase (TdT), but negative for myeloid antigens. Myeloblasts and T lymphoblasts showed an identical rearrangement of the bcr gene by Southern blotting analysis, although the clonal rearrangement of the T cell receptor (TcR)-delta gene was seen only in T lymphoblasts. In Case 2, simultaneous proliferation of myeloblasts and lymphoblasts was documented morphocytochemically in the lymph node, and a flow cytometric analysis revealed the coexistence of CD7+/CD33+ and CD7+/CD33- blast populations. Each blast population was enriched by antibody-conjugated immunomagnetic beads; the former was positive for MPO by 64% but negative for cCD3 and TdT, whereas the latter was positive for cCD3 and TdT but negative for MPO (< 1%). CD7+/CD33+ myeloblasts and CD7+/CD33- lymphoblasts showed an identical rearrangement of the bcr gene. Neither TcR-beta, TcR-gamma nor the TcR-delta gene was clonally rearranged in either population. These observations clearly indicate that T lymphoid and myeloid blasts share common Ph1-positive progenitors, and that Ph1-positive T lymphoid/myeloid progenitors are probably involved in the development of blastic transformation in some percentage of CML patients.

Adult↗
PubMed1993

[Regional phacomatosis with cerebral AVMs and cavernous hemangioma of the skull--report of a case].

We report the coexistence of multiple arteriovenous malformations (AVMs) and hemangioma of the skull in a 38-year-old man with associated varicose veins in his scalp. The patient also had hypotrophy of all right limb tissues with skin pigmentation and syndactyly of both feet. CT scans revealed intraventricular hemorrhage and a hemangioma of the skull at the posterior fossa. Because of the location of the arteriovenous malformations, surgical evacuation and resection were not attempted. The hemangioma was totally removed to decompress the posterior fossa. A few cases of regional phacomatosis with intracranial AVMs have been reported, but we could not find a report of the coexistence of intracranial multiple AVMs and hemangioma of the skull with associated varicose veins of the scalp and skeletal hypotrophy. We discuss on the etiology of the coexistence of regional phacomatosis and hemangioma and on the difference between our case and typical regional phacomatosis.

Adult↗