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Biomedical subjects

Y Hamaguchi

Publications and source records attributed to Y Hamaguchi.

At least 127 records · Page 7Linked to original sources
PubMed1986

Glycoprotein analysis of middle ear effusions by rectin-conjugated sepharose affinity chromatography.

We analyzed the composition of glycoproteins in serous and mucoid middle ear effusions (MEE) collected from patients with chronic otitis media with effusion (OME), and compared this with plasma glycoproteins, using rectin-conjugated sepharose. The concentration ratio of rectin-absorbed glycoproteins to total protein concentration in serous MEE resembled that in plasma, although mucoid MEE had a higher concentration ratio than that of the serous effusions. By SDS-polyacrylamide gel electrophoresis analysis, the molecular weight pattern of glycoproteins adsorbed to wheat germ agglutinin (WGA) gel in serous MEE was more similar to that in plasma than in the mucoid effusions. Using 2-mercaptoethanol, the basic low-molecular-weight components of the glycoproteins were almost identical in MEE and in plasma. Our findings show that mucoid MEE has a greater amount of plasma and epithelial glycoproteins than does serous fluid. The composition of these latter substances is more similar to that of plasma glycoproteins. The strong disulfide bonds present in glycoproteins may significantly contribute to the physicochemical properties of mucoid MEE.

Adult↗
PubMed1986

Lipid deposition in the aorta of adjuvant arthritic rats with hypercholesterolemia.

This study offers findings which should aid in the development of a convenient animal model of atherosclerosis. Inbred Fisher strain rats were fed an atherogenic diet containing 1.5% cholesterol and 0.5% cholic acid and given a single subcutaneous injection of adjuvant (Mycobacterium butyricum) into the base of the tail. The animals were maintained for 8 weeks. Rats given the atherogenic diet showed markedly increased serum cholesterol levels, and all of those given the adjuvant injection developed severe polyarthritis. Cholesterol feeding tended to delay the onset of arthritis and remarkably suppressed the inflammatory response, particularly in the early stage of development. This may have been due to the lowered lipid peroxide levels in the serum of rats fed the atherogenic diet. Adjuvant arthritis together with cholesterol feeding markedly increased the cholesterol content of the aorta, whereas either treatment alone had little effect. The amounts of the connective tissue components and minerals in the aorta were not changed by both treatments. These results show that early atherosclerosis could be produced under the conditions used and that chronic inflammation and hypercholesterolemia are principal factors in the pathogenesis.

Animals↗
PubMed1986

Proteolytic activity and serum protease inhibitors in nasal secretions from adult patients with common colds.

Proteolytic activity and concentrations of serum protease inhibitors were measured in nasal secretions collected from 14 adult patients (6 males and 8 females) with common colds. Elastase concentration and fibrinolytic activity increased about three days after the onset of the colds, and there was a significant correlation between both values (p less than 0.01). Trypsin-like protease activity was very low. Of all serum protease inhibitors, inter-alpha-trypsin inhibitor could not be detected, and alpha 2-macroglobulin could be detected in only two cases. Variation of alpha 1-antitrypsin value was very similar to that of alpha 1-antichymotrypsin, and there was a significant correlation between alpha 1-antitrypsin and elastase (p less than 0.001). Phoretic patterns of crossed immuneelectrophoresis revealed the presence of alpha 1-antitrypsin-protease complex. alpha-protease inhibitors are major serum protease inhibitors in nasal secretions of persons with colds, and inhibit excess proteolytic activity of serine proteases. This protection is considered to be one of the major factors in preventing irreversible mucosal change.

Adult↗
PubMed1986

Significance of lysosomal proteases; cathepsins B and H in maxillary mucosa and nasal polyp with non-atopic chronic inflammation.

Tissue extracts from maxillary mucosa (MM) and nasal polyp (NP) with non-atopic chronic inflammation were applied to DEAE-Sepharose, and hydrolytic activity of lysosomal proteases (cathepsins B and H) was measured by the fluorometric assay. Hydrolytic activity of cathepsins B and H in MM, of which cathepsin B was a major one, was about 3.5 times as high as that in NP. Protein composition resembled in both extracts except for several apparent protein bands with high molecular weight observed in NP. These results suggest that in MM with chronic inflammation, mucosal destruction induced by excess lysosomal granuloproteases overwhelming protease inhibitors would occur, being much related to the formation of its irreversible lesion.

Cathepsin B↗
PubMed1985

Purification and characterization of tissue-type plasminogen activator in maxillary mucosa with chronic inflammation.

Tissue-type plasminogen activator (TPA) was purified from maxillary mucosa with chronic inflammation and compared with urokinase. Purification procedure consisted of the extraction from delipidated mucosa with 0.3M potassium acetate buffer (pH 4.2), 66% saturation of ammonium sulfate, zinc chelate-Sepharose, concanavalin A-Sepharose and Sephadex G-100 gel filtration chromatographies. The molecular weight of the TPA was approximately 58,000 +/- 3,000. Its activity was enhanced in the presence of fibrin and was quenched by placental urokinase inhibitor, but not quenched by anti-urokinase antibody. The TPA made no precipitin line against anti-urokinase antibody, while urokinase did. All these findings indicate that the TPA in maxillary mucosa with chronic inflammation is immunologically dissimilar to urokinase and in its affinity for fibrin.

Adult↗
PubMed1985

Partial purification and characterization of the tissue plasminogen activator in nasal mucosa and nasal polyp.

Tissue plasminogen activator was partially purified from the inferior turbinate and nasal polyp, and its biochemical properties were investigated. Similar TPA peak positions were seen in the gel filtration chromatography of both tissues, and the molecular weight was approximately 65,000, which was comparable to TPA of pig heart (55,000-60,000). Activity of TPA from inferior turbinate was higher than that from nasal polyp. TPA from both tissues was completely inhibited by trans-aminomethyl cyclohexane carboxylic acid, dithiothreitol, and diisopropylfluorophosphate and had similar inhibition profiles to TPA from pig heart. All these findings indicate that TPA from both tissues is undoubtedly a plasminogen-activating enzyme and serine-type protease and would be biochemically identical.

Chromatography, Gel↗
PubMed1985

Rheological properties of middle ear effusion and their role on mucociliary clearance.

The viscoelastic properties of freshly harvested middle ear effusion (MEE) from children were determined by an oscillating sphere magnetic rheometer and compared with transportability of MEE on mucus-depleted frog palate. The elastic modulus (G') at 1 Hz of MEE from 43 untreated ear was ranged from 1.9 to 1,790 dyn/cm2 and the mean value was 28.4 dyn/cm2. The dynamic viscosity (eta') at 1 Hz of the same samples was ranged from 0.2 to 146 poise with the mean value of 3.4 poise. A maximum value of transport was obtained at G' of about 20 dyn/cm2, and below this value there was a significant positive correlation between the transport rate and log G'. Above 20 dyn/cm2, the negative correlation between the transport rate and log G' was significant. A similar significant correlation between the transport rate and log eta' was observed.

Adolescent↗
PubMed1985

The significance of protease inhibitors in the pathogenesis of otitis media with effusion.

Concentration of alpha 1-antitrypsin (alpha 1-AT), alpha 1-antichymotrypsin (alpha 1-AChyT), inter-alpha-trypsin inhibitor (I-alpha-I), and alpha 2-macroglobulin (alpha 2-M) was measured in 27 serous middle ear effusions (MEEs) from 24 adult patients. The presence of protease-inhibitor complex was analyzed by crossed immunoelectrophoresis (CIEP). Mean concentration of alpha 1-AT was 361 +/- 90.0 mg/dl and was higher than that of other inhibitors: alpha 1-AChyT, 80.6 +/- 40.7; I-alpha-I, 21.3 +/- 21.5; alpha 2-M, 59.5 +/- 57.1. Molar concentration of alpha 2-M was the lowest. Most of alpha 1-AT and alpha 1-AChyT in MEEs were unsaturated; free inhibitors. Alpha-1-AT could be saturated by trypsin and elastase immediately, and only alpha 2-M could be saturated by papain (classical thiol protease). Serous MEEs have high anti-trypsin activity attributed to mainly free alpha 1-AT. Since level of alpha 2-M was very low, lysosomal thiol proteases could be one of the major proteases inducing proteolytic damage to middle ear mucosa.

Adult↗
PubMed1985

Alpha-actinin from sea urchin eggs: biochemical properties, interaction with actin, and distribution in the cell during fertilization and cleavage.

A protein similar to alpha-actinin has been isolated from unfertilized sea urchin eggs. This protein co-precipitated with actin from an egg extract as actin bundles. Its apparent molecular weight was estimated to be approximately 95,000 on an SDS gel: it co-migrated with skeletal-muscle alpha-actinin. This protein also co-eluted with skeletal muscle alpha-actinin from a gel filtration column giving a Stokes radius of 7.7 nm, and its amino acid composition was very similar to that of alpha-actinins. It reacted weakly but significantly with antibodies against chicken skeletal muscle alpha-actinin. We designated this protein as sea urchin egg alpha-actinin. The appearance of sea urchin egg alpha-actinin as revealed by electron microscopy using the low-angle rotary shadowing technique was also similar to that of skeletal muscle alpha-actinin. This protein was able to cross-link actin filaments side by side to form large bundles. The action of sea urchin egg alpha-actinin on the actin filaments was studied by viscometry at a low-shear rate. It gelled the F-actin solution at a molar ratio to actin of more than 1:20, at pH 6-7.5, and at Ca ion concentration less than 1 microM. The effect was abolished by the presence of tropomyosin. Distribution of this protein in the egg during fertilization and cleavage was investigated by means of microinjection of the rhodamine-labeled protein in the living eggs. This protein showed a uniform distribution in the cytoplasm in the unfertilized eggs. Upon fertilization, however, it was concentrated in the cell cortex, including the fertilization cone. At cleavage, it seemed to be concentrated in the cleavage furrow region.

Actinin↗
PubMed1985

Distribution of fluorescently labeled tubulin injected into sand dollar eggs from fertilization through cleavage.

Porcine brain tubulin labeled with fluorescein isothiocyanate (FITC) was able to polymerize by itself and co-polymerize with tubulin purified from starfish sperm flagella. When we injected the FITC-labeled tubulin into unfertilized eggs of the sand dollar, Clypeaster japonicus, and the eggs were then fertilized, the labeled tubulin was incorporated into the sperm aster. When injected into fertilized eggs at streak stage, the tubulin was quickly incorporated into each central region of growing asters. It was clearly visualized that the labeled tubulin, upon reaching metaphase, accumulated in the mitotic apparatus and later disappeared over the cytoplasm during interphase. The accumulation of the fluorescence in the mitotic apparatus was observed repeatedly at successive cleavage. After lysis of the fertilized eggs with a microtubule-stabilizing solution, fluorescent fibrous structures around the nucleus and those of the sperm aster and the mitotic apparatus were preserved and coincided with the fibrous structures observed by polarization and differential interference microscopy. We found the FITC-labeled tubulin to be incorporated into the entire mitotic apparatus within 20-30 s when injected into the eggs at metaphase or anaphase. This rapid incorporation of the labeled tubulin into the mitotic apparatus suggests that the equilibrium between mitotic microtubules and tubulin is attained very rapidly in the living eggs. Axonemal tubulin purified from starfish sperm flagella and labeled with FITC was also incorporated into microtubular structures in the same fashion as the FITC-labeled brain tubulin. These results suggest that even FITC-labeled heterogeneous tubulins undergo spatial and stage-specific regulation of assembly-disassembly in the same manner as does sand dollar egg tubulin.

Animals↗
PubMed1985

Plasma component of middle ear effusion evaluated by prekallikrein level.

Plasma leakage into middle ear was evaluated by the level of prekallikrein in middle ear effusions (MEE), measured by the fluorometric assay. Plasma leakage into middle ear is a major source of MEE, especially serous effusions. The degree of plasma leakage at the time of sampling is very low in mucoid effusions and varied in serous effusions. Active plasma leakage into middle ear would occur at the early restricted inflammatory phase in the middle ear.

Albumins↗
PubMed1985

Purification of glandular kallikrein in maxillary mucosa from humans suffering from chronic inflammation.

Glandular kallikrein was purified from human maxillary mucosa with chronic inflammation and its biochemical properties were characterized. The purification procedure consisted of extraction with 3 mol/l KCl, saturation of ammonium sulfate (66%), DEAE-Sepharose, arginine-Sepharose and Sephadex G-150 chromatographies. Maxillary mucosa with chronic inflammation contains considerable activity of glandular kallikrein, which is a serine protease with limited proteolytic activity and its biochemical properties resemble those of pancreatic kallikrein.

Adult↗
PubMed1984

Colcemid treatment of myeloma prior to cell fusion increases the yield of hybridomas between myeloma and splenocyte.

Effect of Colcemid treatment of myeloma (X63-Ag8-6.5.3.) prior to fusion with mouse spleen cell was studied in terms of hybridoma formation. Spleen cells from BALB/c mice immunized with various soluble antigens were fused with the myeloma cells by using polyethylene glycol solution. Colcemid treatment of myeloma cells prior to fusion increased the average number of hybridoma colonies per well by 26-570%. The yield of hybridomas producing antigen-specific antibodies was also higher with the Colcemid treatment. The results suggest that most of the proliferative hybridomas are formed by fusion of cells in the M-phase of the cell cycle.

Animals↗