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Y Araki

Publications and source records attributed to Y Araki.

At least 19 recordsLinked to original sources
PubMed1995

Purification and characterization of two forms of beta-D-galactosidase from rat epididymal luminal fluid: evidence for their role in the modification of sperm plasma membrane glycoprotein(s).

Previous studies from this laboratory have identified rat epididymal luminal fluid acid beta-D-galactosidase activity which also optimally hydrolyses a glycoprotein substrate at neutral pH [Skudlarek, Tulsiani and Orgebin-Crist (1992) Biochem. J. 286, 907-914]. We have now separated the luminal fluid beta-D-galactosidase into two molecular forms by ion-exchange chromatography on a column of DE-52. The separated enzyme activities were purified to an apparent homogeneity by molecular-sieve chromatography followed by affinity chromatography on a column of immobilized p-nitrophenyl beta-D-thiogalactopyranoside. The purified forms, when resolved by SDS/PAGE under reducing conditions, showed apparent molecular masses of 84 and 97 kDa. Kinetic studies, including a pH-dependent substrate preference and pH-dependent association/dissociation, disclosed no differences between these two forms. The two forms had identical N-terminal amino acid sequences. However, the 97 kDa form contained much more total carbohydrate and sialic acid than the 84 kDa form. The carbohydrate moieties in the two forms were assessed by comparing their size on SDS/PAGE before and after treatment with endo-enzymes. The removal of N-linked glycans by treatment with N-glycanase or endoglycosidase F generated de-N-glycosylated polypeptides of an apparent molecular mass of 70 kDa, and indicated that the two forms contained varying amounts of asparagine (N)-linked high mannose/hybrid-type and biantennary complex-type oligosaccharides. This result and the fact that the two molecular forms had identical N-terminal amino acid sequences indicated that the two forms probably have identical or very similar polypeptides. The potential role of the enzyme in modification of sperm plasma membrane (PM) glycoproteins was examined by resolving caput sperm PM proteins (before and after treatment in vitro of the membranes with the purified beta-D-galactosidase) on SDS/PAGE, followed by staining with peanut agglutinin (PNA), a lectin which preferentially binds to Gal beta 1,3GalNAc-linkages found in O-linked glycoproteins. The evidence presented in this report has indicated that a PNA-positive glycoprotein of an apparent molecular mass of 135-150 kDa present on the caput (but not cauda) sperm PM is degalactosylated by the digestion in vitro of the membranes with purified luminal fluid beta-D-galactosidase. This result suggests a possible role for the epididymal luminal fluid beta-D-galactosidases.

Amino Acid Sequence↗
PubMed1995

Intraosseous ganglion.

A 48-year-old man presented with pain in the right wrist. A roentgenogram showed symmetrically located, well-demarcated lucencies in both scaphoids. These lesions showed homogeneous intermediate signal intensity on T1-weighted MR images and homogeneous high signal intensity on T2*-weighted MR images. Histopathological analysis revealed the lesion in the right hand as an intraosseous ganglion. The reason why the lesions were located on the palmar side is discussed.

Bone Cysts↗
PubMed1995

Cranial MRI in chronic thinner intoxication.

We studied a 19-year-old man with thinner and toluene poisoning for 5 years by CT and MRI. Symmetrical lesions were seen in the basal ganglia and cingulate gyri.

Administration, Inhalation↗
PubMed1995

Molecular cloning and characterization of a mouse oviduct-specific glycoprotein.

In the present study, we have isolated the cDNA for the mouse oviduct-specific glycoprotein (MOGP) by screening the mouse oviduct cDNA library with the bovine oviduct-specific glycoprotein (BOGP)-cDNA probe and by the 5' rapid amplification of the cDNA end (5'RACE). The total length of cDNA was determined to be 2525 base pairs (bp) by sequence analysis. The coding region contained 2163 bp translating to 721 amino acids. Based on comparisons with the N-terminal amino acid sequences of purified-BOGP and of hamster oviduct-specific glycoprotein (oviductin), it was inferred that the derived amino acid sequence contained a signal peptide region of 21 amino acids and a mature MOGP (core protein) region of 700 amino acids (76,515 daltons). It was also inferred that the mature MOGP contained three potential N-linked glycosylation sites and 24 possible O-linked glycosylation sites, and had the unique seven-residue repeat sequence (21 repeats) within the predicted sequence in the C-terminal side. The amino acid sequence of a portion of MOGP was highly homologous to that of BOGP (71% identity), baboon oviduct-specific glycoprotein (61% identity), and human oviduct-specific glycoprotein (77% identity). Significant homologies were also observed with two mammalian secretory proteins that were reported as a mammalian member of a chitinase protein family. Northern blot hybridization with a DIG-labeled probe indicated that a single message of 2.8 kb was present in total RNA prepared from oviductal tissue. In situ hybridization using MOGP-cDNA showed that a MOGP message was only detected in the oviductal epithelial cells. These results strongly suggest that a significant degree of homology exists among oviduct-specific glycoproteins of various mammalian species.

Amino Acid Sequence↗
PubMed1995

Molecular characterization of a hamster oviduct-specific glycoprotein.

There is growing evidence that the oviduct is not a passive conduit for gamete and embryo transport but serves a function for the gametes and/or embryos. The oviductal epithelium secretes one or more specific glycoproteins that associate with the egg after ovulation. Several published reports including our preliminary studies have suggested that the egg-associating glycoprotein(s) from the oviduct exists in several mammalian species including golden hamster. However, little or almost no biochemical characterization of the hamster oviduct-specific glycoprotein (HOGP) has been reported. To analyze the molecular structure of the HOGP in detail, we have attempted molecular cloning of cDNA corresponding to HOGP. A cDNA library constructed from the hamster oviduct in the phage vector lambda ZAPII was screened with digoxigenin-labeled, baboon oviduct-specific glycoprotein cDNA as the probe. A single positive clone was isolated, and the nucleotide sequence of the isolated cDNA was determined. Rapid amplification of cDNA end was carried out to obtain a proximal 5' cDNA end of the clone. The cDNA clone consisted of 2387 bp, and the coding region contained 2013 bp translating to 671 amino acids. The amino acid sequence deduced from the cDNA sequence confirmed the chemically determined NH2-terminal sequence of a HOGP and suggested that the derived amino acid sequence contained a signal peptide region (21 amino acids) and 650 amino acids (70,890 daltons) of the mature form of the HOGP region. The amino acid sequence of HOGP appeared to have eight potential N-glycosylation sites. Northern blot analysis revealed that a single message of approximately 2.5 kb was present in oviductal RNA but not in the RNA of several other hamster tissues. The HOGP showed high amino acid sequence homology with baboon, bovine, and human oviduct-specific glycoprotein. These results demonstrate that an oviduct-specific glycoprotein homologue gene exists in various mammalian species including rodent.

Amino Acid Sequence↗
PubMed1994

Usefulness of magnetic resonance imaging for detecting intrasubstance tear and/or degeneration of lateral discoid meniscus.

In order to determine the usefulness of magnetic resonance imaging (MRI) for detection of intrasubstance tears or degeneration of the lateral discoid meniscus, we compared findings obtained with MRI with those of histological examination. Sixty-four symptomatic lateral discoid menisci were studied using MRI before surgical treatment. Of these, 18 (28%) met the criteria that MRI signals did not extend to the surface and that no visible tears were observable at arthroscopy. Findings of intrameniscal regions of high signal intensity and flattening in shape on MR images were found to represent intrasubstance tears or degeneration not detected at arthroscopy. Our findings thus demonstrate that MRI is more sensitive than arthroscopy in the detection of intrasubstance pathologies of the lateral discoid menisci.

Adolescent↗
PubMed1994

An extra phosphorylation of Na+,K(+)-ATPase by paranitrophenylphosphate (pNPP): evidence for the oligomeric nature of the enzyme.

Paranitrophenylphosphate (pNPP) induced fluorescence changes in fluorescence isothiocyanate (FITC)-labeled Na+,K(+)-ATPase preparations. The extents of changes were similar to those induced by acetylphosphate (AcP) accompanying accumulation of a K(+)-sensitive phosphoenzyme (E2P) and an ouabain bound phosphoenzyme in the presence of Mg2+ and 16 mM Na+. Phosphoenzymes formed from [32P]pNPP were shown to turn over. The ratio of the maximum amount of the phosphoenzyme formed from pNPP to that of the phosphoenzyme formed from ATP and that of the ouabain-enzyme complex under steady-state conditions was shown to be close to 1:0.5:1. Such extra phosphorylation has hitherto only been observed in a transient state with the additions of high concentrations of ATP [Peluffo, R.D., Garrahan, P.J., and Rega, A. (1992) J. Biol. Chem. 267, 6596-6601]. Our data are compatible with the simultaneous presence of high and low affinity ATP-binding sites in Na+,K(+)-ATPase [Hamer, E. and Schoner, W. (1993) Eur. J. Biochem. 213, 743-748]. The maximum amount of paranitrophenol-sensitive fraction to synthesize [32P]pNPP in fully accumulated ADP-sensitive phosphoenzyme (E1P) from [32P]ATP was around 1/4 of the amount of ouabain-enzyme complex. These data and others indicate that a much higher degree of oligomerization, rather than (alpha beta)2, may be the functional unit of the enzyme in the membranes.

Adenosine Triphosphate↗
PubMed1994

O-linked trisaccharide and N-linked poly-N-acetyllactosaminyl glycans are present on mouse ZP2 and ZP3.

Mammalian oocytes are surrounded by an extracellular glycocalyx, the zona pellucida (ZP). In the mouse, the ZP is composed of three glycoproteins, designated mZP1, mZP2, and mZP3. Extensive studies in this species have resulted in the identification of primary (mZP3) and secondary (mZP2) receptors for spermatozoa. In this paper we present evidence for the occurrence of poly-N-acetyllactosaminyl glycans and an O-linked trisaccharide on mZP2 and mZP3. When exhaustively digested with endo-beta-galactosidase, an enzyme known to cleave repeating units of acetyllactosamine (3Gal beta 1, 4GlcNAc beta 1), mZP2 and mZP3 showed an apparent reduction in size by 23 kDa and 16 kDa, respectively. Experimental evidence included in this report indicates that polylactosaminyl glycans are present on N-linked sugar chains. In addition, O-linked sugar chains of mZP3 have been characterized. First, treatment of de-N-glycosylated mZP3 with O-glycanase in the presence of exo-glycosidases (sialidase, alpha-L-fucosidase, and N-acetylglucosaminidase) caused an apparent reduction in its size by 2-3 kDa as determined by SDS-PAGE. Second, treatment of the de-N-glycosylated mZP3 with mild alkali in the presence of 1 M NaB3H4 released radiolabeled oligosaccharide (OS) that eluted from a high-resolution Bio-Gel P-4 column at the position of a trisaccharide. The radiolabeled OS had the following structure: GlcNAc-->Gal beta 1,3GalNAcol. The structure was established by sizing on the Bio-Gel P-4 column, followed by examination of the susceptibility of the OS to exo-glycosidases and by its absorbability to immobilized lectin (PNA). Potential roles of N-linked and O-linked sugar chains in sperm-egg interaction are herein discussed.

Amino Sugars↗
PubMed1994

Effects of titanium nitride coatings on surface and corrosion characteristics of Ni-Ti alloy.

The structure of a titanium nitride film coated by arc ion plating on a Ni-50Ti shape memory alloy was characterized by X-ray photoelectron spectroscopy (XPS). The corrosion behavior of the titanium nitride-coated Ni-50Ti alloy was examined in 0.9% NaCl solution by potentiodynamic polarization measurements and a polarization resistance method. XPS spectra showed that the titanium nitride film consisted of three layers, a top layer of TiO2, a middle layer of TiNx (x > 1), and an inner layer of TiN. The passive current density for the titanium nitride-coated alloy was approximately two orders of magnitude lower than that of the polished alloy in the potential range from the free corrosion potential to +500 mV (vs. Ag/AgCl). Pitting corrosion associated with breakdown of the coated film occurred above this potential. The polarization resistance data also indicated that the corrosion rate of the titanium nitride-coated alloy at the free corrosion potential (+50-+100 mV) was more than one order of magnitude lower than that for the polished alloy.

Corrosion↗
PubMed1994

A pitfall in detection of intracranial unruptured aneurysms on three-dimensional phase-contrast MR angiography.

We report three cases of intracranial unruptured aneurysm evaluated with MR angiography using both three-dimensional time-of-flight and three-dimensional phase-contrast techniques. It has been said that the phase-contrast technique has advantages over the time-of-flight technique in the detection of intracranial aneurysms. However, in our three cases, three-dimensional time-of-flight MR angiography clearly showed the intracranial unruptured aneurysms, but three-dimensional phase-contrast MR angiography failed to show them.

Adult↗
PubMed1993

Effect of beta-adrenergic receptor antagonists on nicotine-induced tail-tremor in rats.

The effects of various beta-adrenergic receptor antagonists on nicotine-induced tail-tremor were investigated in rats. Atenolol (5 and 10 mg/kg, IP), arotinolol (5 and 10 mg/kg, IP), and carteolol (5 and 10 mg/kg, IP), hydrophilic beta-adrenergic receptor antagonists, did not affect the tail-tremor induced by nicotine given at a dose of 0.5 mg/kg SC. However, propranolol (5-20 mg/kg, IP) and pindolol (5-20 mg/kg, IP), nonselective and lipophilic beta-adrenergic receptor antagonists, did suppress the tail-tremor dose dependently. In contrast, metoprolol (5-20 mg/kg, IP), lipophilic and beta 1-selective adrenergic receptor antagonists, did not show such an effect. These results suggest that nicotine-induced tail-tremors may be mediated through central beta 2-adrenergic receptors as an appearance and developmental mechanism.

Adrenergic beta-1 Receptor Antagonists↗
PubMed1993

Chronic nicotine treatment potentiates behavioral responses to dopaminergic drugs in rats.

In the present study, the behavioral effects of apomorphine, methamphetamine, and haloperidol were examined in nicotine-treated rats. All animals were SC administered nicotine at a dose of 0.5 mg/kg or saline once daily for 14 days. Hyperlocomotion induced by apomorphine (0.2 mg/kg, IP) and methamphetamine (1.0 mg/kg, IP) was greater in nicotine-treated rats than in control rats. Stereotyped behaviors induced by apomorphine (1.0 mg/kg, IP) and methamphetamine (5.0 mg/kg, IP) were also potentiated in nicotine-treated rats. However, the incidence of catalepsy induced by haloperidol (0.25-1.5 mg/kg, IP) was slightly lower in nicotine-treated rats. These results suggest that chronic nicotine treatment may increase the susceptibility of the dopaminergic system to dopaminergic drugs.

Animals↗
PubMed1993

Soluble P-selectin is present in normal circulation and its plasma level is elevated in patients with thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome.

P-selectin is an integral membrane glycoprotein stored in the secretory granules of platelets and endothelial cells. To determine whether soluble P-selectin may be present in the circulation of healthy humans, we used a sandwich immunoassay to assess citrated plasma from 50 subjects. P-selectin was present in concentrations ranging from 19 to 521 ng/ml (mean +/- SD = 121 +/- 84 ng/ml). The apparent molecular weight of P-selectin immunoisolated from platelet-poor plasma was similar to that of the detergent-soluble form isolated from platelet membrane. Plasma levels of P-selectin were unaffected by the following procedures: (1) drawing of blood in the presence of protease inhibitors; (2) stimulation of platelet-rich plasma with aggregating agents; (3) ultracentrifugation at 100,000 g for 120 min at 4 degrees C or filtration through a 0.22 micron membrane; or (4) preincubation of platelet-poor plasma with immobilized anti-platelet glycoprotein Ib monoclonal antibodies. It appeared that plasma P-selectin did not result from the in vitro activation of platelets, nor was it derived from platelet microparticles. We also found that plasma P-selectin levels were significantly elevated in patients with thrombotic thrombocytopenic purpura (12 patients, 332 +/- 184 ng/ml, P < 0.001) and haemolytic uraemic syndrome (17 patients, 297 +/- 191 ng/ml, P < 0.0001), as compared to the normal levels. Thus, these data should facilitate the study of the pathophysiological significance of circulating P-selectin.

Adult↗
PubMed1993

Expression of dipeptidyl aminopeptidase IV activity in human lung carcinoma.

Dipeptidyl aminopeptidase IV (DAP IV) staining was examined in various histological types of lung carcinomas to evaluate this enzyme activity. A total of 45 lung carcinomas were examined for their enzyme activity. Almost all (93.1%) cases of adenocarcinoma were positive for DAP IV activity, whereas all cases of squamous cell carcinoma, small cell carcinoma, large cell carcinoma and carcinoid were negative. DAP IV activity of microsomes in lung carcinomas was significantly higher in papillary adenocarcinomas than in squamous cell carcinomas. These data suggest that DAP IV may be a good marker to distinguish adenocarcinoma from other histological types of lung carcinoma.

Adenocarcinoma↗
PubMed1992

[Semidiscoid lateral meniscus].

We propose a new entity known as "semidiscoid lateral meniscus" of the knee. The diagnostic criteria for semidiscoid lateral meniscus is the appearance on a thin-sliced axial 3-D image of a crescent-shaped meniscus whose transverse width is within 11.6 mm to 14.3 mm on the coronal image. These numerical values were calculated by discriminant analysis. A retrospective review of MR examinations of the knees revealed 15 patients (15 knees) with this entity. These patients were our subjects. Of these 15 patients, complicated lateral meniscal tears were seen in only three cases. Nine knees were free from complications, and five were asymptomatic. Six patients were examined with MR on the contralateral side, and discoid lateral menisci were revealed in all cases. Thus semidiscoid lateral meniscus shows a cross-relationship with discoid menisci.

Adolescent↗
PubMed1992

[MR angiography enhanced by sodium acetazolamide].

We tried to use sodium acetazolamide to enhance MR angiography (MRA). Sodium acetazolamide, one of carbonic anhydrase inhibitors, has an effect to increase regional cerebral blood flow. We made a direct comparison between pre and post enhanced MRA (both 3D-TOF and 3D-PC techniques). MRA after administration of sodium acetazolamide could depict more details of cortical branches without enhancement of back-ground. So we recommend this simple method to be used widely in any examination of MR angiography.

Acetazolamide↗
PubMed1992

A monoclonal antibody-based enzyme immunoassay for human GMP-140/P-selectin.

Two hybridoma cell lines producing monoclonal antibodies WGA-1 and PL7-6, reactive only with thrombin-stimulated human platelet have been established. Both these antibodies were investigated for their specific reactivity against GMP-140, based on the amino acid composition analysis of immunopurified antigen and N terminal amino acid sequencing of its protease fragments. A two-site enzyme immunoassay for quantification of human GMP-140 was developed using WGA-1 monoclonal antibody immobilized on 96-well microplates and horseradish peroxidase-labeled PL7-6 monoclonal antibody as detector. The assay was able to measure GMP-140 in serum and plasma with a sensitivity of about 5 ng/ml and a precision better than 10%. This assay will be useful for the detection of GMP-140 derived from platelets or endothelium in biological fluids and tissue extracts.

Amino Acid Sequence↗