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Y Doi

Publications and source records attributed to Y Doi.

At least 19 recordsLinked to original sources
PubMed2000

Dietary zinc deficiency decreases glutathione S-transferase expression in the rat olfactory epithelium.

Zinc deficiency leads to olfactory and gustatory dysfunction, but little is known about the underlying molecular mechanism of this phenomenon. We examined the effect of dietary zinc deficiency on the rat olfactory epithelium. Immunoreactivities of glutathione S-transferase (GST) mu, neuron-specific enolase (NSE) and proliferating cell nuclear antigen (PCNA), and in situ hybridization of GST mu mRNA in the olfactory epithelia were examined under different dietary zinc intake conditions. Adult male rats were fed a zinc-deficient (ZD) diet (0.5 mg zinc/kg diet), whereas control rats, including pair-fed (PF) and zinc-adequate (ad libitum consumption, AL) groups, were fed a zinc-adequate diet (58 mg zinc/kg diet) for 7 wk. We also examined the effect of zinc replacement (ZR) by subsequently feeding half of the ZD group a zinc-adequate diet for 5 wk after the initial 7-wk deprivation. No significant differences in immunoreactivity for NSE in olfactory epithelial receptor cells or for PCNA in basal cells were noted among groups. Intense GST mu immunoreactivity and hybridization signals were observed in olfactory supporting cells of AL, PF and ZR groups, but very minimal or no such signal was noted in ZD rats. Our findings indicated that zinc deficiency reduces GST mu expression in the supporting cells of rat olfactory epithelia but does not affect receptor cell proliferation or maintenance.

Actins↗
PubMed1999

Osteoclastic responses to various calcium phosphates in cell cultures.

Disks made of hydroxyapatite, beta-tricalcium phosphate, carbonate apatite, tetracalcium phosphate, alpha-tricalcium phosphate, dicalcium phosphate dihydrate, and octacalcium phosphate were incubated in osteoclastic cell cultures for 2 days. The first five salts were sintered and the last two were compressed before incubation. Osteoclasts resorbed only the sintered carbonate apatite disks. However, osteoclasts were able to resorb octacalcium phosphate disks that were preincubated for 1 day in medium without cells, indicating that surface conditioning was important for osteoclastic resorption of this calcium phosphate. Although resorption did not occur, medium calcium and phosphorus changed to an appreciable extent after a 2-day incubation of beta-tricalcium phosphate, tetracalcium phosphate, alpha-tricalcium phosphate, and dicalcium phosphate dihydrate. These changes in the medium calcium and phosphate concentrations could explain why osteoclasts appeared to have lost their activity on these calcium phosphate disks and were not capable of resorbing them. With hydroxyapatite disks no changes were observed in the medium calcium and phosphorus before and after incubation. Moreover, the osteoclasts appeared to be essentially the same as with the sintered carbonate apatite disks and with bone slices used as a control. Nevertheless, no pits or lacunae were observed on the hydroxyapatite disks, indicating that sintered carbonate apatite should be superior to sintered hydroxyapatite as a bioresorbable bone substitute.

Animals↗
PubMed1999

Co-expression of 3-ketoacyl-ACP reductase and polyhydroxyalkanoate synthase genes induces PHA production in Escherichia coli HB101 strain.

The Escherichia coli 3-ketoacyl-ACP reductase gene (fabGEc) was cloned using a PCR technique to investigate the metabolic link between fatty acid metabolism and polyhydroxyalkanoate (PHA) production. Three plasmids respectively harboring fabGEc and the poly-3-hydroxyalkanoate synthesis genes phaCAc and phaC1Ps from Aeromonas caviae and Pseudomonas sp. 61-3 respectively were constructed and introduced into E. coli HB101 strain. On a two-stage cultivation using dodecanoate as the sole carbon source, recombinant E. coli HB101 strains harboring fabGEc and phaC genes accumulated PHA copolymers (about 8 wt% of dry cell weight) consisting of several (R)-3-hydroxyalkanoate units of C4, C6, C8, and C10. It has been suggested that overexpression of the fabGEc gene leads to the supply of (R)-3-hydroxyacyl-CoA for PHA synthesis via fatty acid degradation.

3-Oxoacyl-(Acyl-Carrier-Protein) Reductase↗
PubMed1999

Injection of antisense oligos to nNOS into nucleus tractus solitarii increases blood pressure.

We investigated the cardiovascular effects of bilateral microinjection of antisense oligodeoxynucleotides (oligos) into the nucleus tractus solitarii (NTS) to neuronal nitric oxide synthase (nNOS) to suppress the expression of nNOS molecular biologically. In urethane-anesthetized, paralyzed Wistar-Kyoto rats, bilateral microinjection of nNOS antisense oligos (20 pmol in a 50nl volume) into the NTS produced a significant increase in mean arterial blood pressure at 30-60min after injection, compared with rats injected with nNOS sense or scrambled oligos. Immunohistochemical study demonstrated that nNOS immunoreactivity in the rat NTS was suppressed by nNOS antisense oligos. These results indicate that suppression of the nNOS gene using antisense in the NTS increases blood pressure.

Animals↗
PubMed1999

Polymorphism of the D12S391 microsatellite in a Japanese population sample.

Using the polymerase chain reaction (PCR), we studied the short tandem repeat (STR) polymorphism observed at the D12S391 locus. In 350 Japanese examined, 14 different alleles ranging from 209 bp to 261 bp were detected. Allele 18 (221 bp) showed the highest frequency at 0.30. Observed and expected values of respective genotypes satisfied the Hardy-Weinberg equilibrium (chi 2 = 24.08, P = 0.24, df = 20). In addition, 18 additional sequence structures (suballeles), were detected in this study. Within the suballeles, sequence variants, in which the initial repeat of (AGAT) was replaced with (AGGT), was found in five samples. It was found that the analysis of single-strand conformation polymorphism (SSCP) before sequence analysis was useful for distinguishing these suballeles.

Alleles↗
PubMed1999

Normal development of mice and unimpaired cell adhesion/cell motility/actin-based cytoskeleton without compensatory up-regulation of ezrin or radixin in moesin gene knockout.

Ezrin/radixin/moesin (ERM) proteins are general cross-linkers between the plasma membrane and actin filaments. Because their expression is regulated in a tissue-specific manner, each ERM protein has been proposed to have unique functions. On the other hand, experiments at the cellular level and in vitro have suggested their functional redundancy. To assess the possible unique functions of ERM proteins in vivo, the moesin gene located on the X chromosome was disrupted by gene targeting in embryonic stem cells. Male mice hemizygous for the mutation as well as homozygous females were completely devoid of moesin but developed normally and were fertile, with no obvious histological abnormalities in any of the tissues examined. In the tissues of the mutant mice, moesin completely disappeared without affecting the expression levels or subcellular distribution of ezrin and radixin. Also, in platelets, fibroblasts, and mast cells isolated from moesin-deficient mice, targeted disruption of the moesin gene did not affect their ERM-dependent functions, i.e. platelet aggregation, stress fiber/focal contact formation of fibroblasts, and microvillar formation of mast cells, without compensatory up-regulation of ezrin or radixin. These findings favor the notion that ERM proteins are functionally redundant at the cellular as well as the whole body level.

Actins↗
PubMed1999

Co-expression of polyhydroxyalkanoate synthase and (R)-enoyl-CoA hydratase genes of Aeromonas caviae establishes copolyester biosynthesis pathway in Escherichia coli.

Polyhydroxyalkanoate biosynthesis genes of Aeromonas caviae were expressed in Escherichia coli LS5218 (fadR atoC(Con)), and the polyhydroxyalkanoate-producing ability of the recombinants was investigated. A LS5218 strain harboring only phaCAc (polyhydroxyalkanoate synthase gene) did not accumulate any polyhydroxyalkanoate from dodecanoate in spite of the existence of translated polyhydroxyalkanoate synthase protein, whereas co-expression phaCAc and phaJAc ((R)-specific enoyl-CoA hydratase gene) resulted in the accumulation of P(3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymer up to 7-11 wt% of dry cell weight from octanoate and dodecanoate. These results indicated that both phaCAc and phaJAc are essential for E. coli LS5218 to establish the polyhydroxyalkanoate biosynthesis pathway from alkanoic acids. The copolyester content in the strain expressing both the genes under the lac promoter control reached to 38 wt% from dodecanoate. Enzyme assays suggest that efficient monomer formation via beta-oxidation by a high level expression of phaJAc was important to achieve a high polyhydroxyalkanoate content in the recombinant E. coli.

Acyltransferases↗
PubMed1999

Chronological study of the appearance of adenohypophysial cells in the ayu (Plecoglossus altivelis).

We previously reported the chronological appearance of adenohypophysial cells in freshwater teleosts using an immunocytochemical technique. The present study investigated the chronological appearance of adenohypophysial cells in the ayu, which is spawned and has its early development in brackish water, and the results were compared with those obtained in freshwater and seawater teleosts, as well as in other vertebrates. In the adult teleostean adenohypophysis, seven or eight types of secretory cells have been distinguished, each of which produce different hormones: prolactin (PRL), growth hormone (GH), thyroid stimulating hormone (TSH), gonadotropic hormones (GTH I and GTH II), adrenocorticotropic hormone (ACTH), melanophore stimulating hormone (MSH) and somatolactin (SL). In the pituitary of adult ayu, seven distinct types of glandular cells (PRL, GH, TSH, GTH, ACTH, MSH and SL cells) were identified. Chronologically, a few immunoreactive (ir)-PRL and ir-GH cells appeared in the ventral side of the pituitary one day before hatching. Then, just after hatching, ir-GTH cells were observed in the central to dorsal portion; ir-ACTH cells were found distributed in the anterior portion and some ir-MSH and a few ir-SL cells were seen in the posterior portion of the pituitary. Finally, a small number of ir-TSH cells were identified 50 days after hatching. These results differed from those obtained in other fishes previously reported with regard to the times of appearance of the PRL and GH cells. PRL cells appeared first, followed by GH cells in the freshwater teleosts, PRL and GH cells appeared at the same time in the brackishwater teleosts, while GH cells appeared first and PRL cells appeared last in the seawater teleosts. These results reflect the fact that PRL plays a major role in osmoregulation among freshwater teleosts, as compared with GH, which plays a similar role in seawater teleosts. It seems that both PRL and GH may play important roles in osmoregulation in brackishwater fish.

Adrenocorticotropic Hormone↗
PubMed1999

Substrate and binding specificities of bacterial polyhydroxybutyrate depolymerases.

The substrate specificities of three extracellular polyhydroxybutyrate (PHB) depolymerases from Alcaligenes faecalis (PhaZ Afa), Pseudomonas stutzeri (PhaZ Pst), and Comamonas acidovorans (PhaZ Cac), which are grouped into types A and B based on the position of a lipase box sequence in the catalytic domain, were examined for films of 12 different aliphatic polyesters. Each of these PHB depolymerases used was capable of hydrolyzing poly(3-hydroxybutyrate) (P(3HB)), poly(3-hydroxypropionate) (P(3HP)), poly(4-hydroxybutyrate) (P(4HB)), poly(ethylene succinate) (PESU), and poly(ethylene adipate) (PEA) but could not hydrolyze another seven polyesters. In addition, the binding characteristics of substrate binding domains from PhaZ Afa, PhaZ Cac, and PHB depolymerase from Comamonas testosteroni (PhaZ Cte) were studied by using fusions with glutathione S-transferase (GST). All of fusion proteins adsorbed strongly on the surfaces of polyester granules of P(3HB), P(3HP), and poly(2-hydroxypropionate) (P(2HP)) which was not hydrolyzed by the PHB depolymerases used in this study, while they did not bind on Avicel and chitin granules. The adsorption kinetics of the fusion proteins to the surface of P(3HB) and P(2HP) granules were found to obey the Langmuir isotherm. The cross-area per molecule of fusion protein bound to P(3HB) granules was estimated to be 12+/-4 nm2/molecule. It has been suggested that the active sites in catalytic domains of PHB depolymerases have a similar conformational structure, and that several amino acids in substrate-binding domains of PHB depolymerases interact specifically with the surface of polyesters.

Adsorption↗
PubMed1999

Renal complications in patients with diabetes mellitus associated with an A to G mutation of mitochondrial DNA at the 3243 position of leucine tRNA.

The substitution of guanine for adenine at position 3243 of the leucine tRNA gene of mitochondrial DNA was originally described in association with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes). Diabetes mellitus associated with the mutation (mitochondrial diabetes) is a different phenotype from MELAS. We identified 11 patients with the mutation among 385 Japanese diabetic patients: two had MELAS and nine had mitochondrial diabetes. We present data on a male patient with mitochondrial diabetes who developed the nephrotic syndrome at the age of 23. Light microscopy revealed mesangial expansion, PAS-positive deposits and segmental sclerosis in the glomeruli. Scattered mesangial electron-dense deposits and thickening of the basement membrane were found on electron microscopy, suggesting that diabetic glomerulosclerosis accompanied by focal glomerulosclerosis (FGS). Mitochondrial diabetes may pre-dispose patients to renal complications, including forms of glomerulonephritis, such as FGS.

Adult↗
PubMed1999

Reduced plasma transforming growth factor-beta1 levels in patients with chronic hepatitis C after interferon-alpha therapy: association with regression of hepatic fibrosis.

BACKGROUND/AIM: Transforming growth factor-beta1 is involved in liver fibrosis. Our aim was to examine the association of plasma transforming growth factor-beta1 levels with the degree of liver fibrosis. METHODS: We analyzed plasma transforming growth factor-beta1 levels in 43 patients with chronic hepatitis C treated with interferon-alpha using a transforming growth factor-beta1 ELISA. The content of transforming growth factor-beta1 in liver tissue obtained by needle biopsy (n=13) was also analyzed. The degree of liver fibrosis was assessed histologically and morphometrically. RESULTS: Plasma transforming growth factor-beta1 levels were significantly correlated with transforming growth factor-beta1 content in liver tissue (r=0.83, p<0.001), indicating that plasma levels correspond with tissue cytokine. Plasma transforming growth factor-beta1 levels in patients (8.1+/-1.1 ng/ml) before interferon-a therapy were significantly higher than in controls (1.9+/-0.3 ng/ml) (p<0.01). Plasma levels were significantly correlated with the degree of fibrosis (p<0.01). Plasma transforming growth factor-beta1 levels were significantly decreased in sustained responders (from 5.2+/-1.0 ng/ml to 2.9+/-0.7 ng/ml), relapsed patients (from 9.8+/-2.0 ng/ml to 3.4+/-0.6 ng/ml), and nonresponders (from 9.3+/-2.1 ng/ml to 3.9+/-0.9 ng/ml) at the end of therapy (p<0.05 for all comparisons). Significant regression of liver fibrosis after therapy was observed in both sustained responders and nonresponders (p<0.05 for both). CONCLUSIONS: These observations suggest that plasma transforming growth factor-beta1 levels appear to be associated with the degree of liver fibrosis.

Aged↗
PubMed1999

Immunoreactivity of endothelins and endothelin receptor in the stria vascularis of the mouse cochlea.

Immunoreactivities of endothelin-1, endothelin-3, endothelin receptor type A, and Na,K-ATPase were investigated in the stria vascularis of adult male WBB6F1 +/+ mice and in that of W/Wv mutants lacking strial intermediate cells. In the +/+ mice, electron microscopic immunoreactivity for the endothelins was seen on the rough endoplasmic reticulum, Golgi apparatus, cytoplasmic vesicles and lysosomes exclusively in the strial intermediate cells by the postembedment method. Immunoreactive endothelin receptor A was localized along the plasma membrane of strial marginal cells of both wild and mutant types although the immunoreactivity of the latter was much less than that of the former by the preembedment method. These findings suggest that the endothelins, which are produced in the strial intermediate cells, may play a role in the maintenance of the stria vascularis function in the +/+ mice. Since the plasma membrane of the marginal cells of the W/Wv mice, which do not generate a high positive endocochlear potential, also showed immunoreactivity for Na,K-ATPase, it seems likely that the endothelins are involved in the activation of sodium pump of the strial marginal cells by mediation of endothelin receptor A. In addition, the role of lysosomes in the crinophagy of the endothelins in the strial intermediate cells is proposed in the +/+ mice.

Animals↗
PubMed1999

Lifestyles and sleep disorders among the Japanese adult population.

To clarify the effects of daily stress, habitual exercise, drinking and smoking on the prevalence of sleep disorders, we selected 4000 residents (> or =20 years) in Japan by stratified random sampling and carried out structured interviews (response rate 75.8%). Frequencies of sleep disorders (difficulty initiating sleep: DIS; difficulty maintaining sleep: DMS; early morning awakening and hypnotic medication use) were treated as dependent variables. Significant effects of stress were prevalent in all sleep disorders. Habitual exercise had significant negative association with DIS and DMS. Drinking and smoking did not affect sleep disorders.

Adult↗
PubMed1999

Salmonid olfactory system-specific protein (N24) exhibits glutathione S-transferase class pi-like structure.

A salmonid olfactory system-specific protein (N24) that has been identified in lacustrine sockeye salmon (Oncorhynchus nerka) was characterized by biochemical and molecular biological techniques. N24 is a homodimer, and the intact molecular mass is estimated as approximately 43.3 kDa by gel filtration. Furthermore, N24 was located only in the cytosolic fraction of the olfactory tissues as determined by subcellular fractionation. cDNA encoding the lacustrine sockeye salmon N24 was isolated and sequenced. This cDNA contained a coding region encoding 216 amino acid residues and the molecular mass of this protein is calculated to be 242,224.77. The protein and nucleotide sequencing demonstrates the existence of a remarkable homology between N24 and glutathione S-transferase (GST; EC 2.5.1.18) class pi enzymes. Northern analysis showed that N24 mRNA with a length of 950 bases is expressed in lacustrine sockeye salmon olfactory epithelium. Olfactory receptor cells showed strong hybridization signals for N24 mRNA in the olfactory epithelium. N24 demonstrated glutathione binding activity in affinity-purified GST column experiments. The present study describes for the first time cDNA cloning of GST in fish olfactory epithelium.

Animals↗
PubMed1999

Evaluation of an enzyme-linked immunosorbent assay based on binding inhibition for type-specific quantification of poliovirus neutralization-relevant antibodies.

To detect neutralization-relevant antibodies against 3 types of poliovirus (PV) without using tissue cultures and live viruses, an enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibody-binding inhibition was evaluated using sera from 80 vaccinated Japanese children and 60 Pakistani poliomyelitis patients. Compared with the neutralization test, the sensitivity of the inhibition ELISA was 100% (111/111) for detection of anti-PV1 antibody, 98.3% (118/120) for anti-PV2, and 96.5% (82/85) for anti-PV3, and the specificity was 93.1% (27/29), 100% (20/20), and 92.7% (51/55), respectively. Thus, the inhibition ELISA showed excellent potential as a seroepidemiologic tool in both vaccinated and naturally-infected populations.

Animals↗