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Y Nagae

Publications and source records attributed to Y Nagae.

At least 19 recordsLinked to original sources
PubMed2000

Memory of chirality in diastereoselective alpha-alkylation of isoleucine and allo-isoleucine derivatives.

[reaction: see text] alpha-Methylation of 3 gave 5 as a major product whereas 4 gave 6 predominantly, although both 3 and 4 have an (S)-chiral center at C(3). This indicates that chirality at C(2) in 3 and 4 was memorized in the corresponding intermediate enolates and the induced chirality made a major contribution in the stereochemical course of the reaction, while chirality at the adjacent chiral center C(3) had little effect.

Alkylation↗
PubMed2000

Optical coherence tomography patterns of choroidal osteoma.

PURPOSE: To determine the optical coherence tomographic images that are commonly observed in eyes with choroidal osteoma (choroidal ossification). METHODS: Three patients with choroidal osteoma were examined by optical coherence tomography. RESULTS: We found two optical coherence tomographic patterns in the eyes with choroidal osteoma. First, multiple tracks of high refractivity were present posterior to the tumor lesion. Second, thick and irregular plate-like, high-signal intensity areas were present in the choroid in the region of the tumor. CONCLUSIONS: Optical coherence tomography can be useful in the diagnosis of choroidal osteoma.

Adult↗
PubMed2000

Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 4). Fadrozole hydrochloride: an oral 2/4-week male reproductive organ toxicity study.

Doses of 0, 30 and 60 mg/kg/day of fadrozole hydrochloride (Afema: non-steroidal aromatase inhibitor, antitumor agent) were given perorally by gavage to HanIbm WIST male rats from 6 or 8 weeks of age for 2 weeks, and from 6 weeks of age for 4 weeks. In all treatment groups, reduced weights of seminal vesicle, prostate and epididymis, and degeneration/necrosis of the pachytene spermatocytes in stages VII or VIII seminiferous tubules, were dose-relatedly observed. Effects could also be assessed quantitatively by staging analysis with the result of a reduction in the numbers of stage VII pachytene spermatocytes at 30 and 60 mg/kg/day. Epididymal sperm examination revealed no treatment-related changes in any groups. The effects of 4-week treatment on male reproductive organs were similar to those of 2-week treatment at the same dose levels, except for the weights of seminal vesicle and prostate, which were more reduced by 4-week treatment than by 2-week treatment. There was no notable difference in detectability of toxicity in male reproductive organs between 2-week treatment from 6 weeks of age and 2-week treatment from 8 weeks of age. It was concluded that the changes observed in the rat male reproductive organs following 4 weeks of treatment with fadrozole hydrochloride could be detected also with 2 weeks of treatment.

Administration, Oral↗
PubMed1999

Molecular cloning and characterization of two sets of alpha-theta genes in the rat alpha-like globin gene cluster.

The highly heterogeneous rat hemoglobin system was investigated at the gene level. Two regions of the alpha-like globin gene cluster from a Wistar rat were isolated. Four lambda Dash recombinant clones carrying rat alpha-like globin genes were localized on two distinct gene regions. A region of approximately 16kb was found to contain the 5'-IIalpha1-psi theta 1-3' loci, and another of approximately 24kb the 5'-IIalpha2-psi theta2-psiI alpha3-3' loci. Both IIalpha1 and IIalpha2 are considered to be active, coding the IIalpha-globin chain. The nt sequences of IIalpha1 and IIalpha2 are identical except for six nt in the non-coding region. The psiI alpha3 locus is a truncated pseudogene. The putative promoter region of an alpha-like globin gene is joined directly to the third exon, homologous to that of Ialpha-globin cDNA. psi theta1 and psi theta2 are also pseudogenes, as evidenced by several deletions located in the protein-coding regions of these loci. The psi theta1 and psi theta2 loci exhibit extensive homology, but the restriction maps of these genes and their flanking regions differ considerably. Genomic Southern blot analyses of the total liver DNA from six rats showed the existence of three theta-globin-related genes, including psi theta1 and psi theta2. These results indicate that the two gene regions investigated are not allelic variants, but may be generated by block duplication. This is the first report of the existence of rodent theta-globin genes.

Animals↗
PubMed1999

Organization, structure, and evolution of the nonadult rat beta-globin gene cluster.

The beta-globin gene cluster of Wistar rat was extensively cloned and the embryonic genes were mapped and sequenced. Four overlapping lambda Dash recombinant clones cover about 31 kb and contain four nonadult beta-globin genes, 5'-epsilon1-gamma1-gamma2-psigamma3-3'. The epsilon1 and gamma2 are active genes, since their protein products were detected in the fetal stage of the rat (Iwahara et al., J Biochem 119:360-366, 1996). The gamma1 locus might be a pseudogene, since the ATA box in the promoter region is mutated to GTA; however, no other defect is observed. The psigamma3 locus is a truncated pseudogene because a 19-base deletion, which causes a shift of the reading frame, is observed between the second nucleotide of the putative codon 68 and codon 76. A sequence comparison suggests that the psigamma3 might be produced by a gene conversion event of the proto-gamma-globin gene set. Possible histories of the evolution of rat nonadult beta-globin genes are discussed.

Amino Acid Sequence↗
PubMed1998

[The diagnostic significance of polymerase chain reaction for ocular samples in viral retinitis].

During the past two years we studied the incidence of infection by eight members of the herpesvirus family in ocular samples (tear fluid, the aqueous, and the vitreous) using the polymerase chain reaction (PCR). A total of 31 ocular samples were collected from 22 eyes of 13 patients. The series comprised five cases of acute retinal necrosis, four of cytomegalovirus retinitis, three of proliferative diabetic retinopathy, and one of ocular malignant lymphoma. In 12 eyes of 9 patients with viral retinitis, causative viral DNA was detected either from the tear fluid (1/12, 8%), the aqueous (6/7, 86%), or the vitreous (1/1, 100%). In the fellow eyes free of viral retinitis, no viral DNA was detected in the samples (6 of tear fluid and one of the aqueous). Out of the other 4 patients without viral retinitis, viral DNA was detected in one patient with ocular malignant lymphoma. The findings show that PCR is a useful and sensitive method in the diagnosis of viral retinitis, but that it may give false positive results. The aqueous and the vitreous samples gave more positive results than tear fluid.

DNA, Viral↗
PubMed1996

Progressive outer retinal necrosis after bone marrow transplantation.

PURPOSE: To describe a case of progressive outer retinal necrosis in a human immunodeficiency virus-negative immunosuppressed patient undergoing treatment for graft-versus-host disease after bone marrow transplantation. METHOD: Onset, course, and outcome of the patient's eye disease were analyzed. RESULTS: Findings and course were typical for the recently described progressive outer retinal necrosis syndrome. CONCLUSION: Progressive outer retinal necrosis is not limited to the acquired immunodeficiency syndrome but may occur in patients immunocompromised because of other conditions.

Adolescent↗
PubMed1995

Purification, characterization, and cloning of a heme-binding protein (23 kDa) in rat liver cytosol.

A heme-binding protein (designated HBP23) has been purified from rat liver cytosol using heme-affinity chromatography and either reverse-phase high-performance liquid chromatography or sequential ion-exchange chromatography. The protein (23 kDa) binds heme with an affinity (Kd = 55 nM) higher than that of the abundant cytosolic heme-binding proteins, heme-binding protein (HBP)/liver fatty acid-binding protein (L-FABP) and the glutathione S-transferases (GSTs) (Kd = 100-200 nM). HBP23 is present in the cytosol of liver, kidney, spleen, small intestine, and heart, with the liver showing the highest content. A cDNA coding the 23-kDa protein was cloned using reverse transcription polymerase chain reaction with degenerative oligonucleotides derived from partial amino acid sequences. The cloned cDNA encoded 199 amino acids, and its amino acid sequence showed no homology to HBP/L-FABP, GSTs, or any other heme-binding proteins or hemeproteins. Homology search showed that HBP23 is highly homologous to mouse macrophage 23-kDa stress protein, which is inducible by oxidant stress in peritoneal macrophages [Ishii, T., Yamada, M., Sato, H., Matsue, M., Taketani, S., Nakayama, K., Sugita, Y., and Bannai, S. (1993) J. Biol. Chem. 268, 18633-18636]. Thioredoxin peroxidase as well as HBP23 and the mouse macrophage 23-kDa stress protein are members of the peroxiredoxin family, a recently recognized class of antioxidant proteins [Chae, H. Z., Chung, S. J., & Rhee, S. G. (1994) J. Biol. Chem. 269, 27670-27678]. An increase in HBP23 mRNA was observed in Hepa 1-6 cells after treatment with heme and cadmium and during liver regeneration after partial hepatectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1994

The rat and human hemopexin genes contain an identical interleukin-6 response element that is not a target of CAAT enhancer-binding protein isoforms.

Hemopexin (Hx) is an abundant acute-phase protein (APP) that binds heme with high affinity. In rat hepatic cells, the transcription rate of the Hx gene is increased by interleukin (IL)-1 and IL-6. To investigate the cis-acting regulatory elements (REs) responsive to these hormones, chloramphenicol acetyltransferase constructs of rat and human Hx gene sequences were tested in transiently transfected hepatoma cells. An IL-6-RE was identified in the promoter of both rat and human Hx genes, the function of which was dependent on the core sequence (CCGGGAA) common in other APP genes. The previously characterized Hx A element mediated a relatively minor cytokine response as compared with the Hx IL-6-RE. The human Hx A element, in contrast to the rat and human Hx IL-6-REs, was strongly trans-activated by cotransfected CAAT enhancer-binding proteins (C/EBP)-beta and -delta. The rat gene homolog of the human Hx A element was inactive as a cytokine RE and was minimally trans-activated by C/EBP isoforms. Results of electrophoretic mobility shift assays indicated that the Hx IL-6-RE is a binding site for the IL-6-inducible nuclear protein IL-6 RE-BP, which also binds to the conserved IL-6-REs of other APP genes and is distinct from C/EBP beta.

Animals↗
PubMed1994

Identification of a liver preference enhancer element of the rat hemopexin gene and its interaction with nuclear factors.

Transcription of hemopexin (Hx) occurs predominantly in the liver. To investigate the contribution of the cis-acting enhancer element to the hepatocyte preferential expression, we performed chloramphenicol acetyl-transferase (CAT) assays in HepG2 cells. A strong enhancer element was identified by successive truncation to reside in the region -157/-104 from the cap site. The Hx region -145/-125 interacts with rat liver nuclear proteins, as shown by standard DNA-protein binding assays. The nucleotide sequence -141AGACTTTGACCT-130 includes, in reverse orientation, a direct repeat of the imperfect AGGTCA sequence, one of the recognition motifs of the steroid-thyroid hormone receptor superfamily. That this AGGTCA repeat is an enhancer core of the Hx element was affirmed by mutational analyses. In electrophoretic mobility shift assays, oligonucleotides, corresponding to binding regions of chicken ovalbumin upstream promoter transcription factor (COUP-TF) and apolipoprotein AI regulatory protein 1 (ARP-1) but not of hepatocyte nuclear factor-4 (HNF-4), competed with the Hx element for binding sites. Co-transfection analyses indicated that HNF-4 does not affect CAT expression whereas ARP-1 and COUP-TF repress it. Antibody supershift analyses suggested that HNF-4 and COUP-TF may not be major factors binding to the Hx element.

Animals↗
PubMed1993

Cardiodynamic and neurohormonal importance of atrial contribution in rate-responsive pacing.

To elucidate the physiologic importance of atrial contribution in recently developed rate-responsive pacing, changes in cardiodynamics and neurohormonal factors were analyzed during exercise in patients with respiratory rate-dependent, rate-responsive atrial (AAIR; n = 6) and ventricular (VVIR; n = 9) demand mode pacemakers implanted for sick sinus syndrome. With increasing pacing rate during bicycle ergometer exercise, the AAIR group had significant increases in cardiac index (p < 0.05), left ventricular ejection fraction (p < 0.05), and ejection (p < 0.05) and peak filling (p < 0.05) rates; however, the VVIR group had a significant decrease in ejection fraction (p < 0.05), and an increase in cardiac index (p < 0.05) that was significantly less than in the AAIR group. At rest, the mean plasma concentrations of atrial natriuretic peptide (p < 0.005) and cyclic guanosine monophosphate (p < 0.05) were significantly greater in the VVIR group than in the AAIR group and normal subjects (n = 8). Atrial natriuretic peptide, norepinephrine, and cyclic adenosine and guanosine monophosphates were significantly greater (p < 0.05) during exercise, and atrial natriuretic peptide was significantly greater in the VVIR group (207.5 +/- 8.3 pg/ml) than in the AAIR group (116.4 +/- 51.5) and normal subjects (30.8 +/- 19.2; p < 0.05); this suggested a further increase in the nonphysiologic atrial overload with VVIR pacing. The data show both the neurohormonal and cardiodynamic importance of atrioventricular synchrony in rate-responsive pacing.

Aged↗
PubMed1993

Micronucleus test and erythropoiesis: effect of cobalt on the induction of micronuclei by mutagens.

The micronucleus test is used widely as an in vivo short-term assay for potential carcinogens. In the present study, results of the micronucleus test were affected by cobalt dichloride pretreatment. Cobalt dichloride was used to induce erythropoietin, a growth factor for erythropoiesis. The increase in mutagen-induced micronucleus response following cobalt pretreatment, therefore, may have been due to a change in the rate of erythropoiesis. The greatest interaction between cobalt pretreatment and mutagen treatment for the induction of micronucleated polychromatic erythrocytes (MPCE) occurred when mice were injected with 1,1-dimethylhydrazine (DMH) 12-24 hr after pretreatment with cobalt dichloride and killed 30 hr later. Increased sensitivity of the micronucleus test was attributable to the administration of mutagen during the differentiation and multiplication of erythroblast, which is presumed to have been accelerated by pretreatment with cobalt dichloride. An increased induction of MPCE in the bone marrow by two chemicals--benzo(a)pyrene, 2-naphthylamine--was also observed following pretreatment with cobalt dichloride.

2-Naphthylamine↗
PubMed1992

Identification of an interleukin-6 responsive element and characterization of the proximal promoter region of the rat hemopexin gene.

The rat hemopexin (Hx) gene was isolated and studies of its transcriptional regulation initiated. For analysis by a transient expression assay, the sequence between -2400 and +21 and sequential 5' truncates were linked to the chloramphenicol acetyltransferase (CAT) gene. HepG2 cells transfected with these CAT constructs were treated with conditioned medium of lipopolysaccharide stimulated human monocytes, interleukin-1 (IL-1) or interleukin-6 (IL-6). The activities of putative regulatory regions joined to the SV40 promoter indicated that the flanking region of the rat Hx gene from -209 to -104 contains three functional regions designated proximal regulatory regions; PRR-I (-209 to -173), -II (-178 to -158) and -III (-154 to -104). We found that PRR-II contains a different class of IL-6 responsive element (RE) from that reported for the human Hx gene, and that PRR-I and PRR-III participate in the basal expression of rat Hx in HepG2 cells.

Acute-Phase Reaction↗
PubMed1992

Effect of estrogen on liver plasma membrane in rats.

The effect of estrogen on plasma membrane was investigated using the primary cultured rat hepatocytes treated with carbon tetrachloride (CCl4) and the isolated plasma membrane of rat liver. 17 beta-Estradiol (E2), at concentrations of 10(-10) M to 10(-4) M, 10(-8) M to 10(-6) M and 10(-12) M to 10(-4) M, had an inhibitory effect on the CCl4-induced leakage of glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and lactate dehydrogenase, respectively from primary cultured rat hepatocytes. Diethylstilbestrol, which caused inhibition at a dose of 10(-4) M, did not inhibit any enzyme leakage at any further concentrations of 10(-12) M to 10(-6) M. In the isolated plasma membrane of rat liver, Mg(2+)- and Na+,K(+)-adenosine triphosphatase activity was increased by E2 treatment at concentrations of 10(-6) M and 10(-4) M.

Alanine Transaminase↗
PubMed1991

Effect of estrogen on induction of micronuclei by mutagens in male mice.

The effect of estrogen on the induction of micronucleated polychromatic erythrocytes (MPCE) by mutagens was examined in male mice. In the dose-response study, a dose-related inhibition of the mitomycin C (MMC)-induced MPCE frequency by estradiol (E2) treatment was observed. In the time study, inhibitory effects of E2 on MPCE frequency by MMC were observed when MMC was administered at 0 or 1 day after injection of E2. The most effective protocol for inhibition was when E2 and MMC were used on the same day. Of mutagens other than MMC, only vincristine (VCR) showed a significant decrease in MPCE frequency when used together with E2. Benzo[a]pyrene (BaP) and 5-fluorouracil (5-FU) showed no significant decrease in MPCE frequency. The data suggest that the induction of micronuclei by mutagens is inhibited by treatment with estrogen, and this could result in a sex difference in the sensitivity of mice employed in the micronucleus test. Mechanisms of the inhibitory effects of estrogen are discussed; these might include a suppression of erythropoiesis and a possible effect on the cell membrane permeability of erythroblasts.

Animals↗