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C Sugawara

Publications and source records attributed to C Sugawara.

At least 19 recordsLinked to original sources
PubMed1998

Mapping of a novel human carbonyl reductase, CBR3, and ribosomal pseudogenes to human chromosome 21q22.2.

To find the genes contributing to Down syndrome, we constructed a 4-Mb sequence-ready map spanning chromosome 21q22.2 with megabase-sized cosmid/P1-derived artificial chromosome (PAC) contigs. The restriction map with rare cutting enzymes, followed by sequencing from the clustering sites, has defined CpG islands and revealed the genes associated with CpG islands (Accession No. D85771). Of these, two human carbonyl reductases (CBR; EC1.1.1.184) were found in a PAC 25P16 clone. CBR catalyzes the reduction of a large number of biologically and pharmacologically active carbonyl compounds to their corresponding alcohols and has been mapped in 21q22.1. To confirm these results, we sequenced the PAC clone in shotgun strategies and identified a novel carbonyl reductase, designated CBR3, 62 kb downstream from the original CBR. In addition, three ribosomal pseudogenes, L23a, S9, and L3, and some cDNAs with ESTs were mapped in the sequence. In conclusion, the sequence analysis for CpG islands predicted from the megabase-sized contigs will reveal and identify the genes involved in Down syndrome.

Alcohol Oxidoreductases↗
PubMed1998

Nucleotide sequencing analysis of the 146-kilobase segment around the IkBL and MICA genes at the centromeric end of the HLA class I region.

To elucidate the complete gene structure and to identify new genes involved in the development of HLA class I antigen-associated diseases in the class I region of the human major histocompatibility complex on chromosome 6, a YAC clone (745D12) covering the 146-kb segment around the IkBL and MICA loci was isolated from a YAC library constructed from the B-cell line, BOLETH. A physical map of this region was constructed by isolation of overlapping cosmid clones derived from 745D12. Of these, five contiguous cosmids were chosen for DNA sequencing by the shotgun strategy to give a single contig of 146,601 bp from 2.8 kb telomeric of the IkBL gene to exon 6 of MICA. This region was confirmed to contain five known genes, IkBL, BAT1, MICB, P5-1, and HLA-X (class I fragment), from centromere to telomere, and their exon-intron organizations were determined. The 3.8-1 homologue gene (3.8-1-hom) showing 99.7% identity with the 3.8-1 cDNA clone, which was originally isolated using the 3.8-kb EcoRI fragment between the HLA-54/H and the HLA-G genes, was detected between MICA and MICB and was suggested to represent the cognate 3.8-1 genomic sequence from which the cDNA clone was derived. No evidence for the presence of expressed new genes could be obtained in this region by homology and EST searches or coding and exon prediction analyses. One TA microsatellite repeat spanning 2545 bases with as many as 913 repetitions was found on the centromeric side of the MICA gene and was indicated to be a potential hot spot for genetic recombination. The two segments of approximately 35 kb upstream of the MICA and MICB genes showed high sequence homology (about 85%) to each other, suggesting that segmental genome duplication including the MICA and MICB genes must have occurred during the evolution of the human MHC.

Carrier Proteins↗
PubMed1997

Nucleotide sequence analysis of the HLA class I region spanning the 237-kb segment around the HLA-B and -C genes.

To elucidate the detailed gene organization of the human leukocyte antigen (HLA) class I region on chromosome 6, seven contiguous cosmid genomic clones covering the 237-kb segment around the HLA-B and -C loci were subjected to DNA sequencing by the shotgun strategy to give a single contig of 236,822 bp from the MICA gene (58.2 kb centromeric of HLA-B) to 90.8 kb telomeric of HLA-C. This region was confirmed to contain four known genes, MICA, HLA-17, HLA-B, and HLA-C, from centromere to telomere. Further, a new member of the P5 multicopy genes was found to be about 1.3 kb upstream of the HLA-17 gene and designated P5.8. Five novel genes designated NOB1-5 were identified by RT-PCR and Northern blot hybridization. In addition, two pseudogenes, dihydrofolate reductase pseudogene (DHFRP) and ribosomal protein L3 homologous gene (RPL3-Hom), were also found in the vicinity of the HLA-B and -C genes, respectively. The two segments (about 40 kb) downstream of the HLA-B and HLA-C genes showed high sequence homology to each other, suggesting that segmental genome duplication including the major histocompatibility complex (MHC) class I gene must have occurred during the evolution of the MHC.

Blotting, Northern↗
PubMed1996

Accumulation of orally given cadmium in Long-Evans Cinnamon (LEC) rats with an inherently abnormal copper metabolism.

An inherent defect of biliary Cu excretion and subsequent Cu deposition in the liver have been found in Long-Evans Cinnamon (LEC) rats, which are promising models of Wilson disease. LEC and Fischer rats were given water containing Cd (CdCl2) at a level of 5 ppm for 30 days. Regardless of drinking Cd water, LEC rats showed a very high concentration of Cu (200 to 250 microgram/g) and Cu-metallothionein (Cu-MT) (18 mg/g) in the liver. There was no difference of Cd accumulation in the liver between the two strains exposed to Cd (2.6 and 2.7 microgram/g in the Fischer and LEC groups, respectively). However, the renal Cd concentration was slightly but significantly higher in LEC rats (3.5 microgram/g) than in Fischer rats (2.0 microgram/g). The ratio of renal Cd contents to the sum of renal and hepatic Cd contents was significantly higher in LEC rats (0.25) than in Fischer rats (0.15). The serum Cd concentration in Cd-treated LEC rats increased threefold compared to Cd-treated Fischer rats. It seems likely that Cd from the liver is transported into the kidney in the form of Cd, Cu-MT. There was no difference in uptake of Cd in the hepatic MT fraction between the two strains. Although biliary Cu excretion in LEC rats was significantly lower than that in Fischer rats, reduced excretion of Cd into bile was not found in LEC rats. The gross amounts of Cu and Cu-MT influenced the accumulation of Cd in the kidney rather than in the liver when Cd was given orally at a low level to LEC rats. Our results suggest tht Cu and Cd do not share the same sites of hepatobiliary excretion in rats, although the main route of their excretion is via bile.

Administration, Oral↗
PubMed1996

Antigenicity of cell wall mannans of Candida albicans NIH B-792 (serotype B) strain cells cultured at high temperature in yeast extract-containing sabouraud liquid medium.

Cultivation of Candida albicans NIH B-792 (serotype B) at high temperature (37 degrees C) for 48 h in yeast extract-containing Sabouraud liquid medium (YSLM) provided the following findings in comparison with the findings obtained after incubation at 27 degrees C. Growth of the blastoconidia of this strain was decreased, with a dry weight of 9%, and the cells were deficient in cytokinesis. The cells did not undergo agglutination with serum factor 5 from a commercially available serum factor kit (Candida Check). Mannan (B-37-M) obtained from the cells cultured at 37 degrees C had partially lost its reactivity against serum factor 4 and lost most of its reactivity against serum factor 5 in an enzyme-linked immunosorbent assay (ELISA) in contrast to that (B-27-M) at 27 degrees C. Both cells and mannan prepared by cultivation first at 37 degrees C and then at 27 degrees C entirely recovered their reactivities with serum factors 4 and 5. 1H-nuclear magnetic resonance analysis also revealed that B-37-M had lost a beta-1,2-linked mannopyranose unit and retained a phosphate group. Similar changes were observed in the three other serotype B strains used in the study. The beta-1,2-linked mannooligosaccharides longer than mannotetraose were not included among the products released from B-37-M by mild acid treatment. The results of the inhibition ELISA with a series of beta-1,2-linked mannooligosaccharides from biose to octaose (M2 to M8, respectively) showed that the reactivity against serum factor 4 was inhibited most strongly by the oligosaccharides M4 to M8 and that the reactivity against serum factor 5 was inhibited completely by relatively longer oligosaccharides, M5 to M8, indicating their participation as the antigenic factor 5 epitopes.

Agglutination Tests↗
PubMed1995

Biliary excretion of copper, metallothionein, and glutathione into Long-Evans Cinnamon rats: a convincing animal model for Wilson disease.

Long-Evans Cinnamon (LEC) rats, characterized by a gross accumulation of hepatic Cu and the spontaneous onset of hepatitis, have been established to be an animal model for Wilson disease. They were used to estimate the relationships among copper (Cu), metallothionein (MT), and reduced glutathione (GSH) in biliary excretion in this study. Even though a huge amount of MT existed in the LEC rat liver (5016 micrograms/g liver) compared to that (63 micrograms/g liver) of controls (Fischer rats), the biliary excretion of MT (65 ng/ml bile) did not reflect the accumulated MT level in LEC rats. It seems likely that MT does not excrete intrinsically into the bile. Biliary excretion of Cu (0.17 microgram/ml) in LEC rats was significantly lower than that (0.57 microgram/ml) in Fischer rats. The difference in biliary excretion of GSH between the two groups was significant but slight. The reduced excretion of GSH into bile in LEC rats may be due to increased hepatic gamma-glutamyltransferase but not to hepatic GSH levels. There were no differences in biliary potassium and inorganic phosphorous between the two groups. On the other hand, excretion of lysosomal enzymes such as beta-N-acetylglucosaminidase into bile was much lower in LEC rats (15.6 units/liter) than in controls (42.5 units/liter). The defective biliary excretion of Cu may be due to impaired lysosomal exocytosis, rather than canalicular membrane impairment. The LEC rat is very useful for research into the dynamics of metal excretion via the hepatobiliary system.

Acetylglucosaminidase↗
PubMed1994

Biliary excretion of exogenous cadmium and manganese in Long-Evans Cinnamon (LEC) rats characterized by an inherently gross amount of copper-metallothionein in the liver.

Long-Evans Cinnamon (LEC) rats are characterized by the sudden onset of hepatitis around 4 months after birth and the gross accumulation of hepatic copper (Cu) accompanied by metallothionein (MT). The biliary excretion of manganese (Mn) and cadmium (Cd) injected intravenously was studied in 3-month-old LEC rats without signs of hepatitis. Injected Mn was excreted into the bile in LEC and Fischer rats used for comparison. However, increased biliary excretion of Cd was found not in the LEC rat but in the Fischer rat. Excretion of horseradish peroxidase (HRP) injected along with the metal mixture was significantly lower in the LEC group than in the Fischer group. Our results suggest that Mn excretion is not related to the existence of a gross amount of Cu-MT. Reduced excretion of Cd may be partly due to binding to Cu-MT in the liver. Decreased excretion of HRP implies the existence of an inherent defect in the bile excretion route for endo- and exogenous substances.

Animals↗
PubMed1994

A copper deficient diet prevents hepatic copper accumulation and dysfunction in Long-Evans Cinnamon (LEC) rats with an abnormal copper metabolism and hereditary hepatitis.

Long-Evans Cinnamon (LEC) rats that develop spontaneous hepatitis due to an inherently abnormal Cu metabolism have recently been established. This investigation concerns the effects of a Cu-deficient diet on the Cu metabolism linked to hepatic injury in LEC rats. The hepatic Cu concentration at 30 days after birth was 94 +/- 4 Cu micrograms/g liver in LEC rats, whereas that of Fischer rats at the same age was 7 +/- 1 Cu micrograms/g. From 30 days after birth, all rats were fed a semisynthetic diet with two different levels of Cu, 0.5 or 30 micrograms/g food, for 35 days. In LEC rats fed a Cu-deficient diet (0.5 microgram/g), the hepatic Cu concentration was 39 +/- 7 micrograms/g. The Cu-normal diet (30 micrograms/g) LEC group had a concentration of 357 +/- 15 micrograms/g in the hepatic Cu. The group had significantly higher aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT) and gamma-glutamyl transferase (GGT) levels than did the LEC rats given the Cu-deficient diet. These results suggest that the occurrence of acute hepatitis in LEC rats can be prevented by feeding the animals a Cu-deficient diet.

Animals↗
PubMed1994

Removal of copper from the liver of Long-Evans Cinnamon (LEC) rats by tetrathiomolybdate (TTM) injection: the main excretion route is via blood, not bile.

Tetrathiomolybdate (TTM) was injected at a dose of 10 mg/kg bw daily for eight consecutive days into Long-Evans Cinnamon (LEC) rats, which inherently abnormally deposit Cu (260 micrograms/g) in the liver. The hepatic Cu (100 micrograms/g) and metallothionein (MT) bound Cu (from 2,600 to 540 micrograms/g protein) concentrations were decreased greatly by the injection. On the other hand, the renal Cu concentration increased significantly, but the brain Cu concentration only very slightly. The reduction of the hepatic Cu concentration was accompanied by reductions of Zn and Fe concentrations in the liver, kidney and brain. The TTM compound slightly stimulated excretion (about 3-fold) of Cu into the bile, but greatly (about 40-fold) into the blood. In rats not treated with TTM, most biliary (100%) and serum (78%) Cu was recovered in the trichloroacetic acid (TCA) soluble fraction. On the other hand, in rats treated with TTM, bile and serum Cu were recovered overwhelmingly in the TCA insoluble fraction, probably in the form of a Cu-TTM-albumin complex. Our results suggest that although there is an inherent failure in the intrinsic secretory process of Cu from the liver in LEC rats, the TTM compound can remove Cu from Cu-MT, resulting in a decrease of hepatic Cu.

Animals↗
PubMed1994

Role of hepatic copper-metallothionein on liver function of Long-Evans cinnamon rats with a new mutation causing hereditary hepatitis.

Liver slices from Wistar and Long-Evans Cinnamon (LEC) rats were incubated while open to the atmosphere to assess the liver function in LEC rats. Leakages of glutamic-oxaloacetic transaminase (GOT) and lactic dehydrogenase (LDH) into the medium were significantly lower in the LEC rat than in the Wistar rat. Furthermore, no pronounced enhancement of the concentration of thiobarbituric acid-reactive substances (TBARS) was found in the LEC rat. Hepatic Cu and Cu-metallothionein (Cu-MT) concentrations were 355.0 +/- 18.7 micrograms/g liver and 2559 +/- 181 micrograms/g protein in the LEC rats, whereas Wistar rats showed 4.1 +/- 0.1 Cu microgram/g liver accompanied by 16 +/- 4 micrograms/g protein of MT. The decrease of intrahepatic Cu-MT in LEC rats was stimulated by incubation with Fenitrilotriacetate (Fe-NTA). There was a direct correlation between the enhancement of TBARS and disappearance of Cu-MT. Our results suggest that hepatic Cu-MT in LEC rats protects against liver injury stimulated by oxidative stress.

Animals↗
PubMed1993

Decrease in biliary excretion of copper in Long-Evans cinnamon (LEC) rats causing spontaneous hepatitis due to a gross accumulation of hepatic copper.

The concentration of biliary Cu was 0.12 +/- 0.01 microgram/ml in male LEC rats aged 14 weeks and 0.43 +/- 0.09 micrograms/ml in Fischer rats of the same age. When copper chloride (170 micrograms/kg b.w. as Cu) was infused intravenously (i.v.), the concentration of biliary Cu increased to only 0.21 +/- 0.06 microgram/ml 30 min after the infusion in LEC rats. In contrast, Fischer rats showed a concentration about 10 times higher (4.02 +/- 2.2 micrograms/ml) than that before the infusion. In Fischer rats pretreated with cadmium chloride, the biliary Cu concentration was 1.04 + 0.43 micrograms/ml 30 min after infusion of copper. Horseradish peroxidase (E.C.1.11.1.7) infused iv along with copper chloride was excreted into bile at a low level in LEC rats compared to Fischer rats. Our results suggest that the gross accumulation of hepatic Cu in the new, mutant LEC rats is due to a low excretion of Cu into bile and that the hepatobiliary dysfunction is related to spontaneous hepatitis.

Animals↗
PubMed1992

Regional distribution of copper, zinc and iron in the brain in Long-Evans Cinnamon (LEC) rats with a new mutation causing hereditary hepatitis.

In Long-Evans Cinnamon (LEC) rats of three different ages (7, 13 and 32 weeks old) concentrations of Cu, Zn and Fe were measured in 8 regions of the brain. The LEC groups aged 7 and 13 weeks showed low concentrations of Cu in all regions compared to Long-Evans Agouti (LEA) rats. In 32-week-old LEC rats, however, Cu concentrations increased in 7 regions, in particular, significantly so in the striatum, hypothalamus, cerebellum, midbrain and cortex. Changes of Zn concentration were not found in any region. The Fe concentration increased in cortex and olfactory lobes. The three LEC groups showed a very high concentration of hepatic Cu and a low concentration of serum Cu compared to LEA rats. In LEC rats aged 32 weeks, however, hepatic Cu decreased and serum Cu increased compared to the other two LEC groups. These results suggest that the increase of the cerebral Cu concentration is closely related to the inherently abnormal Cu metabolism and then to the changes of Cu metabolism from about 13 weeks after birth.

Animals↗
PubMed1992

The effects of aluminum ingestion on intestinal cadmium absorption, lipid peroxidation and alkaline phosphatase activity.

Consumption of dietary aluminum (A1, 2000 or 4000 ppm) for 1 month did not influence mouse body weight. In order to estimate an absorption of cadmium (Cd) from the gastrointestinal tract, mice were intubated twice every 24 h with Cd (CdCl2). In the A1-supplemented mice, Cd absorption increased rather than decreased. Intestinal Cd and metallothionein concentrations were increased by the A1 supplement. Intestinal alkaline phosphatase activity and lipoperoxide concentrations were also enhanced by A1 ingestion. Of course, intestinal A1 concentration was at a high level in the A1-supplemented groups. However, A1 accumulation was not observed in the liver. The increase of Cd absorption may be due to an abnormality of the gut wall caused by the A1. Our results suggest that A1 is not inert for animals, even though A1 absorption is poor.

Administration, Oral↗
PubMed1992

Excessive accumulation of hepatic copper in LEC rats aged 80 days without hepatitis and 130 days with hepatitis.

The Cu concentration was about 40 and 60 times higher in the liver in Long-Evans with a cinnamon-like coat color (LEC) rats aged 80 days (without hepatitis) and 130 days (with hepatitis), respectively than in the liver in Fischer rats. Most hepatic Cu was recovered in the cytosol fraction. Furthermore, about 96% and 84% of the cytosolic Cu was found in the metallothionein region on a Sephadex G-75 column in LEC rats aged 80 and 130 days, respectively. The hepatic metallothionein concentration was about 130 to 140 times higher in LEC rats than in Fischer rats when the concentration was expressed as metallothionein-bound Cu. Three forms of Cu-metallothionein were isolated by DEAE-cartridge. Although the concentration of hepatic Cu-metallothionein and its composition of polymorphic form were not changed greatly in hepatitis phase (in the 130-day-old LEC rats), activities of serum enzymes, aspartate aminotransferase (GOT) and alanine aminotransferase (GPT) were increased significantly. The LEC rat showed a significantly low concentration of biliary Cu and markedly low activity of ceruloplasmin (as ferroxidase). Serum Cu showed a low concentration in the 80-day-old LEC rats, but recovered to the control level in the 130-day-old LEC rats. The abnormal accumulation of Cu may be due to the inherent reduction of excretion of Cu into the bile and blood. Such deposition may be a trigger for the onset of the spontaneous hepatitis occurring at 90-120 days after birth and for the onset of hepatoma later.

Animals↗
PubMed1992

Copper metabolism in new mutant Long-Evans cinnamon (LEC) rats causing hereditary hepatitis: gastrointestinal absorption and distribution of radioisotopic copper (64Cu).

Long-Evans cinnamon (LEC) rats 60 days old showed a concentration of 127.7 +/- 10.9 micrograms/g of Cu in the liver, compared to 1.6 +/- 0.1 micrograms/g in Fischer rats 60 days old. At 2 hr after an oral injection of 64Cu, total retention of 64Cu in the whole blood, liver and kidneys was 16.8 +/- 3.4% of the dose in LEC rats, compared to 13.1 +/- 1.3% in Fischer rats. The recovery rates of retained-64Cu in the livers in LEC and Fischer rats were 82% and 59%, respectively. More than 90% and about 60% of hepatic 64Cu existed in the cytosol fraction in LEC and Fischer rats, respectively. Furthermore, more than 90% of the cytosolic 64Cu was found as MT in LEC rats. In Fischer rats, this proportion was about 60%. In the duodenum mucosal cytosol fraction from LEC rats, about 50% of 64Cu was bound to metallothionein (MT) protein. In Fischer rats, this proportion was less than 20%. When a 64Cu compound was intraperitoneally injected, 70% and only 15% were recovered in the liver 20 hr after the injection in LEC and Fischer rats, respectively. Furthermore, LEC rats showed very low 64Cu activity in the serum, and their duodenal activities were slightly low compared to Fischer rats. These results suggest that the gross accumulation of hepatic Cu is mainly due to deficient excretion of Cu from the liver.

Animals↗
PubMed1991

Copper metabolism in the LEC rat: involvement of induction of metallothionein and disposition of zinc and iron.

The Cu concentration was about 40 times higher in the liver of LEC (Long-Evans with a cinnamon-like coat color) rats aged 77 days (227.5 +/- 21.6 micrograms/g liver) than in Fischer rats (5.2 +/- 0.1 microgram/g liver). However, in the kidney and brain of the LEC rats, Cu concentrations were lower than in these organs of the Fischer rats. Cu concentration in the hepatic metallothionein fraction was about 130 times higher in the LEC rats than in the Fischer rats. The LEC rats showed markedly low concentrations of Cu in the serum and bile. It seems likely that excretion of Cu from the liver into the bile and blood (as ceruloplasmin) is inherently lacking in the LEC rat.

Animals↗
PubMed1991

Gastrointestinal absorption of Cd-metallothionein and cadmium chloride in mice.

CdCl2 or Cd-metallothionein (MT) (6 micrograms Cd with 2.25 muCi (83.25 KBq) 109Cd) was given orally to mice, which were sacrificed at 30 min and 2 h after intubation. Although 109Cd in Cd-MT was excreted rapidly into the urine, its absorption was found to be significantly less than that of CdCl2. The poor absorption was due to a decrease of Cd-MT uptake into the intestine. Cadmium chloride taken up into the mucosa could stimulate MT synthesis even 30 min after its intubation. However, the percentage of MT-bound Cd in the Cd of intestinal supernatants was lower with CdCl2 (62% at 30 min and 2 h) than with Cd-MT (78% and 84% at 30 min and 2 h, respectively). These results suggest that the transport mode of lumenal Cd-MT to mucosal cells is different from that of lumenal CdCl2. Lumenal Cd-MT is probably internalized into intestinal cells in an intact form. Furthermore, the Cd-MT may pass through the basolateral membrane in this form. This hypothesis was supported by the different distributions of Cd in the liver and kidney after Cd-MT and CdCl2 intubations.

Animals↗