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Biomedical subjects

R Konno

Publications and source records attributed to R Konno.

At least 73 records · Page 4Linked to original sources
PubMed1991

Presence of D-amino-acid oxidase protein in mutant mice lacking D-amino-acid oxidase activity.

1. Mutant mice lacking D-amino-acid oxidase activity were examined as to whether they possessed the enzyme protein. 2. Immunoblotting using an antibody against hog kidney D-amino-acid oxidase showed that kidney homogenates of the mutant mice as well as that of the normal mice had proteins reactive to the antibody. 3. Peroxisomal proteins of the kidney cells of the mutant mice were not different from those of the normal mice. 4. The peroxisomes of the mutant mice possessed a protein reactive to the antibody in the immunoblotting whose size was the same as the D-amino-acid oxidase protein present in the peroxisomes of the normal mice. 5. These results suggest that the mutant mice synthesize the D-amino-acid oxidase protein and integrate it into peroxisomes, though it is a nonfunctional enzyme.

Animals↗
PubMed1990

Intestinal bacterial origin of D-alanine in urine of mutant mice lacking D-amino-acid oxidase.

Urine from mutant mice which lack D-amino-acid oxidase contained a large amount of D-alanine. The alanine content was not changed by changes in the dietary composition or by starvation. However, oral administration of an antibiotic, amoxicillin, decreased the urinary alanine to the normal level. These results suggest that the D-alanine is not of dietary origin but of intestinal bacterial origin.

Alanine↗
PubMed1990

D-aspartate oxidase activity and D-aspartate content in a mutant mouse strain lacking D-amino acid oxidase.

A mutant mouse strain ddY/DAO- lacks D-amino acid oxidase activity and accumulates free neutral D-amino acids in its tissues. In this study, D-aspartate oxidase activity and D-aspartate content in the tissues of these mutant mice were compared with those of normal mice. No significant difference was observed, indicating that the metabolism of acidic D-amino acids was unaffected in the mutant.

Amino Acid Oxidoreductases↗
PubMed1990

Detection of human papillomavirus (HPV) type 16 and 52b in cervical cancer tissues by Southern blot hybridization and polymerase chain reaction (PCR).

DNA samples from cancer tissues diagnosed histologically as squamous cell carcinoma of the uterine cervix were examined for the presence of human papillomavirus (HPV) genome DNA by Southern blot hybridization. Of 63 specimens, 32 were found to hybridize with HPV DNA probes; 23 specimens (35%) with HPV type 16 (HPV16), one (2%) with HPV type 18 (HPV18), four (7%) with HPV type 52b (HPV52b), and four others (7%) weakly with HPV52b. Specimens negative for HPV DNA with Southern blot hybridization were subjected to polymerase chain reaction (PCR) to determine the presence of HPV DNA under more sensitive conditions. After PCR using one set of primers specific for HPV16 and HPV52b, 7 out of 31 specimens were found to have HPV16 DNA. None was positive for HPV52b DNA. Our results indicate that HPV52b, as well as HPV16 and HPV18, is associated with squamous cell carcinoma of uterine cervix, and more sensitive determination of HPV infection can be made by amplification of the viral genome by PCR.

Base Sequence↗
PubMed1990

Detection of human papillomavirus DNA in genital condylomata in women and their male partners by using in situ hybridization with digoxygenin labeled probes.

Twelve couples (12 women and their male partners) presenting genital warts were investigated in order to evaluate the sexual transmission of human papillomavirus (HPV) in mutual partners and the localization of HPV DNA. Formalin-fixed, paraffin-embedded biopsy samples of 12 vulvar condylomata, and 12 penile condylomata from male partners were analyzed for the presence of HPV DNA-6, -11, and 16/18 by using in situ hybridization with digoxygenin labeled DNA probes. HPV DNA was identified in 9 women (75%) and in 9 men (75%). HPV-6 was frequently identified, being revealed in 42% of the vulvar specimens, in 67% of the cervical specimens and 58% of the penile specimens. Seven of 9 (77%) positive couples shared the same HPV DNA, and 2 couples harbored different HPV DNA types between the partners. The signal intensity of the HPV DNA was generally strong in superficial cell layers, weak in parabasal or basal cell layers. No malignant lesions resulted from the condyloma acuminatum caused by HPV-6 or -11. There were only mild dysplasia in the both sexes.

Condylomata Acuminata↗
PubMed1989

Spontaneous excretion of D-alanine in urine in mutant mice lacking D-amino-acid oxidase.

Urine from mutant mice lacking D-amino-acid oxidase contained a large amount of alanine compared with that from normal mice. Urinary alanine of the mutant mice was sensitive to D-amino-acid oxidase. H.p.l.c. showed that about 94% of the urinary alanine had the D-configuration. These results suggest that D-amino-acid oxidase functions to decompose D-amino acid(s) in normal mice.

Alanine↗
PubMed1989

Involvement of D-amino acid oxidase in elimination of free D-amino acids in mice.

The physiological role of D-amino acid oxidase was investigated by using mutant ddY/DAO- mice lacking the enzyme. Free D-amino acid concentrations in the mutant mice were significantly higher than those of control ddY/DAO+ mice in kidney, liver, lung, heart, brain, erythrocytes, serum and urine. The results suggest that the enzyme is involved in the catabolism of free D-amino acids in the body, and that free D-amino acids are also excreted into urine.

Amino Acids↗
PubMed1989

Linkage of the Dao-1 gene for D-amino-acid oxidase to the pgm-1 gene for phosphoglucomutase-1 on the mouse chromosome 5.

Linkage of the Dao-1 gene controlling D-amino-acid oxidase to the Pgm-1 gene controlling phosphoglucomutase-1 on the mouse chromosome 5 was examined. Mutant ddY/DAO- mice carrying a null Dao-1c allele had a Pgm-1a allele. Mutant mice were crossed to C3H/HeN and NZB/Kl mice carrying the Dao-1+ and Pgm-1b alleles. The hybrid F1 mice were backcrossed to the ddY/DAO- and their progeny were examined for alleles for D-amino-acid oxidase and phosphoglucomutase-1. In both backcrosses, the progeny with recombinant-type combinations of the alleles were significantly less than the progeny with the parental-type combinations, indicating the linkage of the Dao-1 and Pgm-1 genes. The recombination frequency between these loci was estimated to be 19.8 +/- 4.0%.

Alleles↗
PubMed1989

Detection of human papillomavirus type 52b in cervical dysplastic tissue.

We examined infection in the tissue of cervical dysplasia of human papillomavirus (HPV) 52b, which we recently isolated from cervical cancer. To screen a lot of samples, we used an assay system with an HPV DNA typing kit containing an HPV 33 probe that cross-hybridizes with HPV 52b DNA. DNA samples from 123 patients with cervical dysplasia were first screened with this kit. Sixteen of these appeared to be positive, and they were subjected to Southern blot hybridization with the HPV 52b probe under highly stringent conditions. Of the 16 samples, two were found to have HPV 52b genome DNA. Our results, together with the fact that HPV 52b was isolated from cervical cancer, seem to support the notion that HPV 52b infection is closely associated with the onset of cervical cancer.

Blotting, Southern↗
PubMed1989

[Human papillomavirus DNA in vulvar lesions].

In order to study the role of human papillomavirus (HPV) in genital cancer, we attempt to determine the presence of HPV in tumors of the genital tract. In the current study, we have examined 35 histologically diagnosed cases of vulvar lesions in attempts to compare the sensitivities of various methods of detecting HPV. All but 7 vulvar lesions contained HPV DNA by Southern blot DNA hybridization. Detectability of HPV by immunocytochemistry and koilocytosis significantly declined as compared to DNA hybridization. The detection of HPV DNA by in situ hybridization is discussed.

Blotting, Southern↗
PubMed1988

Lack of D-amino-acid oxidase activity causes a specific renal aminoaciduria in the mouse.

Thin-layer chromatography and amino acid analysis showed that urine of mutant ddY/DAO- mice lacking D-amino-acid oxidase activity contained more serine, proline, alanine and methionine than that of normal ddY/DAO+ mice. Among these four, an increase in alanine was conspicuous. However, the urinary levels of 11 other amino acids and glucose were not different between the ddY/DAO- and ddY/DAO+ mice. Amino acid analysis showed that the plasma levels of serine, proline and methionine were not elevated in the ddY/DAO- mice, though a slight increase in alanine was observed. Genetic crosses showed that aminoaciduria and lack of D-amino-acid oxidase activity were concomitantly transmitted as a set through generations. These results indicated that the lack of enzyme activity caused a specific renal aminoaciduria. Whether this enzyme merely diminishes the D-amino acid load presented for reabsorption, or actually participates catalytically in the reabsorption process, remains undetermined.

Amino Acids↗
PubMed1988

Excessive urinary excretion of methionine in mutant mice lacking D-amino-acid oxidase activity.

Thin-layer chromatography and amino acid analysis showed that mutant (ddY/DAO-) mice lacking D-amino-acid oxidase activity excreted about 3.5 times more methionine in urine than did normal (ddY/DAO+) mice. High-performance liquid chromatography using a chiral column showed that approximately 82% of urinary methionine of the ddY/DAO- mice had the D-configuration. Analysis revealed that the mouse diet used contained 0.04% free methionine and that approximately 46% of methionine was the D-isomer. When the ddY/DAO- mice were given a diet containing a low level of supplementary DL-methionine or a diet without D-methionine, they excreted the normal levels of methionine. These results indicate that the ddY/DAO- mice were unable to metabolize D-methionine and excrete it in urine.

Amino Acids↗
PubMed1988

A simple and rapid method to screen for mutant mice lacking D-amino-acid oxidase activity.

A simple and rapid method to screen for mutant mice (Mus musculus) lacking D-amino-acid oxidase activity has been devised. Mice were given water containing small amounts (0.02%) of either D-methionine or D-phenylalanine. Urinary levels of the D-amino acid were examined using thin-layer chromatography. Some mice excreted substantial amounts of the D-amino acid through the urine. None of them had detectable D-amino-acid oxidase activity.

Animals↗
PubMed1987

Heterogeneity of intercellular adhesion in rat liver cells in culture.

The intercellular homotypic adhesive properties of 14 clones derived from a nontumorigenic rat liver epithelial cell line (LEC), derived from neonatal Fischer rats, were examined and compared to those of the hepatoma H4-II-E cell line. Each clone was assayed also for the degree of chromosomal aneuploidy and the ability to grow in soft agar. Over 100-fold differences in adhesive properties were observed among the clones, but no correlation was observed between the degree of aneuploidy in the clones and intercellular adhesive properties. The parent LEC cell line and the clones derived from it were unable to grow in soft agar. The H4-II-E cells showed negligible capacity to reaggregate after dissociation into single cells and these cells readily formed colonies in soft agar. Many of the LEC clones were similar to the H4-II-E cells in their adhesive properties, which suggests that reduced cell-to-cell adhesiveness per se is not a necessary prerequisite of epithelial cells to be able to grow independent of anchorage. Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) of concanavalin A (Con A)-binding glycoproteins in the "most adhesive" clone 67 and the "least adhesive" clone 201 showed markedly elevated amounts of acidic 105 and 67-kDa glycoproteins in clone 67. Proteins with similar migration patterns in 2D-PAGE have previously been reported to participate in specific homotypic intercellular adhesion of liver cells. The Con A-binding glycoprotein pattern in H4-II-E cells was markedly different from that of LEC cells with a set of six proteins missing and nine proteins appearing new in the H4-II-E cells. It is suggested that, in addition to identifying known epithelial cell polypeptides, systematic screening of cell surface-associated glycoproteins in normal and transformed epithelial cells in vitro and in vivo may lead to identification of novel polypeptides intimately associated with the transformed phenotype.

Aneuploidy↗
PubMed1984

Involvement of D-amino-acid oxidase in D-amino acid utilization in the mouse.

Mutant ddY/DAO- mice lacking D-amino-acid oxidase were examined for their ability to utilize D-phenylalanine in place of its L-isomer. Chemically defined milk powder devoid of phenylalanine was used as a basal diet. Adult ddY/DAO- mice and normal ddY/DAO+ mice having D-amino-acid oxidase lost weight every day when fed this diet. However, they maintained their weight when fed the milk powder diet supplemented with 0.33% L-phenylalanine. Although adult ddY/DAO+ mice maintained their weight when fed the milk powder diet supplemented with 0.33% D-phenylalanine, ddY/DAO- mice lost weight while feeding on this diet, which indicated that the ddY/DAO- mice could not utilize D-phenylalanine in place of its L-isomer. Both ddY/DAO- and ddY/DAO+ mice maintained their weight when feeding on the milk powder diet enriched with 0.41% sodium phenylpyruvate, which suggested to us that the ddY/DAO- mice had the ability to invert this alpha-keto acid to L-phenylalanine. Therefore, these results indicate that D-amino-acid oxidase is indispensable for D-amino acid utilization. This is consistent with the concept that D-amino acids are oxidatively deaminated to the corresponding alpha-keto acids by D-amino-acid oxidase and that these keto intermediates are then asymmetrically reaminated to their L-amino acids.

Amino Acids↗