Search PubMed⌕ Search

Biomedical subjects

Y Oshima

Publications and source records attributed to Y Oshima.

At least 343 records · Page 19Linked to original sources
PubMed1983

Distribution of heterogeneous and homologous plasmids in Bacillus spp.

A total of 75 strains (including 5 reference strains) of Bacillus amyloliquefaciens, B. cereus, B. circulans, B. licheniformis, B. megaterium, B. pumilus, B. sphaericus, B. subtilis, and B. thuringiensis and 36 species-unidentified Bacillus strains were surveyed for plasmids by cesium chloride-ethidium bromide equilibrium centrifugation of cell lysates in a study of antibiotic resistance in host cells. Of the 111 strains, 13 (including 3 reference strains) were found to harbor plasmids, and 5 of the 13 showed antibiotic resistance. This antibiotic resistance appeared not to be due to the plasmids, however, because the trait was not cured by cultivation of cells in nutrient medium containing ethidium bromide (1 microgram/ml), sodium dodecyl sulfate (0.2 micrograms/ml), or novobiocin (1 microgram/ml), except in one strain, in which kanamycin and streptomycin resistances were cured by novobiocin. One strain of B. amyloliquefaciens, S294, was found to harbor a plasmid, pFTB14, which differed from the plasmid species of classes 1 to 6 in B. subtilis and B. amyloliquefaciens, as determined by restriction analysis and DNA contour length determination. However, in DNA-DNA hybridization on a filter after Southern blotting from an agarose gel, the pFTB14 DNA hybridized with plasmids of classes 1 to 5. Three strains of B. thuringiensis each carried at least 4 to 11 plasmid species, whereas no plasmids were detected in four strains of B. cereus, which, in relation to B. thuringiensis, is closely related taxonomically and has highly homologous DNA sequences. The plasmid DNAs prepared from species other than B. subtilis and B. amyloliquefaciens did not hybridize with that of pFTB14.

Anti-Bacterial Agents↗
PubMed1983

Corrected Version Distribution of Heterogeneous and Homologous Plasmids in Bacillus spp.

A total of 75 strains (including 5 reference strains) of Bacillus amyloliquefaciens, B. cereus, B. circulans, B. licheniformis, B. megaterium, B. pumilus, B. sphaericus, B. subtilis, and B. thuringiensis and 36 species-unidentified Bacillus strains were surveyed for plasmids by cesium chloride-ethidium bromide equilibrium centrifugation of cell lysates in a study of antibiotic resistance in host cells. Of the 111 strains, 13 (including 3 reference strains) were found to harbor plasmids, and 5 of the 13 showed antibiotic resistance. This antibiotic resistance appeared not to be due to the plasmids, however, because the trait was not cured by cultivation of cells in nutrient medium containing ethidium bromide (1 mug/ml), sodium dodecyl sulfate (0.2 mug/ml), or novobiocin (1 mug/ml), except in one strain, in which kanamycin and streptomycin resistances were cured by novobiocin. One strain of B. amyloliquefaciens, S294, was found to harbor a plasmid, pFTB14, which differed from the plasmid species of classes 1 to 6 in B. subtilis and B. amyloliquefaciens, as determined by restriction analysis and DNA contour length determination. However, in DNA-DNA hybridization on a filter after Southern blotting from an agarose gel, the pFTB14 DNA hybridized with plasmids of classes 1 to 5. Three strains of B. thuringiensis each carried at least 4 to 11 plasmid species, whereas no plasmids were detected in four strains of B. cereus, which, in relation to B. thuringiensis, is closely related taxonomically and has highly homologous DNA sequences. The plasmid DNAs prepared from species other than B. subtilis and B. amyloliquefaciens did not hybridize with that of pFTB14.

Journal Article↗
PubMed1983

Recessive mutations conferring resistance to carbon catabolite repression of galactokinase synthesis in Saccharomyces cerevisiae.

A total of 37 recessive mutations showing enhanced resistance to the glucose repression of galactokinase synthesis have been isolated by a selection procedure with a GAL81 gal7 double mutant. These mutations were grouped into three different complementation classes. One class, reg1, contains mutants arising from mutations at a site close to, but complementing, the gal3 locus. The reg1 mutant also showed resistance to the glucose repression of invertase synthesis but not to that of alpha-D-glucosidase. The two other classes were identified as arising from recessive mutations at the GAL82 locus and the GAL83 locus, respectively, at which various dominant mutations were isolated previously. When in a constitutive background due to the GAL81 or gal80 mutation, the GAL82 and GAL83 mutations did not show a mutually additive effect on the resistance to glucose repression of galactokinase synthesis, while the reg1 and GAL82 (or GAL83) mutations did. Based upon the specific behavior of cells with various genotypes for the above genes in response to the concentration of galactose and glucose in the medium, we propose a model involving three independent circuits for glucose signals in the regulation of the structural genes for the galactose pathway enzymes.

Drug Resistance, Microbial↗
PubMed1983

Cyclic AMP may not be involved in catabolite repression in Saccharomyces cerevisiae: evidence from mutants unable to synthesize it.

Yeast cells with a nonsense adenylate cyclase mutation, cyr1-3, required cyclic AMP for growth. This phenotype was suppressed by the byc1 mutation; however, cyr1-3 bcy1 cells produced no detectable level of adenylate cyclase or cyclic AMP. On induction, the bcy1 and cyr1-3 bcy1 mutant cells produced the same levels of galactokinase and alpha-D-glucosidase as did the wild-type cells and fourfold-higher levels of invertase. Since galactokinase synthesis was severely repressed by glucose in the constitutive GAL81 mutants, irrespective of the cyr1-3 bcy1 genotype, cyclic AMP may not be involved in catabolite repression.

Adenylyl Cyclases↗
PubMed1983

Epidemiological studies on renal papillary necrosis with diabetes mellitus in Japan.

Eighty-six cases of renal papillary necrosis (RPN) published in Japan over the years 1949-1980 were studied. While several hundreds cases of RPN were reported in certain European countries and the USA, only 5 cases were published in Japan up until 1960. However, the number of case reports has increased to 28 over the 5 year period of 1976-1980. The ratio of diabetics (62 cases) to nondiabetics (24 cases) is about 2.6:1 and is the same as that reported by Lauer in the USA. In diabetics, RPN was more frequently seen in females (3.4:1) and at more advanced age. Frequency of bilateral occurrence was high (47.5%). The prevalence of the association of glomerulosclerosis (75.0%) was higher than that reported by Silverman et al. in the USA (47.1%). The Incidence of the association of disturbances of consciousness (29.5%) was similar to that reported by Edmondson et al.. It was concluded that the number of cases of RPN with diabetes mellitus in Japan started to increase about 20 years later than in the USA, and that the frequency of the association between RPN and diabetic glomerulosclerosis in Japan seems to be higher than in the USA. Furthermore, it was noted that RPN was frequently associated with hyperosmolar nonketotic diabetic coma.

Diabetic Coma↗
PubMed1983

Two cases of portal-systemic shunts demonstrated by portal venography performed by operative cannulation of ileocolic vein.

Two cases of portal-systemic shunt were presented. A 70 year-old cirrhotic female, who was suffered from mental confusion, underwent portal venography which demonstrated a large varicose vein connecting the inferior mesenteric vein with the left renal vein. The mean portal pressure was 15 cm saline. There were no esophagogastric varices. A 47 year-old cirrhotic female, who was admitted for evaluation of liver dysfunction found incidentally, underwent portal venography which revealed a dilated coronary vein connecting to the left renal vein. The portal pressure was 23 cm saline. There was no evidence of esophageal varices. Portal venography was performed through the ileocolic vein in both cases. In general, bleeding varices may develop most commonly in coronary-azygous system and less frequently in the territory of the superior and inferior mesenteric veins. On the contrary, retroperitoneal portal-systemic shunts is likely to cause hepatic encephalopathy rather than to develop bleeding varices. Thus, it is necessary to perform abdominal angiography in patients with hematochezia of unknown etiology or recurrent episodes of hepatic encephalopathy.

Aged↗
PubMed1983

[Fontanelle pressure in infantile hydrocephalus--with special reference to 6 cases of hydrocephalus with normal head circumference and without shunting operation].

Follow-up study on ICP was carried out in 6 cases of hydrocephalus within normal head circumference for 8-9 months after birth. There were no cases with shunting operation. Abnormal plateau-like wave was recorded in 2 cases with myelomeningocele during follow-up period. In other cases of postemeningitic hydrocephalus, almost normal baseline pressure without abnormal pressure wave was recorded and all showed favorable morbidity (function). These results showed the importance of follow-up study on ICP for 9 months after birth in cases of hydrocephalus without large head circumference and shunting operation should be recommended in cases showing abnormal pressure wave recorded during follow-up period.

Age Factors↗
PubMed1982

Isolation and characterization of yeast mutants deficient in adenylate cyclase and cAMP-dependent protein kinase.

Mutants of Saccharomyces cerevisiae that require cAMP for growth have been isolated. Some of the mutants isolated were deficient in adenylate cyclase activity and mapped at a locus, cyr1, located near the centromere of chromosome X. Growth of cells carrying the cyr1 mutation was arrested at the G1 phase of the yeast cell cycle in the absence of cAMP. The cyr1 mutation was suppressed by a secondary mutation designated bcy1. The bcy1 mutation bypassed the need for cAMP for growth. The bcy1 mutants had extremely low levels of cAMP-binding protein and cAMP-dependent protein kinase but produced a high level of cAMP-independent protein kinase. The results indicate that cAMP is an essential factor for yeast cells to proceed through the cell cycle via the activation of protein kinase.

Adenylyl Cyclases↗
PubMed1982

Cyclic AMP may not be involved in catabolite repression in Saccharomyes cerevisiae: evidence from mutants capable of utilizing it as an adenine source.

Mutants able to utilize 5'-AMP or cyclic AMP as the adenine source were isolated from an ade6 ade10 double mutant by ethyl methane sulfonate mutagenesis. A single amp1 mutation, primarily selected on 5'-AMP medium, confers the phenotype for utilization of exogenous 5'-AMP as the adenine source. From the ade6 ade10 amp1 triple mutant, a mutant able to utilize cyclic AMP was isolated, and the mutant phenotype was proven to be due to the simultaneous occurrence of triple mutations designated as cam1, cam2, and cam3. The cam3 mutation, but not cam1 or cam2, also confers the phenotype for utilizing 5'-AMP, the same phenotype as the amp1 mutation. All of these mutations are recessive to the respective wild-type counterparts. Cells having the ade6 ade10 amp1 cam1 cam2 cam3 genotype showed significant ability to take up exogenous cyclic AMP, whereas no differences were observed in cyclic AMP phosphodiesterase activity in comparison with that of the original strains used in the mutant isolation. Since glucose severely repressed galactokinase synthesis in the constitutive GAL81 mutant having the ade6 ade10 amp1 cam1 cam2 cam3 genotype, irrespective of the presence or absence of cyclic AMP in the medium, it was suggested that cyclic AMP is not involved in the mechanism of catabolite repression in Saccharomyces cerevisiae. It does, however, have a stimulative effect on the galactokinase synthesis in the GAL81 mutant in the absence of glucose.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1982

2-micrometers DNA-like plasmids in the osmophilic haploid yeast Saccharomyces rouxii.

DNA plasmids were detected in two independent strains of Saccharomyces rouxii among 100 yeast strains other than Saccharomyces cerevisiae tested. The plasmids, pSR1 and pSR2, had almost the same mass (approximately 4 X 10(6) daltons) as 2-micrometers DNA of S. cerevisiae. pSR1 and pSR2 gave identical restriction maps with restriction endonucleases BamHI, EcoRI, HincII, HindIII, and XhoI, and both lacked restriction sites for PstI, SalI, and SmaI. These maps, however, differed significantly from that of S. cerevisiae 2-micrometers DNA. Restriction analysis also revealed two isomeric forms of each plasmid and suggested the presence of a pair of inverted repeat sequences in the molecules where intramolecular recombination took place. DNA-DNA hybridization between the pSR1 and pSR2 DNAs indicated significant homology between their base sequences, whereas no homology was detected between pSR1 and pJDB219, a chimeric plasmid constructed from a whole molecule of 2-micrometers DNA, plasmid pMB9, and a 1.2-kilobase DNA fragment of S. cerevisiae bearing the LEU2 gene. A chimeric plasmid constructed with pSR1 and YIp1, the larger EcoRI-SalI fragment of pBR322 ligated with a 6.1-kilobase DNA fragment of S. cerevisiae bearing the HIS3 gene, could replicate autonomously in an S. cerevisiae host and produced isomers, presumably by intramolecular recombination at the inverted repeats.

Base Sequence↗
PubMed1982

Identification of the genetic locus for the structural gene and a new regulatory gene for the synthesis of repressible alkaline phosphatase in Saccharomyces cerevisiae.

Two lines of evidence showed that the PHO8 gene encodes the structure of repressible, nonspecific alkaline phosphatase in Saccharomyces cerevisiae: (i) the enzyme produced by a temperature-sensitive pho8 mutant at the permissive temperature (25 degrees C) was more thermolabile than that of the wild-type strain, and (ii) the PHO8 gene showed a gene dosage effect on the enzyme activity. The pho8 locus has been mapped on chromosome IV, 8 centimorgans distal to rna3. A new mutant carrying the pho9 gene was isolated which lacks repressible alkaline phosphatase, but has the normal phenotype for the synthesis of repressible acid phosphatase. The pho9 gene segregated independently of all known pho-regulatory genes and did not show the gene dosage effect on repressible alkaline phosphatase activity. The pho9/pho9 diploid hardly sporulated and showed no commitment to intragenic recombination when it was inoculated on sporulation medium. Hence the pho9 mutant has a phenotype similar to the pep4 mutant, which was isolated as a pleiotropic mutant with reduced levels of proteinases A and B and carboxypeptidase Y. An allelism test indicated that pho9 and pep4 are allelic.

Alkaline Phosphatase↗
PubMed1982

Plasma soluble fibrin monomer complexes in the development of diabetic retinopathy.

To elucidate the relationship between plasma soluble fibrin monomer complexes (SFMC) and retinal or vitreous hemorrhages, 11 diabetics were studied for 15 months. The levels of SFMC in 3 out of the 11 cases were elevated prior to hemorrhages and in the other 8 cases SFMC levels were elevated after hemorrhages. With regard to fibrinogen (Fbg) concentrations, there was no significant difference between the values before and after hemorrhages. The plasma glucose levels did not change significantly during the observation. It was concluded that the SFMC level was not only an indicator of the intracapillary generation of thrombin but an important factor affecting the development of diabetic retinopathy.

Aged↗
PubMed1981

Cloning of the HIS5 gene of Saccharomyces cerevisiae by yeast transformation.

A yeast DNA fragment complementing a yeast his5 mutation was cloned on a shuttle vector, YRp7, by transformation of the yeast host with plasmid DNA prepared from a gene bank constructed in the Escherichia coli host. That the DNA fragment contains the yeast HIS5 gene was confirmed by the integration of the cloned plasmid into the his5 region of the yeast chromosome. The cloned yeast HIS5 gene weakly complemented the E. coli hisC mutation and gave rise to a slow-growing E. coli transformant without addition of histidine. From the slow-growing culture, rapidly growing variants of E. coli were easily obtained by mutations either in the bacterial chromosome or in the plasmid.

Cloning, Molecular↗
PubMed1981

Clinical progression of giant-axonal neuropathy over a twelve year period.

Giant-axonal neuropathy (GAN), a chronic peripheral neuropathy with associated Central Nervous System dysfunction and tight curly hair, is described in a 17-year-old girl. Biopsies of this girl's muscle and nerve are characteristic of this condition. Her clinical course over a 12 year period characterizes a disease of a slowly progressive nature.

Axons↗
PubMed1981

Structure and function of the PHO82-pho4 locus controlling the synthesis of repressible acid phosphatase of Saccharomyces cerevisiae.

pho4 mutants of Saccharomyces cerevisiae, although rare among phosphatase-negative mutants isolated from wild-type strains, were isolated efficiently from pho80, pho85, or pho80 pho85 strains. The distribution of these pho4 mutants over the pho4 locus was determined by analyzing random spores of two- and three-factor crosses. The pho4-4 mutation confers temperature-sensitive synthesis of repressible acid phosphatase. An intragenic suppressor for the pho4-12 allele results in the temperature-sensitive synthesis of repressible acid phosphatase. Recombination between these sites occurs at 1.0 to 3.0%, the highest for any pair of sites within the pho4 locus. All these results strongly indicate that the information of the pho4 locus is translated into a protein. The PHO82 site was mapped inside the pho4 locus by random spore analysis. The order met10-pho4-1PHO82-1-pho4-9 on the right arm of chromosome VI was confirmed by tetrad analysis. Doubly heterozygous diploids, pho3 PHO82c PHO4+/pho3 pho82+ pho4, produce variable amounts of repressible acid phosphatase under repressive conditions depending on the combination of PHO82c and pho4 alleles. This phenomenon may reflect the constitutive production of the pho82+-pho4 product in the repressed condition, which interferes with the function of the PHO82c-PHO4+ product. The earlier model for the function of the PHO82-pho4 cluster, in which the PHO82 site acts as an operator of the pho4 gene, has been revised to a model in which the PHO82 site codes for the part of the pho4 protein that has affinity for the regulatory protein encoded by the pho80 and pho85 genes.

Acid Phosphatase↗