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S Kakinuma

Publications and source records attributed to S Kakinuma.

53 records · Page 3Linked to original sources
PubMed1993

Biosynthesis of the pradimicin family of antibiotics. I. Generation and selection of pradimicin-nonproducing mutants.

Germinated spores of Actinomadura verrucosospora subsp. neohibisca E-40, a high pradimicins producer, were mutagenized by N-methyl-N'-nitro-N-nitrosoguanidine and/or UV treatment. Thirty-seven mutants which did not produce pradimicin were selected to test for cosynthesis ability, and classified into nine classes. On the basis of their cosynthesis ability and bioconversion results, we concluded that strain JN-213 (class III) was a true converter and that strains JN-219 (class IV), JN-47 (class V) and JNU-46 (class VI) were secretors accumulating biosynthetic intermediates of pradimicin, and that strains JN-59 (class VII), JN-58 (class VIII) and JN-207 (class IX) were producers of shunt metabolites of pradimicin biosynthesis. TLC and HPLC analyses of the fermentation broths of individual strains showed that 8 new compounds were produced along with pradinone I, pradimicinone I, 11-O-demethylpradimicinone II and 7-O-methylpradimicinone II.

Actinomycetaceae↗
PubMed1993

Biosynthesis of the pradimicin family of antibiotics. II. Fermentation, isolation and structure determination of metabolites associated with the pradimicins biosynthesis.

Ten metabolites produced by 4 mutants derived from Actinomadura verrucosospora subsp. neohibisca E-40, a high pradimicins producer, were isolated and their structures were determined. Strain JN-219 produced 3 novel analogs of the pradimicin A aglycone, i.e. 11-O-demethyl-7-methoxypradinone II and 11-O-demethylpradinones I and II together with a known aglycone analog, pradinone I, while the metabolites from strain JN-47 were determined to be 2 new aglycone analogs, 11-O-demethylpradimicinone I and 11-O-demethyl-7-methoxypradimicinone II and a known aglycone analog, 11-O-demethylpradimicinone II (11dM-PMN II). Products of strain JN-207 were identified as 11-O-demethyl-6-deoxypradinone I and 11dM-PMN II. Interestingly, a new pradimicin analog, 7-hydroxypradimicin A was isolated from strain JN-58 together with a new aglycone analog, pradimicinone II and 11dM-PMN II. None of these metabolites showed antifungal activity.

Actinomycetaceae↗
PubMed1993

Biosynthesis of the pradimicin family of antibiotics. III. Biosynthetic pathway of both pradimicins and benanomicins.

The biosynthetic pathway of the pradimicin-benanomicin family of antibiotics was investigated by using sinefungin and blocked mutants derived from Actinomadura verrucosospora subsp. neohibisca E-40 (a high pradimicin producer) or Actinomadura sp. AB1236 (a benanomicin producer). Addition of sinefungin to strain E-40, pradimicin A aglycone-producing mutant or strain AB1236 inhibited the formation of 11-O-demethyl-7-methoxypradinone II (11dM-7M-PN II), resulting in the accumulation of 11-O-demethylpradimicinone II and pradimicinone II. By feeding pradimicin A aglycone and its analogs to mutants blocked early in pradimicin or benanomicin biosynthesis, the following results were obtained: 11-O-demethylpradinone II, 11dM-7M-PN II 11-O-demethylpradinone I, 11-O-demethylpradimicinone I and pradimicinone I were converted to pradimicin A or benanomicin A; the remaining 6 aglycone analogs were not incorporated into the antibiotics. Pradimicin B, dexylosylpradimicin C and dexylosylbenanomicin A were converted to pradimicin A, pradimicin C and benanomicin A, respectively. A biosynthetic pathway for the antibiotics is proposed.

Actinomycetales↗
PubMed1993

Pradimicins T1 and T2, new antifungal antibiotics produced by an actinomycete. II. Structures and biosynthesis.

Pradimicins T1 and T2 are new members of the pradimicin family of antibiotics produced by an actinomycete strain AA3798. Pradimicins T1 and T2 are dihydrobenzo[a]naphthacenequinones substituted with 3 and 2 sugar moieties, respectively. The salient feature in their structures is an L-xylose attached to the phenolic hydroxyl group at C-11. Bioconversion experiments using a blocked mutant B-54 of strain AA3798 not only explored a plausible biosynthetic pathway of pradimicins T1 and T2, but also provided evidence of 5S,6S configuration.

Actinomycetaceae↗
PubMed1991

Cloning of large DNA fragments, which hybridize with actinorhodin biosynthesis genes, from kalafungin and nanaomycin A methyl ester producers and identification of genes for kalafungin biosynthesis of the kalafungin producer.

Large actI, III-homologous DNA fragments were isolated from genomic libraries of the strains that produce the benzoisochromanequinone antibiotics kalafungin and nanaomycin A methyl ester, Streptomyces tanashiensis strain Kala and Streptomyces sp. OM-173, respectively. These libraries were prepared in Escherichia coli JM108 by using a novel Streptomyces-E. coli bifunctional cosmid, pKU205, and screened with polyketide synthase genes (actI and III) for actinorhodin biosynthesis from Streptomyces coelicolor A3(2) as probes. The cloned DNA fragments (28 and 42 kb) were analyzed by hybridization with DNA containing actinorhodin biosynthetic genes (actI, II, III, IV, VA, VB, VI and VII). Both fragments hybridized with the actI, III, VA and VI regions, but not with the actII, IV, VB and VII regions. The cloned fragment of S. tanashiensis DNA was analyzed by complementation tests with kalafungin-nonproducing mutants. Seven genes (kalI approximately VII), which correspond to seven steps in kalafungin biosynthesis, were found to be located on a 14 kb continuous DNA fragment. Five of the genes were located on the regions homologous to the genes for actinorhodin biosynthesis, but the other two genes were not. Although kalafungin is an intermediate or shunt product in actinorhodin biosynthesis in S. coelicolor A3(2), the genes for kalafungin biosynthesis in S. tanashiensis are not identical with those in S. coelicolor A3(2).

Anthraquinones↗
PubMed1990

Biosynthesis of kalafungin in Streptomyces tanashiensis.

The mutants of Streptomyces tanashiensis strain Kala, which were specifically blocked in the synthesis of the benzoisochromanequinone antibiotic kalafungin, were isolated and classified into seven phenotypic classes on the basis of the antibiotic activity and cosynthetic properties. The polarity of cosynthetic reactions and the production of kalafungin by a converter strain showed that the seven mutant classes could be arranged in the most probable linear sequence of biosynthetic blocks. Since kalafungin, which closely resembles the undimerized form of actinorhodin, was accumulated in one of the biosynthetically blocked mutants of the actinorhodin-producing Streptomyces coelicolor A3(2), the cosynthesis between kalafungin-nonproducing mutants of S. tanashiensis and actinorhodin-nonproducing mutants of S. coelicolor was performed. The results of these experiments showed that the early steps in kalafungin biosynthesis in S. tanashiensis and actinorhodin biosynthesis in S. coelicolor were similar, but the entire biosynthetic pathway of kalafungin in these two streptomycetes was not identical.

Antifungal Agents↗
PubMed1990

Isolation of restriction-reduced mutants from Streptomyces.

Restriction-reduced mutants were isolated from Streptomyces rosa subsp. notoensis KA301 and S. tanashiensis strain Kala which produce the benzoisochromanequinone antibiotics nanaomycin and kalafungin, respectively. The mutants of S. rosa, which can be transformed with a multi-copy plasmid and in which the actinophage Pa16 can propagate, were selected. They were transformed with a single-copy plasmid propagated in S. lividans TK24, and with its modified plasmid propagated in the mutant at higher efficiency. The mutants of S. tanashiensis were selected by their capability to be transformed with a multi-copy plasmid. The efficiency of transformation with a single-copy plasmid propagated in S. lividans TK24 was low, but was much increased by heating the protoplasts at 42 degrees C for 15 min prior to the transformation. These mutants derived from both strains probably lack at least one of their restriction systems.

Escherichia coli↗
PubMed1987

Molecular cloning and sequencing of cDNA encoding goat pre alpha-lactalbumin.

In poly(A)+RNA extracted from a lactating goat mammary gland, mRNA of about 750 nucleotides was shown to encode pre alpha-lactalbumin by using in vitro translation and immunoprecipitation. From the total poly(A)+RNA, the cDNA library was constructed using the Escherichia coli plasmid pUC18; it was screened with the oligodeoxyribonucleotide probe corresponding to the amino acid sequence of Trp60-Gln65 of goat alpha-lactalbumin. A plasmid containing almost full-length cDNA of goat pre alpha-lactalbumin, pGLA-1, was identified. The cDNA insert of pGLA-1 comprises 727 base pairs and contains the signal peptide and mature protein sequence.

Amino Acid Sequence↗
PubMed1986

[A study of blood coagulation and fibrinolysis in a small-for- gestational-age infant birth group].

In order to approach from the aspect of blood coagulation and fibrinolysis the reason for the birth of SGA (small for gestational age) infants, we studied the blood coagulation and fibrinolysis capacity of maternal venous blood in the 36th and 37th weeks after conception employing 54 cases in which were no abnormality was seen during pregnancy up to delivery, and we also studied the relationship of the body weight at delivery and arrived at the following conclusions. In the SGA infant birth group there was a tendency toward acceleration of blood coagulation, acceleration of blood platelet aggregation and inhibition of fibrinolysis when compared with two other groups i.e. AGA (appropriate for gestational age) and LGA (large for gestational age) infant birth groups. In the SGA infant birth group in particular there was seen a statistically significant reduction in prothrombin time (p less than 0.002) when compared with the other two groups. A correlation was noted between prothrombin time for maternal blood and the infant's body weight at birth (r = 0.38446, p less than 0.01), and the shorter the prothrombin time for maternal blood in the late stage of pregnancy, the lower the infant's body weight tended to be at birth. The results indicate that these changes in blood coagulation and fibrinolysis may influence the decrease in the blood output of the uterine placenta, and it may be assumed that this causes the birth of SGA infants. Furthermore, the prothrombin time values become one of the parameters used in forecasting an SGA infant's birth, and this should to be considered as a new fibrinolytic therapy for SGA infants.

Blood Coagulation↗
PubMed1985

[Blood coagulation and fibrinolysis in cord blood with reference to birth weight].

To clarify the hemocoagulative and fibrinolytic dynamics of the perinatal period and also to seek the cause of SGA (small for gestational age) baby birth, the coagulation and fibrinolysis of the cord blood were examined, and moreover a comparison with the maternal blood, discussion on the difference in birth weight, and an examination of the difference due to the sex of babies were made in 68 cases with full-term, vaginal, spontaneous delivery, and the following conclusions were reached. In comparison with maternal blood, cord blood significantly showed any of the following: Prolongations of the prothrombin time, and the activated partial thromboplastin time, a decrease in fibrinogen, and a decrease in the platelet aggregation, antithrombin III, and plasminogen. In addition, high values for thromboxane B2 and 6-ketoprostaglandin F1 alpha were observed. In the SGA group, significant decreases were observed in the platelet count, antithrombin III, plasminogen, and alpha 2-plasmin inhibitor as compared with the AGA (appropriate for gestational age) and LGA (large for gestational age) baby groups. No sex difference was observed in the hemocoagulative and fibrinolytic capacities of the cord blood. These hemocoagulative and fibrinolytic capacities, particularly changes in the fibrinolytic system observed in the SGA group, seem to be attributable to chronic DIC (disseminated intravascular coagulation) and mild acidosis due to various stresses during pregnancy and at parturition, in turn due to immaturity of the liver in babies.

Birth Weight↗
PubMed1984

A cytosolic cyclic AMP-dependent protein kinase in Dictyostelium discoideum. II. Developmental regulation.

The cAMP-dependent protein kinase of the cellular slime mold, Dictyostelium discoideum, is developmentally regulated; there is an approximately 4-fold increase in activity during development. The incorporation of [3H]leucine into the enzyme demonstrates that there is de novo synthesis of the cAMP-dependent protein kinase. The activities of the catalytic and regulatory subunits increase in parallel. The maximal rate of increase of cAMP-dependent protein kinase activity precedes "tip" formation, a stage of development characterized by a sharp increase in mRNA complexity. The high level of cAMP-dependent protein kinase activity, attained at this stage of development, persists when aggregates are dispersed and the amoebae are kept in suspension without added cAMP. The synthesis of the developmentally regulated mRNAs under these conditions is dependent on exogenous cAMP. The increase in cAMP-dependent protein kinase activity during development does not require sustained cell-cell contact insofar as it occurs in single cell suspensions of amoebae. Furthermore, the increase does not require exogenous cAMP, although added cAMP stimulates the synthesis of the enzyme to a level higher than that found, when cAMP is not added. These observations support the hypothesis that in D. discoideum cAMP-dependent protein kinase mediates the effects of cAMP on development.

Cyclic AMP↗
PubMed1984

An increase of cAMP-dependent protein kinase during development in Polysphondylium pallidum.

Polysphondylium pallidum is a cellular slime mold in which, unlike in Dictyostelium discoideum, cAMP is not the chemotactic agent. The occurrence of a cAMP-dependent protein kinase in D. discoideum was demonstrated earlier and we suggested that it may mediate the intracellular effects of cAMP on the development of the organism, particularly since an increase in the amount of the enzyme during development was noted. In D. discoideum cAMP plays a dual role insofar as it serves both as chemotactic agent and as second messenger; it was of interest therefore, to determine whether a cAMP-dependent protein kinase occurred in P. pallidum. We found a cAMP-dependent protein kinase in P. pallidum using Kemptide as substrate. The regulatory subunit of the enzyme has an apparent molecular weight of 41,000 and seems to be similar in its properties with that isolated earlier from D. discoideum. The cAMP-dependent protein kinase catalytic subunits from the two species are also similar. Furthermore, there is a developmentally regulated, parallel, two- to threefold increase in the two subunits of the cAMP-dependent protein kinase in P. pallidum. The increase occurs before aggregates are formed. These findings are compatible with a role of the intracellular cAMP and of the cAMP-dependent protein kinase in the development of P. pallidum.

Darkness↗
PubMed1984

Differential cellular distribution of cAMP-dependent protein kinase during development of Dictyostelium discoideum.

It was shown previously by us that cAMP-dependent protein kinase activity in the cellular slime mold Dictyostelium discoideum increased during the early stages of development. Results from other laboratories showed that during the subsequent stage of cell differentiation and positioning, the accumulation of a number of prespore mRNAs and proteins (but not prestalk mRNAs and proteins) was dependent upon cAMP. The present communication describes the cellular distribution of the cAMP-dependent protein kinase at that stage of development. Pseudoplasmodia were disrupted, and prespore cells were separated from prestalk cells by sedimentation through a Percoll gradient. Prespore cells had approximately 4-5 times as much of both the catalytic and regulatory subunits of the cAMP-dependent protein kinase as did the prestalk cells. That the increase of cAMP-dependent protein kinase during development reflected de novo synthesis of the enzyme in both prespore and prestalk cells was demonstrated on the basis of [(3)H]leucine incorporation into the regulatory subunit. The findings are consistent with a role of the cAMP-dependent protein kinase in mediating the effects of cAMP on the synthesis of prespore-specific mRNAs and proteins at the stage at which cAMP appears to be required for the cell type-specific syntheses.

Journal Article↗
PubMedDate not supplied

Intraoperative radiotherapy and bypass surgery for unresectable pancreatic cancer.

BACKGROUND/AIMS: Conflicting results have been reported concerning the usefulness of radiotherapy for unresectable pancreatic cancer. We evaluated the clinical efficacy of intraoperative radiotherapy and/or external beam radiotherapy in combination with bypass surgery. METHODOLOGY: Twenty-six patients with unresectable pancreatic cancer (16 in Stage II-III and 10 in Stage IV) were treated with intraoperative radiotherapy plus external beam radiotherapy (16 patients) or intraoperative radiotherapy alone (10 patients). The dose of intraoperative radiotherapy was either 25 or 30 Gy and the external beam radiotherapy dose was 31-60 Gy. The feasibility and clinical outcome were analyzed. RESULTS: The median survival time for Stage II-III and Stage IV were 11.5 and 6.5 months, respectively. The difference between Stage II-III and Stage IV in survival patterns was statistically significant (P < 0.05). For Stage II-III patients, the survival curves between the groups of intraoperative radiotherapy plus external beam radiotherapy and intraoperative radiotherapy alone were not significantly different, and only performance status was a significant factor in the prognosis (P < 0.05). Gastrointestinal bleeding was noted in 8%, but did not occur in the patients treated with an external beam radiotherapy dose less than 50 Gy. Palliative radiation was successfully performed to relieve pain, jaundice and appetite-loss and to shorten the hospital stay. CONCLUSIONS: The combination therapy with intraoperative radiotherapy and bypass surgery is considered to be tolerable and effective for unresectable pancreatic cancer, and also may improve the quality of life of the patients.

Aged↗