Oxidation of 1,5-anhydro-D-glucitol to 1,5-anhydro-D-fructose catalyzed by an enzyme from bacterial membranes

Bacteria which grow on 1,5-anhydro-D-glucitol (AG) were isolated from soil. One such strain showing the highest AG-assimilating activity was further characterized and identified as a new strain of the Pseudomonas family (named Pseudomonas sp. NK-85001). A subcellular membranous fraction obtained from this strain catalyzed the oxidation of AG to 1,5-anhydro-D-fructose. This oxidation reaction consumed molecular oxygen as the terminal electron acceptor. The AG-oxidizing activity was further purified after solubilization. The AG oxidation catalyzed by this solubilized enzyme utilized molecular oxygen only in the presence of an electron mediator such as 2,6-dichlorophenolindophenol or phenazine methosulfate. Thus, the enzyme was suggested to be a dehydrogenase rather than an oxidase. The solubilized enzyme preparation also showed a strict substrate specificity. The observed specificity indicated that application of the enzyme for AG assay in clinical samples might be possible.

A functional study of a case of glucagonoma exhibiting typical glucagonoma syndrome

A 46-year-old man had a 7-year history of severe rash, which was then diagnosed as necrolytic migratory erythema. He had a weight loss of 6 kg, abnormal glucose tolerance test findings, anemia, glossitis, hair loss, and hypoproteinemia. Plasma amino acids levels were significantly decreased, and the fasting plasma glucagon (IRG) level was high at 5000 to 8000 pg/ml. Circulating IRG significantly increased after oral glucose loading, meal ingestion, and arginine infusion, and decreased with somatostatin infusion and insulin-induced hypoglycemia. No other gut or pancreatic hormone levels in plasma were elevated. Plasma IRG was eluted by gel-filtration, mainly in the position of true glucagon (MW 3500) by antiserum 30K. The rash was markedly improved after infusion of amino acids. Computerized tomography (CT) scan and celiac angiography revealed a large pancreatic tumor with multiple liver and lymph node metastases. The pancreatic tumor was totally resected, and was identified as glucagonoma by immunohistochemical technique. Since the plasma IRG levels remained high after surgery, the patient received dimethyltriazenoimidazole carboxamide therapy. After several courses of this treatment, plasma IRG levels decreased to 1000 to 2000 pg/ml, and the hepatic metastases were remarkably diminished in size.

Biological properties of griseolic acid, a cyclic AMP phosphodiesterase inhibitor with an adenine group

Griseolic acid inhibited cAMP phosphodiesterase (PDE) at low concentrations, the I50 being of the order of 0.01-0.1 microM. Administration of griseolic acid to rats increased the cAMP level in liver and plasma several-fold. It increased glycogen degradation in mouse liver and stimulated lipolysis in isolated rat fat cells. Griseolic acid did not block the adenosine-elicited accumulation of cAMP in guinea pig brain slices. It had no effect on cAMP-dependent protein kinase from rat liver nor on the adenyl cyclase from rat brain.

Griseolic acid, an inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase. II. The structure of griseolic acid

Griseolic acid, a potent inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase, was isolated from the fermentation broth of Streptomyces griseoaurantiacus SANK 63479. Treatment of griseolic acid with HCl-MeOH gave adenine and pseudo-sugar. The structure of griseolic acid, adenine nucleoside type structure, was elucidated by chemical degradation and X-ray analysis, and was shown to be structure 1.

Griseolic acid, an inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase. I. Taxonomy, isolation and characterization

Griseolic acid, a potent inhibitor of cyclic adenosine 3',5'-monophosphate (cyclic AMP) phosphodiesterase (EC 3.1.4.17) was isolated from the cultured broth of Streptomyces griseoaurantiacus SANK 63479. Griseolic acid has an adenine moiety and two carboxyl groups and possesses the molecular formula C14H13N5O8. Griseolic acid inhibited cyclic AMP phosphodiesterase competitively with regard to cyclic AMP, the substrate and the resulting Ki value was 0.26 microM. Griseolic acid showed the most potent inhibitory effect on rat aorta cyclic AMP phosphodiesterase among the enzymes of several rat organs tested. The plasma level of cyclic AMP was increased when griseolic acid was subcutaneously injected rats.

Ambulatory electrocardiograms obtained by Holter monitoring system in patients with permanent demand pacemakers

Ventricular inhibited demand pacemakers (VVI) were implanted in 27 patients with complete A-V block and pacemaker arrhythmias were analyzed by Holter system ambulatory electrocardiograms and conventional electrocardiograms. With Holter ECG, 13 patients showed myopotential inhibition, 5 patients had sensing failure and premature ventricular contractions (PVC) were observed in all patients. On the contrary, myopotential inhibition and sensing failure were not detected by conventional ECG and the detection rate of PVC was only 30%. The transient recovery of A-V conduction was observed in 14 of 27 patients with Holter ECG, but was not detected by conventional ECG. The Holter system ambulatory electrocardiogram clearly demonstrated the complex cardiac arrhythmias. Therefore, it is useful for monitoring arrhythmias caused by VVI pacemakers.

[A case of ovarian carcinoma preceded by intracranial metastasis]

A 28-year-old woman with primary ovarian carcinoma which was found with intracranial metastasis is reported. The patient was operated on because of metastatic brain tumor with unknown primary lesion. Subsequently, left ovarian tumor was found, and left salpingo-oophorectomy was performed. The histological diagnosis was endometrioid carcinoma. A review of the literature shows that intracranial metastasis by ovarian carcinoma is very rare. The incidence is lower than 2.1%. The present case in which intracranial metastasis manifested itself before primary ovarian carcinoma seems to be extremely rare.

Cholangiocellular carcinoma associated with multiple liver cysts

A 46-year-old woman visited our outpatient clinic complaining of dull right hypochondrial pain. Ultrasonography revealed four cysts in the right lobe of the liver. Arteriography and CT could not determine whether these cysts were benign or malignant. Because one of these cysts contained chocolate-colored fluid, amebic abscess was suspected, and the cyst was drained. No amebae were found in the cultured exudate, and fresh bleeding continued; therefore, laparotomy was performed. A tumor was present on the surface of the liver. Right lobectomy was performed. The resected specimen contained one nonepithelialized cyst which was invaded by surrounding cholangiocellular carcinoma and three epithelialized cysts. Preoperative diagnosis of this kind of cholangiocellular carcinoma seems to be very difficult. Recently cholangiocellular carcinoma associated with developmental cysts has been classified as a new entity different from cystadenocarcinoma. Cholangiocarcinoma, which belongs to this group, seems to deserve special attention.

[Mitral valve prolapse in patients with anorexia nervosa]

Mitral valve prolapse (MVP) is frequently observed in patients with low body weight and/or skeletal abnormalities such as pectus excavatum and straight spines. There may be a variety of associated autonomic dysfunctions. Whether MVP is a complication of anorexia nervosa which has similar clinical features, including weight loss, skeletal abnormalities and autonomic dysfunctions, has not been reported. The present study was an investigation of the incidence of MVP and cardiac function in anorexia nervosa by echocardiography. Two-dimensional and M-mode echocardiography, and systolic time intervals were evaluated for 19 women with anorexia nervosa, from 13 to 25 years of age and having a mean age of 18.2 years. Their body weights ranged from 23.9 to 43 kg with a mean of 33.5 kg, and were at least 25% less than their ideal body weights (ranges were from 25 to 52%). The same studies were performed for 19 women with MVP diagnosed echocardiographically and without anorexia nervosa as controls. Their ages ranged from 14 to 26 years. Results were as follows: MVP was observed in 74% of patients with anorexia nervosa. The mean heart rates were 51.7 and 70.5/min in the anorexia nervosa and control groups, respectively. A significant difference (p less than 0.001) was observed between the two groups. The mean heart rate of patients with anorexia nervosa having MVP of both leaflets and no MVP were 45.8 and 59.0/min, respectively. The difference between these two sub-groups was statistically significant (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Homology is not required for recombination mediated by DNA gyrase of Escherichia coli

We have previously shown that DNA gyrase of Escherichia coli can promote recombination between heterologous DNAs in a cell-free system (Ikeda et al. 1982). In the present paper, we have studied the nucleotide sequences of several recombination junctions of lambda-pBR322 recombinants and found that there were not more than three-basepair homologies between the parental DNAs in six combinations of the lambda and pBR322 recombination sites. Based on this and previous results, we concluded that homology was not required for the DNA gyrase-mediated recombination. Furthermore, the structures of the recombinant DNAs we have analyzed suggest the occurrence of multiple cross-overs in our in vitro system.

Terferol, an inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase. I. Isolation and characterization

Terferol, a new inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase (EC 3.1.4.17, cAMP-PDE), was isolated from the cultured broth of Streptomyces showdoensis SANK 65080. It was found to have the molecular formula C19H16O3 and to possess inhibitory activity not only against cAMP-PDE but also against cyclic guanosine 3',5'-monophosphate phosphodiesterase (cGMP-PDE) from various rat tissues. The terferol concentration required for 50% inhibition of cAMP-PDE was 0.82 microM.

Terferol, an inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase. II. Structural elucidation

Streptomyces showdoensis SANK 65080 produced terferol, an inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase (cAMP-PDE). NMR spectrometry and X-ray analysis were used to determine the structure of the compound, a new member of the terphenyl family.

Molecular cloning and sequence determination of the nuclear gene coding for mitochondrial elongation factor Tu of Saccharomyces cerevisiae

A 3.1-kilobase Bgl II fragment of Saccharomyces cerevisiae carrying the nuclear gene encoding the mitochondrial polypeptide chain elongation factor (EF) Tu has been cloned on pBR327 to yield a chimeric plasmid pYYB. The identification of the gene designated as tufM was based on the cross-hybridization with the Escherichia coli tufB gene, under low stringency conditions. The complete nucleotide sequence of the yeast tufM gene was established together with its 5'- and 3'-flanking regions. The sequence contained 1,311 nucleotides coding for a protein of 437 amino acids with a calculated Mr of 47,980. The nucleotide sequence and the deduced amino acid sequence of tufM were 60% and 66% homologous, respectively, to the corresponding sequences of E. coli tufA, when aligned to obtain the maximal homology. Plasmid YRpYB was then constructed by cloning the 2.5-kilobase EcoRI fragment of pYYB carrying tufM into a yeast cloning vector YRp-7. A mRNA hybridizable with tufM was isolated from the total mRNA of S. cerevisiae D13-1A transformed with YRpYB and translated in the reticulocyte lysate. The mRNA could direct the synthesis of a protein with Mr 48,000, which was immunoprecipitated with an anti-E. coli EF-Tu antibody but not with an antibody against yeast cytoplasmic EF-1 alpha. The results indicate that the tufM gene is a nuclear gene coding for the yeast mitochondrial EF-Tu.

Illegitimate recombination mediated in vitro by DNA gyrase of Escherichia coli: structure of recombinant DNA molecules

We have developed a cell-free system from Escherichia coli for studying illegitimate recombination between nonhomologous DNA molecules. The recombination is stimulated by oxolinic acid, an inhibitor of DNA gyrase. The stimulation is abolished by coumermycin A1 and is not found in extracts of nalidixic acid-resistant (gyrA) mutants. We therefore inferred that DNA gyrase directly participates in illegitimate recombination, at least in the presence of oxolinic acid [Ikeda, H., Moriya, K. & Matsumoto, T. (1981) Cold Spring Harbor Symp. Quant. Biol. 45, 399--408]. The structure of recombinant DNA molecules formed in the presence of oxolinic acid from a cross between phage lambda and plasmid pBR322 DNAs was analyzed by heteroduplex mapping. Among nine isolates tested, two recombinants were formed by the insertion of the plasmid into the lambda genome. The seven other recombinants had more complicated genome structures. Insertion of pBR322 was accompanied by a deletion on one of the genomes. In all cases, the end points of deletions coincided with one end of the pBR322 insertion. Recombination sites seemed to be distributed randomly on the lambda and pBR322 genomes. Analysis of nucleotide sequences of the recombination junctions proved that the crossover took place between nonhomologous DNA sequences. A model for DNA gyrase-mediated illegitimate recombination is discussed.

Enzymatic conversion of cephamycin C by D-amino acid oxidase from Trigonopsis variabilis

D-Amino acid oxidase (EC 1.4.3.3) systems from Trigonopsis variabilis SANK 59963 were found to catalyze cephamycin C. The reaction products were assigned to 7 beta-(5-carboxy-5-oxovalerylamido)-7 alpha-methoxy-3-carbamoyl-3-cephem-4-carboxylic acid, and 7 beta-(4-carboxy-butyrylamido)-7 alpha-methoxy-3-carbamoyl-3-cephem-4-carboxylic acid, respectively. D-Amino acid oxidase from hog kidney was not able to catalyze cephamycin C.