Akihide Kitamura

Effective chemotherapy for abdominal desmoid tumor in a patient with Gardner's syndrome

Desmoid tumors are rare, but not in patients with Gardners syndrome. Although standard treatment is wide surgical excision, we prescribed chemotherapy for a 30-year-old woman with intra-abdominal desmoids, a complication after subtotal colectomy for the treatment of familial polyposis coli. Exploratory laparotomy revealed that the desmoids were not resectable. Chemotherapy with combinations of vincristine, azathioprine, cyclophosphamide, and prednisone was prescribed for over 3 months, and a partial regression of the tumors occurred. Two years after the initiation of the chemotherapy, complete regression of tumors was achieved with cyclophosphamide and prednisone. Surgical excision, irradiation, and chemotherapy treatments are discussed.

Suppression and stimulation of DNA synthesis by ADP-ribosylation of nuclear proteins from adult hen and chick embryo liver.

Abstract The stimulation of DNA synthesis by ADP-ribosylation of nuclear proteins was observed in chick embryo liver nuclei. In contrast, a significant decrease in template activity was detected in hen liver nuclei treated with NAD. When a 0.35 M NaCl extract from embryo, but not adult, liver nuclei was treated with NAD and then combined with either adult or embryo liver nuclear residue, the ability to activate the template was greatly enhanced. These results indicate that in the chick embryo liver, the ADP-ribosylation of the nuclei plays an important role as a regulator of DNA synthesis.

Possible participation of Ca2+, Mg2+-dependent endonuclease in liver DNA fragmentation after N-methyl-N-nitrosourea treatment☆

We examined the fragmentation of DNA treated with N-methyl-N-nitrosourea under conditions in which Ca2+, Mg2+-dependent endonuclease is active. The molecular mass of DNA found in mouse liver slices treated with methylnitrosurea in the presence of Ca2+ plus Mg2+ was 4 X 10(5) Da. Similar results were obtained with a reconstituted system containing partially purified Ca2+, Mg2+-dependent endonuclease and methylnitrosurea-treated DNA. The enzyme extensively cleaved methylnitrosurea-treated DNA, compared with non-treated DNA. The methylnitrosurea-treated nuclear proteins obtained from mouse liver nuclei had no effect on the DNA fragmentation by the enzyme. Using closed-circular DNA treated with methylnitrosurea, the enzyme produced single-strand cuts in the DNA, as was seen in non-treated, closed-circular DNA, however, the rate of hydrolysis was increased. Ca2+, Mg2+-dependent endonuclease thus warrants further investigation, with regard to the precise mechanism of extensive degradation of DNA in cells treated with carcinogenic alkylating agents.

“Poly (ADP-ribose) -sensitive endonuclease” and the repair of DNA damaged by N-methyl-N-nitrosourea

Abstract When rat or hen liver nuclei were incubated in the presence of N-methyl-N-nitrosourea (MNU), there was a marked stimulation of the [ 3 H] dTMP incorporation into acid-insoluble fraction. When the incubation was carried out in the presence of MNU plus NAD, the effects of MNU on the DNA synthesis were nil. Furthermore, the incubation of heat-treated nuclei with either partially purified Ca 2+ , Mg 2+ - dependent endonuclease from rat liver or Mg 2+ - dependent endonuclease from hen liver (sensitive to poly (ADP-ribose) formation), resulted in MNU-induced stimulation of the DNA synthesis. We propose that the “poly (ADP-ribose)-sensitive endonuclease” may participate in the DNA metabolism in cells exposed to DNA damaging agents.

Effect of polyamines on purified poly(ADP-ribose) synthetase from rat liver nuclei

Using the purified enzyme system, we investigated the spermine-induced stimulation of poly(ADP-ribose) formation. In the presence of 2 microgram DNA and 10 mM Mg2+ in a reaction mixture of 0.2 ml, the optimal concentrations of spermine, spermidine and putrescine were 10, 12.5 and 35 mM, respectively. With the omission of Mg2+, there was an increase in optimal concentrations of polyamines without changes in the rate of poly(ADP-ribose) formation. The concentrations of spermine required for maximum synthesis of poly(ADP-ribose) were increased in proportion to the increase in the amount of DNA. Kinetic analysis of poly(ADP-ribose) formation showed a decrease in Km values for NAD with the addition of spermine. The possible relationship of polyions with regard to DNA, spermine and histone in the purified enzyme system was discussed.

Glucocorticoid-induced reduction of poly(ADP-ribose) synthetase in nuclei from chick embryo liver

Abstract The effect of glucocorticoid hormone administration on the nuclear poly(ADP-ribose) synthetase activity of chick embryoliver was investigated. Compared with the values obtained with control nuclei, the enzyme activity was markedly reduced in the nuclei of liver prepared from chick embryo treated with 0.1 mg hydrocortisone for 12 hours or longer. The possible relationship between the reduction of poly(ADP-ribose) synthetase activity and decrease in DNA synthesis is discussed.

Theophylline reduces poly(ADP-ribose) synthetase from chick embryo liver nuclei

The effect of theophylline on poly(ADP-ribosyl)ation was investigated. The poly(ADP-ribose) synthetase activity in vitro was markedly reduced in the liver nuclei prepared from theophylline-treated chick embryo. This reduction was not due to the enzyme inhibition by theophylline contamination in the nuclear fraction. The hydroxyapatite column chromatographic analysis of [3H]adenosine-labelled poly(ADP-ribose)molecules formed in vivo revealed that the in vivo formation of poly(ADP-ribose)molecules was also decreased by theophylline administration. The theophylline-induced reduction of poly(ADP-ribose) synthesis was not due to either low NAD levels or to a decrease in the chain length of the poly(ADP-ribose) molecule, rather this reduction was derived from a decrease in the number of poly(ADP-ribose) molecule. Possible mechanisms related to reduction of poly(ADP-ribose) synthesis in vivo are discussed.

Glucocorticoid-induced changes in poly(ADP-ribose) synthetase activity from chick embryo liver

Abstract Glucocorticoid treatment produced changes in poly(ADP-ribose) synthetase activities in subcellular fractions from chick embryo liver. The reduction of poly(ADP-ribose) synthetase activity in the nuclear fraction with this hormone treatment was accompanied by a concomitant increase in the postnuclear enzyme activity, particularly in the microsomal fraction. The reduced enzyme activities found in the nuclei were restored within a few days after the injection of 10 μg hydrocortisone into the fertilized egg incubated for 11 days. However, these restorations were not observed during the period tested, when over 100 μg of the hormone was given. The changes in the poly(ADP-ribose) formation by glucocorticoid treatment were due to alteration of a number of acceptor sites, but not to chain elongation, for the molecule. With regard to decrease in the nuclear poly(ADP-ribose) synthetase activity and increase in the postnuclear enzyme activity, possible mechanisms by which glucocorticoid induces these changes are discussed.

Effect of polyanions and polycations on adenosine 3′,5′- monophosphate-binding and protein kinase activity

Abstract Histone, protamine, poly-L-arginine, and poly-L-lysine enhance the binding of adenosine 3′,5′-monophosphate (cyclic AMP) to rat liver cyclic AMP-dependent protein kinase as determined by Millipore filtration assay. Poly-L-glutamic acid and poly-L-aspartic acid suppress cyclic AMP-binding stimulated by histone. Poly-L-glutamic acid and poly-L-aspartic acid are effective against protein kinase and result in decrease in initial reaction velocity when histone is used as a protein substrate. Incubation of cyclic AMP-dependent protein kinase with 6 μg poly-L-glutamic acid produces half-maximal inhibition of cyclic AMP-dependent protein kinase when 30 μg histone is used as substrate.

Clinical significances of simultaneous determination of trypsin and amylase activities in abdominal discharge after gastrointestinal surgery.

消化器外科手術後のドレーン排液中のアミラーゼ活性は古くから縫合不全や膵液瘻の診断に用いられてきたが, 細胞障害の主役である膵プロテアーゼに関する報告は少ない.そこで腹腔ドレーン, 膵管チューブ排液および膵嚢胞穿刺液のアミラーゼおよびトリプシン活性を同時に測定し以下の結果をえた.アミラーゼ活性は上部消化管の縫合不全や膵液瘻では100 Somogyi U/dlより高値を示し100,000 Somogyi U/dl前後までの幅があった.一方トリプシン活性はErlangerらの方法で測定したが, 縫合不全では340～825U/mlであり, 膵液瘻では1.5～80U/mlであった.また純粋な膵液では1～9U/mlであった.トリプシン活性が10U/ml以下で, しかもアミラーゼ活性が100 Somogyi U/dl未満の場合は膵液の混入がないと判断してもよかった.アプロチニンの静脈内投与によりアミラーゼ活性は影響されなかったがトリプシン活性は阻害された.以上よりドレーン排液のトリプシンおよびアミラーゼ同時測定は消化器外科の術後管理に有用と思われた.