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K Ebihara

Publications and source records attributed to K Ebihara.

72 records · Page 4Linked to original sources
PubMed1987

[Antitumor activity of peplomycin against 7,12-dimethylbenz(a)anthracene-induced rat mammary tumors].

Antitumor activity of peplomycin (PEP) against 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumors was compared with activities of bleomycin (BLM) and doxorubicin (adriamycin, ADM). Drugs were administered subcutaneously 3 times weekly (24 times in total) starting on 75 days after an intravenous administration of DMBA. PEP strongly inhibited the growth of mammary tumors detected at the start of the treatment, and some of the tumors disappeared and regressed upon the administration of PEP. The number of stable tumors was larger and the number of progressed tumors smaller in the PEP-treated group than in the control group. Moreover, PEP exhibited strong growth inhibitory effect with slight delay of tumor appearance against mammary tumors appeared during the treatment period. These antitumor effects of PEP were greater than those of BLM, a parent compound of PEP, and almost comparable to those of ADM.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1986

The effect of ubenimex on N-methyl-N'-nitro-N-nitrosoguanidine-induced stomach tumor in rats.

The effect of ubenimex on the progression of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced stomach tumor in rats was studied. Tumor induction was performed by giving MNNG via drinking water for 34 weeks. Ubenimex was ip administered twice a week at 0.5 mg/kg for 84 weeks in one group and 49 weeks in another starting from the first and 36th weeks after initiation of MNNG administration, respectively. The stomachs were endoscopically examined 2 times. At the 64th week after initiation of MNNG administration tumorous lesions were observed with about 70% of the rats in both ubenimex administration groups. In the ubenimex non-administration group nearly 90% of the rats had the lesions. After completion of ubenimex administration almost all the rats had the lesions in the three groups but the sizes were much smaller with the two ubenimex administration groups. Almost all of these lesions were histopathologically identified as tumorous. The tumor volume per rat in the two ubenimex administration groups from the 1 and 36th weeks was 21.0 and 19.2% of the volume in the control group, respectively. Tumor number per rat was similar among the three groups. The natural killer activity of rats was also examined after completion of the above experiment. The activity markedly increased when ubenimex was administered from the 36th week after initiation of MNNG administration. When ubenimex was administered from the first week, the activity did not increase demonstratively. From all the results described above we conclude that ubenimex exerts an inhibitory action against the progression of MNNG-induced stomach tumor in rats. Contribution of the increase of natural killer activity to ubenimex antitumor action may be dependent on schedule of ubenimex administration.

Animals↗
PubMed1984

Protective effect of biological response modifiers on murine cytomegalovirus infection.

Pretreatment with two biological response modifiers (BRM), OK-432 and PS-K, protected mice from lethal infection by murine cytomegalovirus (MCMV). This was evidenced by an increase in 50% lethal doses and a decrease in titers of infectious viruses replicated in the liver and spleen. Spleen cells from the BRM-treated mice augmented the natural killer (NK) cell activity and suppressed the replication of MCMV in vitro. During MCMV infection, the NK cell activity of the spleen cells was maintained at a high level in the BRM-treated mice, whereas it was severely impaired in untreated mice. The BRM-induced protection was nullified by concomitant administration of antiasialo GM1 antibody. Interferon was neither induced by BRM treatment nor enhanced in BRM-pretreated and MCMV-infected mice. Thus, the protective effect of OK-432 and PS-K seems to be based on activation of NK cells and prevention of MCMV-induced inhibition of the NK cell activity.

Animals↗
PubMed1984

[Case report of a non-seminomatous testicular neoplasm indicating marked efficacy of a combination chemotherapy of VBL, ACTD, BLM, CDDP and EX (VAB-4 combination therapy)].

The patient was a 29 years old male. He was attended to our hospital with a chief complaint of a right scrotal mass on August 20, 1983. Based on the diagnosis of testicular neoplasm, orchiectomy was performed on September 7, 1983. After surgery, the patients, HCG and alpha-fetoprotein (AFP) values of still remained high. Pathological diagnosis was mixed tumor (choriocarcinoma, Embryonal carcinoma, and malignant cystic teratoma). From September 22, VAB-4 combination therapy was performed and complete remission was obtained without severe side effects. The patient was in good health with normal HCG and AFP values on January 20, 1984.

Adult↗
PubMed1982

[Antitumor activity of cis-dichlorodiammineplatinum(II) and its effect on cell cycle progression].

Antitumor activity of cis-dichlorodiammineplatinum(II) (cisplatin) on various mouse transplantable tumors was investigated. Cisplatin was active against a wide variety of the following tumor systems: L1210 leukemia, P388 leukemia, B16 melanoma, colon tumor 38, Ehrlich ascites and solid carcinoma, WHT squamous cell carcinoma, and human stomach cancer G/S heterotransplanted in nude mice. From the comparison of growth inhibitory effect by cisplatin with various other antitumor agents in cultured Ehrlich ascites carcinoma cells, cisplatin was found to be mainly a concentration depending drug, but also time depending, so that it was identified as a type Ib class drug proposed by Shimoyama. Effect of cisplatin on the cell cycle progression of Ehrlich ascites carcinoma cells in mice was studied by flow cytometry of DNA. At an early stage after administration of cisplatin, cell cycle progression was delayed in S phase and blocked in G2 phase. With the elapse of time block in G1 phase or G1-S boundary was observed and the cell population, partially synchronized in G1 phase or G1-S boundary, progressed slowly through S phase to be blocked in G2 phase finally.

Animals↗
PubMed1980

Quantitative analysis of cholesterol in foods by gas-liquid chromatography.

In order to develop a simple and exact analytical method for cholesterol determination in foods by gas-liquid chromatography, several experiments were carried out in collaboration with several universities and institutes. For the extraction of lipids from foods, it was decided that chloroform-methanol (2:1) extraction was the most suitable procedure. Since pretreatment procedures using methods such as thin-layer chromatography and florisil column chromatography to purify the unsaponifiable matters reduced the recovery of cholesterol, and good results were obtained without applying the pretreatment, these procedures were concluded to be unnecessary. Gas chromatograms obtained with free sterol showed results similar to those of the trimethylsilyl ether derivative and acetate. 5-alpha-Cholestane is used as a good internal standard.

Chloroform↗
PubMed1979

Effect of dietary mineral composition on nutritional equivalency of amino acid mixtures and casein in rats.

The effect of dietary mineral composition on the quality of amino acid mixtures and intact casein was examined in growing rats fed for 28 days under "conventional" conditions. When 25% demineralized casein (DC) was the sole dietary protein source, the widely-used mineral mixture by Harper (MMH) supported growth poorly (3.2 g/day), but a new formula mineral mixture (MM2) containing sufficient amounts of zinc gave a growth rate of over 8 g/day for 21 days. With a crude casein (CC) diet, rats grew at the same rate regardless of mineral mixtures. The growth-supporting power of amino acid mixtures, one of which simulated casein (AA-A) and another patterned after Rogers and Harper to give maximal growth of rats (AA-B), was compared with those of DC and CC with addition of MMH or MM2. When the protein source was DC, AA-A or AA-B, MM2 significantly improved the growth over that of rats fed MMH. The growth-stimulating effect of MM2 was greater when added to DC diet than when added to AA-A diet. When MM2 was added to AA-B diet, the growth rate greatly increased and reached that of rats fed DC diet containing MM2 (over 8 g/day), showing a nutritional equivalency between the amino acid mixture and intact protein. Drawbacks inherent in MMH did not appear with CC diet, because CC contained considerable amounts of zinc. When a highly purified amino acid-sucrose diet is used, dietary minerals become most limiting for growth even under conventional conditions. Thus, the previous conflicting results concerning nutritional equivalency of amino acid mixtures and protein can be explained by inadequate mineral sources.

Amino Acids↗
PubMed1979

Effects of antiprostatic agents on 5alpha-dihydrotestosterone binding to rat hypophyseal and hypothalamic cytosol macromolecules.

The binding of 5alpha-dihydrotestosterone to the hypophyseal and hypothalamic cytosol macromolecules prepared from castrated male rats was observed. The effects of antiprostatic agents on 5alpha-dihydrotestosterone binding to both hypophyseal and hypothalamic cytosol macromolecules was examined. Cyproterone acetate and chlormadionone acetate showed the significant inhibiting effects on 5alpha-dihydrotestosterone binding to 7-8 S macromolecules of cytosol from both hypophysis and hypothalamus. SCH 13521 and AA 560 did also affect 5alpha-dihydrotestosterone binding to 7-8 S macromolecules of cytosol from both tissues.

Androgen Antagonists↗
PubMed1978

[Toxicological studies of pepleomycin sulfate. V. Short term intermittent toxicity in dogs (author's transl)].

The comparative studies in the short term intermittent toxicity of pepleomycin (NK631) and bleomycin (BLM) were performed on 10 beagle dogs of 13 approximately 15 months old. Two dogs per group were injected intravenously with NK631 and BLM in doses 5.0 and 2.5 mg/kg body weight every fourth day for 11 treatment. Two dogs served as control and were injected with saline solution. In the group of 5.0 mg/kg of NK631, one dog was sacrificed on day 37 of the treatment and another one dog died on day 33 of the treatment. All the dogs of other group survived until the end of the treatment. The toxicity to the hepatic and renal damage caused by NK631 was stronger than the BLM. On the contrary, the toxicity to lung and various mucocutaneous regions was weaker than the BLM. The grade of pulmonary fibrosis of NK631 was about 1/2 and 2/3 of the BLM in dose of 5 mg/kg and 2.5 mg/kg, respectively. Other toxicological changes such as anorexia and weight loss were almost similar to the BLM.

Animals↗
PubMed1978

[Studies on antitumor activities and pulmonary toxicity of pepleomycin sulfate (NK631) (author's transl)].

The antimicrobial and antitumor activities, and the pulmonary toxicity of pepleomycin (NK631) were studied in comparison with bleomycin (BLM). NK631 showed a broad antimicrobial spectrum against gram positive and gram negative bacteria equally to BLM, and its activity was about twice higher than BLM. NK631 showed higher activity on cultured HeLa S3 cells and higher antitumor effect on the transplanted tumors of Ehrlich solid carcinoma in mice, AH66 and AH66F ascites hepatoma in rats, and lower antitumor effect on Ehrlich ascites carcinoma in mice than BLM. Similarly to BLM, NK631 did not show satisfactory activity on L1210 leukemia in mice. NK631 showed marked effect on chemically induced squamous cell carcinoma, spontaneous lymph sarcoma of a dog, human and dog gastric cancer heterotransplanted in nude mice equally to BLM. Furthermore NK631 exhibited remarkably higher antitumor activity on lymph node metastasis of AH66 ascites hepatoma of rats and chemically induced gastric carcinoma of rats than BLM. Pulmonary toxicity of NK631 was low as 1/3 in incidence and 1/4 in grade of the BLM in old mice system. This trend was confirmed by chemical analysis of hydroxyproline in lung.

Animals↗
PubMed1978

[Studies on organ distribution, absorption and excretion of pepleomycin sulfate (NK631) (author's transl)].

1. Organ distribution of pepleomycin (NK631) in mice and rats was studied. NK631 was found at higher levels than bleomycin (BLM) in skin, lung, stomach, solid tumor, etc. in mice and rats. Furthermore NK631 was detected in the mesenteric and lumbar lymph node, esophagus and prostate in rats and also distributed at about twice as high levels as BLM in the AH109A hepatoma cell-metastasized lymph nodes. 2. For the elucidation of reason on low pulmonary toxicity of NK631 which is in spite of 1.5 times highly distribution in lung compared with BLM, inactivation of various BLMs by high molecular fraction of lung of mice and rats was determined. The order of inactivation rate of various BLMs in lung was as follows: BLM-M5196 greater than NK631 greater than BLM greater than BLM-HPE. There is an encouraging coincidence between index of pulmonary fibrosis in mice and inactivating rate in lung. 3. A comparative study on the serum level and urinary excretion of NK631 and BLM was performed in dogs. The blood level and urinary excretion rate of both drugs were almost similar. 4. The blood levels of NK631 were comparable to those of BLM in cancer patients.

Absorption↗
PubMedDate not supplied

Regulation of translation termination: conserved structural motifs in bacterial and eukaryotic polypeptide release factors.

Translation termination requires codon-dependent polypeptide release factors. The mechanism of stop codon recognition by release factors is unknown and holds considerable interest since it entails protein-RNA recognition rather than the well-understood mRNA-tRNA interaction in codon-anticodon pairing. Bacteria have two codon-specific release factors and our picture of prokaryotic translation is changing because a third factor, which stimulates the other two, has now been found. Moreover, a highly conserved eukaryotic protein family possessing properties of polypeptide release factor has now been sought. This review summarizes our current understanding of the structural and functional organization of release factors as well as our recent findings of highly conserved structural motifs in bacterial and eukaryotic polypeptide release factors.

Amino Acid Sequence↗