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Biomedical subjects

K Isono

Publications and source records attributed to K Isono.

At least 433 records · Page 24Linked to original sources
PubMed1986

[Combination therapy of local administration of OK-432 and radiation on a murine fibrosarcoma (NFSa)--combination effect and histological examination].

The combined effect of radiation with local administration of OK-432 was studied using natural fibrosarcoma (NFSa) of C3H mice that are less immunogenic and resistant to radiation (TCD 50, 83, 15 Gy). When 2KE of OK-432 was administered together with 1 X 10(6) tumor cells, tumor survival was inhibited in 7/8 (87.5%) of mice. Single local administration of OK-432 (2KE, 4KE, 8KE) showed hardly any effect on tumor survival. Combined treatment of 2KE of OK-432 and 4-Gy radiation, however, not only controlled tumor growth but also eradicated 1/5 (20%) of them, compared with single application of 45-Gy radiation. OK-432 worked most effectively when administered just before or after the application of X-rays. The optimum dose of OK-432 was studied by administering 2KE, 4KE and 8KE of the agent together with the application of 55-Gy radiation. 8KE groups showed the best eradication rate but 4KE groups showed the best cure rate. Therefore, the optimum dose was considered to be between 4KE and 8KE. With regard to histological effects, both the single radiation treatment and its combined treatment with OK-432 were most effective on the 6th day. The degree of degeneration and necrosis of tumor cells together with lymphocyte exudation were much higher in the combined treatment than in single radiation application.

Animals↗
PubMed1986

[A multi-center trial of MY-1, a new biological response modifier, on the immunological parameters of postoperative gastric cancer patients].

A multi-center study was performed to clarify the immunological effects of MY-1, a new biological response modifier, on postoperative gastric cancer patients. A total of 90 patients were randomly allocated either to an MY-1 treated or an untreated group. MY-1 was given 3 times a week from the 4th postoperative day for a period of 3 weeks. Immunological parameters of the patients, such as lymphocyte subsets measured with flow cytometry using various monoclonal antibodies, blast transformation responses against PHA, ConA, and PPD, natural killer activity of peripheral lymphocytes, and skin test for MY-1 and PPD, were evaluated preoperatively, before and after MY-1 treatment. The results of the two color staining method with flow cytometry showed that the population of lymphocytes positive for both OKT8 and Leu15 antigens (suppressor cells) was statistically less, and that the population of lymphocytes positive for OKT8 and negative for Leu15 antigens (killer cells) was statistically increased in patients treated with MY-1 compared with the control group.

Adult↗
PubMed1985

Evaluation of treatment for gastric cancer with liver metastasis.

In 161 cases of gastric cancer with liver metastasis but without peritoneal dissemination, evaluations were executed to find effective treatment. The most favorable results with best prognosis were obtained in the group receiving gastrectomy + hepatectomy + chemotherapy, followed by gastrectomy + chemotherapy, and gastrectomy alone. The most unfavorable outcome was in nonresected cases. Chief chemotherapy to be used after gastrectomy was FML (5-fluorouracil (5-FU) + mitomycin C [MMC] + lentinan) continuous intra-arterial infusion. Hepatectomy was found to be effective as an active measure for tumor reduction in cases of liver metastasis so far as the metastatic lesions are only a few scattered ones in both lobes.

Adult↗
PubMed1985

Unstable mutations caused by regional tandem multiplications in the gene for ribosomal protein S4 show thermosensitivity in Escherichia coli.

The nucleotide sequence of the gene rpsD for the ribosomal protein S4 of three thermosensitive mutants of Escherichia coli K12 was determined. It was found that two of them contained regional multiplications of a nucleotide sequence within the gene rpsD. In one case, it is a duplication of a 31 nucleotide stretch and in another it is a triplication of a 41 nucleotide stretch. The thermosensitive phenotype of the two mutants is unstable and reverts at the frequency of approximately 10(-4). The revertants regain the wild-type nucleotide sequence. We postulate that the two mutant genes that contain regional multiplications possibly take an intra-strands secondary structure, which is cleaved to regenerate the wild-type sequence, probably during DNA replication.

Amino Acid Sequence↗
PubMed1985

Gene rpmF for ribosomal protein L32 and gene rimJ for a ribosomal protein acetylating enzyme are located near pyrC (23.4 min) in Escherichia coli.

An Escherichia coli mutant harbouring altered ribosomal protein L32 has been isolated and genetically characterized. The mutation leading to this alteration (rpmF) and the temperature-sensitive mutation (ts-1517) present in the same strain were found to map near pyrC (23.4 min), being cotransducible not only with pyrC but also with fabD, flaT and purB in P1 phage mediated transductions. Furthermore, we found that the gene rimJ, which encodes an enzyme that acetylates the N-terminal alanine of protein S5 and the temperature-sensitive mutation, ts-386, present in the rimJ mutant strain (Cumberlidge and Isono 1979) also mapped in this region. Thus, the order of genes is deduced to be: ts-386-pyrC-ts-1517-rimJ-flaT-fabD-rpmF-purB+ ++.

Acetyltransferases↗
PubMed1985

Cloning and nucleotide sequencing of the genes for ribosomal proteins S9 (rpsI) and L13 (rplM) of Escherichia coli.

The genes for the ribosomal proteins S9 (rpsI) and L13 (rplM) of Escherichia coli have been cloned into a lambda phage vector termed L47.1. The two genes were identified by infecting UV-light irradiated cells with the resultant phages and analyzing the protein products by two-dimensional gel electrophoresis. Suitable DNA fragments of the isolate were cloned subsequently into M13 phage vectors and their nucleotide sequence was determined by the dideoxy method. It is evident that the two genes form a transcriptional unit, the rplM gene being promoter-proximal. There is a typical signal sequence for transcriptional termination after the rpsI gene. The codon usage pattern in the two genes is similar to other ribosomal protein genes of E. coli.

Amino Acid Sequence↗
PubMed1985

Protection against suture insufficiency in ante-thoracic esophagogastrostomy.

In attempts to decrease suture insufficiency in case of ante-thoracic esophagogastrostomy, a gastric tube was so specially prepared that the short gastric vessels as well as the splenic vessels were severed very adjacent to the spleen. The anastomosis of the gastric tube thus prepared to the cervical esophagus was made using EEA-autosuture instruments. The suture insufficiency rate was thus markedly improved, with a value of approximately 10 per cent. Even cases of suture insufficiency with minor leakage, control was complete with simple pressure with gauze.

Adult↗
PubMed1985

Mechanism of action and selective toxicity of ascamycin, a nucleoside antibiotic.

An unidentified Streptomyces sp. produces two nucleoside antibiotics, ascamycin and its dealanyl derivative. In contrast to the broad antibacterial activity of dealanylascamycin against various gram-negative and gram-positive bacteria, ascamycin showed selective toxicity against Xanthomonas citri and X. oryzae. Both ascamycin and dealanylascamycin inhibited the protein synthesis of X. citri, but only dealanylascamycin inhibited that of Escherichia coli. In cell-free systems from E. coli and X. citri, both antibiotics, at ca. 0.04 micrograms/ml, inhibited the polyuridylate-directed synthesis of polyphenylalanine by ca. 50%. These data suggest that ascamycin cannot permeate the bacterial membrane. The dealanylating activity toward ascamycin was found only on the cell surface of bacteria susceptible to ascamycin. Dealanylascamycin must then have been transported into cytoplasm, where it inhibited protein synthesis.

2-Chloroadenosine↗
PubMed1985

Developmental and physiological analysis of a conditional mutation affecting photoreceptor and optic lobe development in Drosophila melanogaster.

Developmental studies have shown that elavJ1 mutants are temperature-sensitive for defects in retinula cell and optic lobe structure. Anatomical and physiological examination of mutants, shifted between permissive and restrictive temperatures, shows that the early pupal period is phenocritical for producing defects in retinula cells. Although this period precedes visible development of the rhabdomere, brief pulses to 29 degrees C during this time result in characteristic abnormalities in rhabdomere structure. These studies also show that the temperature-sensitive effects on mutant optic lobe development begin prior to the effects on the retina, suggesting that the elav product participates directly in optic lobe as well as in retinula cell development.

Animals↗
PubMed1985

Antiviral activity and its mechanism of guanine 7-N-oxide on DNA and RNA viruses derived from salmonid.

Guanine 7-N-oxide produced by Streptomyces sp. was found to inhibit in vitro the replication of herpes virus (Oncorhynchus masou virus, OMV), rhabdo virus (infectious hematopoietic necrosis virus, IHNV) and a bi-segmented double-strand virus (infectious pancreatic necrosis virus, IPNV) derived from salmonids with IC50 values of about 10 micrograms/ml, 20 micrograms/ml and 32 micrograms/ml, respectively. The agent was not toxic for the host cells (chinook salmon embryo, CHSE-214) at the IC50 concentrations. Labeling of IHNV viral RNA and host cellular DNA and RNA with [3H]uridine and [3H]thymidine during drug treatment showed that guanine 7-N-oxide did not reduce the incorporation of these precusors into RNA and DNA. The anti-IHNV activity of guanine 7-N-oxide was enhanced synergistically by neplanocin A, an inhibitor of RNA methylation. The mechanism of action of guanine 7-N-oxide is discussed, in regard to maturation of viral messenger RNA including capping.

Adenosine↗
PubMed1985

Synthesis and biological activity of nucleoside antibiotics, ascamycin and its amino acid analogs.

Synthesis of an alanylsulfamoyl nucleoside antibiotic, ascamycin was achieved by the condensation of N6-t-butyloxycarbonyl-2-chloro-9-(2',3'-O-isopropylidene-5'-O-sulfamoyl- beta-D- ribofuranosyl)adenine(3) with t-butyloxycarbonyl-L-alanylimidazole in the presence of NaH in DMF. Deprotection with 90% trifluoroacetic acid gave ascamycin in 61% overall yield. This procedure may be applicable for preparation of a number of amino acid analogs of ascamycin.

Adenosine↗
PubMed1985

Recurrence of intrathoracic esophageal cancer.

We have investigated the site of recurrence after resection of esophageal cancer in a total of 147 cases, which were examined and classified according to the site as follows: lymph nodes, organs, local sites, remnant of the esophagus, and peritoneum. The highest incidence of recurrence was 40% in both lymph nodes and organs. Recurrence was found frequently in the cervical and upper mediastinal lymph nodes. Careful examination should be made in the abdominal paraaortic lymph nodes. As for recurrence in organs, high rates were observed in lung, liver and bone; 70% of the recurrences in these organs were combined with simultaneous metastasis in other organs. In our examination of autopsied cases with local recurrence, the cancer was revealed as a tumor mass covering extensively each side of the posterior mediastinum. At the same time pleural dissemination was frequently observed. In the cases involving recurrence in the remnant esophagus, the disease-free interval was about 18 months--longer than the interval before recurrence in any other site. Peritoneal recurrence appeared in the patients with middle thoracic esophageal cancer. The prognosis following recurrence was extremely bad, with only a few exceptions: the survival period after recurrence was 8 months if it was in the lymph nodes, and an average of 4 months for other types of recurrence. The survival period was only 2 months after peritoneal recurrence.

Adult↗