Search PubMed⌕ Search

Biomedical subjects

A Murakami

Publications and source records attributed to A Murakami.

At least 361 records · Page 20Linked to original sources
PubMed1987

[Clinico-pathological analysis of stage IIIa carcinoma of the cervix uteri].

We have reviewed cervical carcinoma IIIa cases treated at the University of Hirosaki Hospital from 1970 to 1984 and at the Metropolitan Komagome Hospital from 1975 to 1984. In this period, 32 cases were staged at IIIa, and this group accounts for less than 2% of all cervical cancer cases at these two institutions. The age of the 32 patients ranged from 33 to 86 years with a mean age of 66. In treatment methods, 3 cases were operated on and other cases were irradiated by a combination of intracavitary therapy and external beam therapy. The actuarial 5-year survival rate was 78.3%, and the relative 5-year survival rate was 86%. Our results suggest that FIGO stage IIIa carcinoma of the cervix has a much better prognosis than FIGO stage IIIb cervical cancer.

Adult↗
PubMed1986

Solid-phase syntheses of oligodeoxyribonucleoside methylphosphonates.

Oligodeoxyribonucleoside methylphosphonates of defined sequence of the type d-Np(NP)nN, where n is 6-13, are readily prepared on insoluble polystyrene supports by use of protected 5'-(dimethoxytrityl)deoxyribonucleoside 3'-(methylphosphonic imidazolides) as synthetic intermediates. The imidazolides are prepared in situ by reaction of protected 5'-(dimethoxytrityl)deoxyribonucleoside with methylphosphonic bis(imidazolide) and can be stores in the reaction solution for up to 2 weeks at 4 degrees C with no loss in activity. The condensation reaction is accelerated by the presence of tetrazole, which appears to act as an acid catalyst. The half-life for dimer formation on the polystyrene support is 5 min, and the reaction is 95% complete after 60 min. Although similar kinetics are observed when controlled pore glass is used as the support, the extent of the reaction does not go beyond 78%, even after prolonged incubation. In order to simplify purification and sequence analysis of the oligomer, the 5'-terminal nucleoside unit is linked via a phosphodiester bond. This linkage may be introduced by either an o-chlorophenyl phosphotriester method or a cyanoethyl phosphoramidite method. The latter procedure simplifies the deprotection step, since the cyanoethyl group is readily cleaved by ethylenediamine, which also removes the base protecting groups and cleaves the oligomer from the support. The singly charged oligomers are easily purified by affinity chromatography on DEAE-cellulose. The chain lengths of the oligomers were confirmed after 5'-end labeling with polynucleotide kinase by partial hydrolysis of the methylphosphonate linkages with 1 M aqueous piperidine followed by polyacrylamide gel electrophoresis of the hydrolysate.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1986

Does preoperative radiation for thoracic esophageal cancer promote intramural lymphatic invasion?

Between 1976 and 1983, 43 patients with carcinoma of the thoracic esophagus underwent esophagectomy in the Department of Surgery, Tottori University. Of these 43, 22 received a total dose of 30 to 40 Gy of Co60 (2 Gy/day) preoperatively: 21 were not given preoperative irradiation treatments. The spread of intramural lymphatic cancer invasion into the esophageal wall was compared in these two groups. The preoperatively irradiated patients manifested a significantly lower rate of lymphatic cancer invasion and the depth of invasion tended to be less than in the non-irradiated patients. However, in preoperatively irradiated subjects, the horizontal cancer spread into the extra-radiation field anal to the cancer site was greater than in the other group. In addition, a significantly higher intra-abdominal lymph node metastasis rate was found in the irradiated group than in the non-irradiated group. Our findings suggest that patients with thoracic esophageal cancer who are treated with preoperative radiotherapy must be carefully monitored for the occurrence of intramural lymphatic cancer invasion and distant lymph node metastasis.

Carcinoma, Squamous Cell↗
PubMed1986

[Clinical results and problems of total-body hyperthermia].

The clinical results and problems of extracorporeally-induced total-body hyperthermia (TBHT) for recurrent cancer were presented. A total of 105 hyperthermic treatments were performed in 38 patients who had had unsuccessful conventional systemic anticancer chemotherapy. Partial response was observed in 10 of 29 evaluable patients (37%). In analysing the anticancer effects of TBHT according to cancer site, a high efficacy was observed in patients with their main tumor in the lung, liver and lymph nodes. The anticancer effects were most enhanced when TBHT was performed in combination with cis-diamminedichloroplatinum (II) and 5-fluorouracil. In order to augment the anticancer effects of TBHT, the choice of combined agent(s) and administration timing are important. A useful method for determining the thermochemosensitivity of individual cancer cells to agents selected for drug treatment is the human tumor stem cell assay. Further, the usefulness of angiotensin II-induced hypertensive chemotherapy during TBHT for augmenting selective drug delivery to cancer tissues is stressed.

Humans↗
PubMed1985

Inhibition of rabbit globin mRNA translation by sequence-specific oligodeoxyribonucleotides.

Oligodeoxyribonucleotides 8-12 nucleotides in length whose sequences are complementary to the 5' end, the initiation codon regions, or the coding regions of rabbit globin mRNA were tested for their ability to inhibit translation in a rabbit reticulocyte lysate and in a wheat germ extract. The oligomers interact specifically with their target mRNAs as shown by their ability to serve as primers with reverse transcriptase. In the reticulocyte lysate, oligomers complementary to the 5' end or the initiation codon regions inhibit translation of both alpha- and beta-globin mRNA, whereas oligomers complementary to the coding regions have little or no effect. This suggests that reticulocyte ribosomes are able to displace the oligomers from the mRNA during the elongation but not the initiation step of translation. In the wheat germ system, translation was effectively inhibited by all oligomers regardless of their binding site on the message. In contrast to their behavior in the reticulocyte system, the oligomers inhibited alpha- and beta-globin synthesis in a specific manner. This observation suggests that control of alpha- and beta-globin mRNA translation is coordinated in the reticulocyte lysate system but not in the wheat germ extract. The results of our studies indicate that oligodeoxyribonucleotides may be useful probes for studying control of mRNA translation in cell-free systems.

Animals↗
PubMed1985

Hybridization arrest of globin synthesis in rabbit reticulocyte lysates and cells by oligodeoxyribonucleoside methylphosphonates.

Oligodeoxyribonucleoside methylphosphonates which are complementary to the 5' end, the initiation codon regions, or the coding regions of rabbit globin mRNA were synthesized. These oligomers were shown to interact with their complementary mRNA binding sites by their ability to serve as primers for reverse transcriptase. In several cases, the priming efficiency of the oligomers was enhanced when the oligomer was preannealed with the mRNA. This behavior correlates with the predicted secondary structure of the mRNA and suggests that some oligomer binding sites occur in hydrogen-bonded stem regions of the mRNA. Methylphosphonate oligomers inhibit translation of globin mRNA in reticulocyte lysates. Inhibition is due to the interaction of the oligomers with mRNA. The extent of inhibition is affected by the sequence and chain length of the oligomer, the location of the oligomer binding site on the mRNA, and the secondary structure of the binding site. Oligomers which bind to the 5' end and initiation codon regions of beta-globin mRNA inhibit both alpha- and beta-globin synthesis whereas oligomers which bind to the coding region of alpha-globin mRNA or the coding region of beta-globin mRNA inhibit translation of their target mRNA in a specific manner. Oligodeoxyribonucleoside methylphosphonates inhibit globin synthesis in rabbit reticulocytes. The effects of various oligomers on cellular globin synthesis are similar to those in the lysate system and suggest that the conformation of globin mRNA is the same in both systems during translation.

Animals↗
PubMed1985

Characterization of sequence-specific oligodeoxyribonucleoside methylphosphonates and their interaction with rabbit globin mRNA.

Oligodeoxynucleoside methylphosphonates, nucleic acid analogues that contain nonionic, 3'-5'-linked methylphosphonate internucleotide bonds, can be used to control mRNA function in living cells. In order to use analogues of defined sequence in biochemical and biological experiments, methods have been developed to characterize the chain length and sequence of oligodeoxyribonucleoside methylphosphonates and to study their interaction with mRNA. Methylphosphonate oligomers that terminate at the 5' end with a 3'-5' internucleotide phosphodiester bond are readily phosphorylated by polynucleotide kinase. Treatment of these 32P end labeled oligomers with aqueous piperidine randomly hydrolyzes the methylphosphonate linkage and upon gel electrophoresis produces a ladder of oligomers, which allows the chain length of the oligomer to be determined. The sequence of 32P end labeled oligonucleoside methylphosphonates can be determined by a modified chemical sequencing procedure. The interaction of the oligomers with rabbit globin mRNA was studied. The oligomers hybridize with mRNA in agarose gels. The stability of the hybrids increases with increasing chain length of the oligomer. The binding site of the oligomers on mRNA can be determined by using the oligomer as a primer for reverse transcriptase. The length of the resulting transcript is determined by polyacrylamide gel electrophoresis after removal of the methylphosphonate primer by treatment with piperidine. The results indicate that binding and priming ability of the oligonucleoside methylphosphonates are affected by the secondary structure of the mRNA.

Animals↗
PubMed1985

Intra-hepato-arterial infusions of cis-diamminedichloroplatinum (II) and 5-fluorouracil clinically effective for malignant liver tumors.

Four hepatocellular cancer patients and 11 metastatic liver cancer patients were treated with intra-hepato-arterial infusions of cis-diamminedichloroplatinum (II) plus 5-fluorouracil. Cis-diamminedichloroplatinum (II) (25-35 mg/m2) was given once a week, 5-fluorouracil (150-180 mg/m2) was infused daily. A partial response was obtained in 3 of 4 patients with primary cancer and in 5 of 9 evaluable metastatic cancer patients; the mean response durations were 27+ weeks in the former and 47+ weeks in the latter. However, severe bone marrow suppression occurred in 4 patients; 3 died of septicemia (2 cases) and massive intra-tracheal bleeding, respectively. This combined intra-hepato-arterial chemotherapy exerts a synergistic anticancer effect on malignant liver tumors, however, the related bone marrow suppression remains to be overcome.

Adult↗
PubMed1985

A low potential iron-sulfur cluster bound to membranes in blue-green algae.

A new low temperature EPR signal at g = 1.92 was found in photoreduced membrane fractions prepared from blue-green algae, Nostoc muscorum, Tolypothrix tenuis, Phormidium persicinum, and Anabaena variabilis. The signal also appeared when the sample was chemically reduced in the dark. Judging from the spectrum, the signal was probably due to the reduced form of a membrane-bound iron-sulfur cluster, tentatively designated as Cluster D. The midpoint potential of Cluster D was determined to be -0.27 volts. Possible roles of the cluster in electron transfer systems are also discussed.

Cell Membrane↗