PubMed Health⌕ Search

Biomedical subjects

M Kakehi

Publications and source records attributed to M Kakehi.

33 records · Page 2Linked to original sources

Afterloading technique for interstitial irradiation of lesions in deep-seated organs.

An afterloading procedure using iridium 192 seeds was developed for the control of both localized primary lesions that are difficult to remove and superficial residual lesions that remain after the partial removal of tumors in relatively inaccessible, deep-seated organs. This technique makes possible the delivery of a minimal radiation dose to lesions in deep-seated organs. Fewer complications result, the seeds can be adjusted at appropriate intervals in proportion to the amount of radioactivity desired, and radiation exposure to personnel can be reduced. This paper describes the techniques and apparatus used to place the seeds in the tubing. Primary lesions of the urinary bladder, the prostate gland, and the esophagus, residual lesions in the brain and lung, and metastases in intrapelvic lymph nodes were treated. No technical difficulties or complications were encountered. Radiation exposures to personnel were minimized. The results indicate that the procedure has practical applications.

Brachytherapy↗

Homologous maturase-like proteins are encoded within the group I introns in different mitochondrial genes specifying Yarrowia lipolytica cytochrome c oxidase subunit 3 and Saccharomyces cerevisiae apocytochrome b.

A mitochondrial cox3 gene in the alkane yeast, Yarrowia lipolytica, encodes a subunit-3 protein of cytochrome c oxidase, and contains a 1044 base-pair-long intron, as compared with the corresponding intronless gene in Saccharomyces cerevisiae. The intron belongs to a group I intron as determined by the cDNA sequence for the splicing sites as well as the predicted RNA secondary structure. Remarkably, this intron could code for a protein of 206 amino-acid residues which showed 63% similarity with an RNA maturase encoded by the second intron of the mitochondrial apocytochrome b gene in S. cerevisiae. Both introns occurred within the conserved exon sequence, 5'-TT(G/C)AGGTGC-3', suggesting the possible transposition of a common ancestral intron.

Amino Acid Sequence↗

Organization and transcription of the mitochondrial ATP synthase genes in the yeast Yarrowia lipolytica.

Mitochondrial gene organization was studied in a dimorphic yeast, Yarrowia lipoltica. The gene order in a sequenced 6.6-kilobase region closely resembles that of the human mitochondrial genome in that ATP synthase subunit 8 and 6 genes are followed by genes for cytochrome c oxidase subunit 3 (which contains an intron), NADH-ubiquinone oxidoreductase subunit 4, and ATP synthase subunit 9. This region also contains tRNA genes decoding AUA, UGA, CUN and CCN codons, suggesting a unique mitochondrial translation. All the above genes are transcribed from the same DNA strand into multigenic RNAs, starting from a nonanucleotide sequence, 5'-ATATAAATA-3', similar to other yeast mitochondrial promoters.

Amino Acid Sequence↗

Multi-institutional clinical studies on hyperthermia combined with radiotherapy or chemotherapy in advanced cancer of deep-seated organs.

Multi-institutional studies on clinical hyperthermia of deep-seated tumours were undertaken using 8 MHz radiofrequency capacitive heating devices (Thermotron RF-8) at seven institutions. Each institute was designated to treat specific organs. This paper contains the accumulations of the results obtained at different institutions charged for different tumours. Deep-seated tumours in the lung, stomach, pancreas, liver, urinary bladder and rectum were treated. A total of 177 cases examined from January 1985 to December 1988 included 96 cases (54%) treated with radiotherapy plus hyperthermia, among which 14 cases were pre-operative. Of 177 cases, 81 (46%) were treated with chemotherapy plus hyperthermia. Complete response (CR) and partial response (PR) were obtained in 80% of the cases with lung cancer, 39% with stomach cancer, 56% with liver cancer, 35% with pancreas cancer, 71% with urinary bladder cancer, 100% with primary rectal cancer, and 47% with recurrent rectal cancer. Thermometry was performed using two techniques; one is direct measurement of intratumour temperature in lung and liver cancers, the other is indirect measurement of intracavitary temperature for stomach, pancreas, urinary bladder and rectal cancers. Intratumour temperatures were measured in 30 of the 43 tumours of the lung and liver. The maximum tumour temperature was greater than 42 degrees C in 23 (77%) of the 30 tumours. Intracavitary temperatures were measured in 133 (99%) of the 134 tumours of stomach, pancreas, urinary bladder and rectum. An intracavitary temperature greater than 42 degrees C was obtained in 98 (73.7%) of the 133 tumours. The contribution of hyperthermia in improving the quality of life of patients under terminal care was also investigated. It was indicated that hyperthermia was one of the most effective treatment techniques for advanced or inoperable cases. In this study local control rate (LCR) was mainly discussed because the period of follow-up was only 3 years. Side-effects were observed in 37 cases (21%); main side-effects were fatty induration, pain during treatment and burn. However, no side-effects were severe enough to interrupt therapy.

Adult↗

Combination radiotherapy of urinary bladder carcinoma with chemohyperthermia.

The combination therapy of urinary bladder cancer with radiation and hyperthermia with bleomycin was investigated. Immediately following daily external irradiation (40 Gy/4 weeks), patients were irrigated with a solution of warmed saline (intravesical temperature, 42-43 degrees C) containing 30 micrograms/ml bleomycin. Of a total of 56 patients, complete responses were observed in 25, and partial responses in 21. Among T2-T3 cases, an 84% response rate was noted in combination therapy, whereas a 56% response rate was observed after radiation alone (50-70 Gy). The side-effects of the combination therapy were limited to reversible bladder irritation, and bladder capacity could be maintained within normal limits. These results suggest that combination therapy represents an effective conservative therapy for the management of bladder cancer.

Administration, Intravesical↗