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Biomedical subjects

M Miyoshi

Publications and source records attributed to M Miyoshi.

At least 91 records · Page 5Linked to original sources
PubMed1988

Microridges of oral mucosal epithelium in carp, Cyprinus carpio.

The surface of carp oral mucosa is characterized by various patterns of microridges about 0.3 micron wide, 0.1 micron high, and of various lengths. To elucidate the derivation and function of these microridges, the oral epithelium was examined by light- and electron microscopy. Microridges were present only on the surfaces of the superficial cells. Therefore, microridges on renewed superficial cells have been discarded, and the various patterns of microridges found on the cell surface appear to indicate the progress of their development. In thin sections, the outer leaflet of the plasma membranes of microridges stained strongly with ruthenium red, and the underlying cytoplasm was packed with many fine filaments. The superficial cells contained many secretory vesicles that were PAS-positive but Alcian blue-negative at pH 2.5 and pH 1.0. However, after sulfation the vesicles gave a positive reaction with toluidine blue. These vesicles are secreted by exocytosis at the free surface of the cells. After release, the membranes of the vesicles are thought to be utilized for formation of microridges. On the basis of these observations, the possible function of microridges is discussed.

Animals↗
PubMed1988

[Improved survival rates in Hodgkin's disease].

Results of treatment of 25 Hodgkin's disease patients at Kyushu University Hospital from 1981 to 1985 were reviewed. Total nodal irradiation or MOPP chemotherapy was used mainly. The actuarial 5-year survival rate, 87.2%, was significantly better than the 41.0% of 61 patients treated between 1966 and 1980 (P less than 0.01). However, 12 of the 24 patients in remission eventually relapsed. To further improve the survival rates of patients with Hodgkin's disease, technical improvements in total nodal irradiation and altering Adriamycin-containing chemotherapy protocol from MOPP chemotherapy are advisable.

Adult↗
PubMed1988

[Refractory anemia showing excess of blasts (BAEB) that transformed into acute myelogenous leukemia (AML-M2) with a t (?8;20) chromosomal abnormality].

In April, 1985, a 60-year-old Japanese male was diagnosed as having refractory anemia with an excess of blasts (RAEB). He thus was treated solely with blood transfusions until June, 1986, when a new diagnosis revealed that his illness had been transformed into acute myelogenous leukemia (M2). Chromosome analysis at the initial diagnosis had revealed a normal male karyotype. When the subsequent diagnosis of AML was made, however, a chromosomal abnormality [46, XY, -20, +der (20) t (?8;20) (q22;p13)] was detected. Myelodysplastic syndrome (MDS) in patients evidencing a karyotypic alteration from the initial karyotypic findings progresses in severity that includes overt leukemia, and results in a shorter survival than in patients who show no further karyotypic changes. Therefore, the prognosis of patients with MDS can be predicted more accurately by subsequently reanalyzing their chromosomes after the initial analysis, as well as by examining their peripheral blood/counts, and by monitoring bone marrow cytology.

Anemia, Refractory, with Excess of Blasts↗
PubMed1987

Purification and characterization of thymidylate synthetase from rat regenerating liver.

Thymidylate synthetase (EC 2.1.1.45) from rat regenerating liver has been purified over 5000-fold to apparent homogeneity by a procedure involving two affinity methods. Molecular weight of the native enzyme was found to be about 68,000, as determined by gel filtration. Electrophoresis in polyacrylamide gels containing sodium dodecyl sulfate yielded a single band of molecular weight of 35,000, suggesting that thymidylate synthetase is a dimer of very similar or identical subunits. The Michaelis constants for deoxyuridylate (dUMP) and (+/-)L-5,10-methylenetetrahydrofolate are 6.8 microM and 65 microM, respectively. Reaction kinetics and product inhibition studies reveal the enzymatic mechanism to be ordered sequential. 5-Fluoro-dUMP, halogenated analog of the nucleotide substrate is a competitive inhibitor of the enzyme, with an apparent Ki value of 5 nM. Amethopterin, analog of the cofactor is also a competitive inhibitor with an apparent Ki value of 23 microM.

Animals↗
PubMed1987

Effect of thyroparathyroidectomy on the activities of thymidylate synthetase and thymidine kinase during liver regeneration after partial hepatectomy.

Thyroparathyroidectomy (TPTX) carried out at 72 h before partial hepatectomy (PH) reduced the induction of hepatic thymidylate synthetase (TS) and thymidine kinase (TK), which are rate-determining enzymes in DNA synthesis, at 24 h after PH. When TPTX was carried out at 24 h before PH, TK activity at 24 h after PH was not reduced at all, yet TS activity was reduced significantly. Thus the effect of TPTX differed in time dependence between TS and TK. The depression of TK activity in rats which were subjected to TPTX at 72 h before PH, was recovered by Ca2+ supplementation. This result demonstrated that the rise of TK activity in regenerating liver is regulated by plasma Ca2+. Since a high dose of tri-iodothyronine (T3) was required to cause elevation of the activities of these enzymes and DNA content in 24 h-regenerating liver of TPTX rats, the relative contribution of T3 to liver regeneration may be small.

Animals↗
PubMed1987

Enhancement of local anaesthesia action by organic acid salts. (I): Possible change of excitability in nerve fibre membrane.

Measurements of action potentials recorded from giant nerve fibres of the crayfish abdomen showed that by addition of an organic acid salt to a local anaesthetic solution, the onset of anaesthetic action became more rapid and the duration of action was prolonged. Similar results were also obtained in rat vagal nerves. The chemical structure of compounds having these enhancing effects was found to have, in common, a carboxyl group connected with either a benzene ring or an aliphatic hydrocarbon. Topical application of anaesthetic solutions to the skin of flexor side of the forearm in humans revealed that the duration of anaesthesia evaluated by the apparent decrease of the number of pain points was significantly prolonged by the addition of salicylate. The use of local anaesthetics combined with organic acid salts would be promising in clinical practice to enhance their action greatly.

Action Potentials↗
PubMed1987

[Treatment of hepatocellular carcinoma with tumor thrombus in the main portal branch--analysis of five cases showing regression of the tumor thrombus].

Twenty-five cases of hepatocellular carcinoma with tumor thrombus in the first branch or trunk of the portal vein were treated with one-shot chemotherapy or transcatheter arterial embolization (TAE). Five of them showed regression of the tumor thrombus and survived 14 months on average. In these five cases, residual liver function was maintained at a good level. It was revealed that TAE was effective not only for tumors but also for tumor thrombi. But in cases with such tumor thrombus, normal liver tissue would be damaged by TAE. Therefore, residual liver function seems to be the most significant factor in choosing therapy.

Adult↗
PubMed1987

[The tolerance dose of the rectum].

The incidence of rectal bleeding (Grade II or III) after radiotherapy for carcinoma of uterine cervix were studied. All cases were treated by external irradiation (ERT) and intracavitary irradiation (ICR). The dosage of rectal bleeding at 5% level were as followed; 40 Gy by ERT and 27 Gy at point A by ICR in National Sapporo Hospital, 36-40 Gy by ERT and 24 Gy at point A by ICR in Aichi Cancer Center, 40 Gy by ERT and 27 Gy at point A by ICR in Kyushu Cancer Center.

Dose-Response Relationship, Radiation↗
PubMed1987

[Intraoperative radiotherapy].

Intraoperative radiotherapy, which delivers a large single dose of electrons to a tumor intraoperatively, is applied for locally advanced and/or difficult to cure malignancies which are rather difficult to treat by conventional external beams. Although this method was initially developed in Japan, increasing numbers of institutes have recently been working with IORT on a world-wide basis because of the increased availability of medical accelerators and the better results obtained. The malignancies for which IORT is indicated are cancers of the stomach, liver, biliary tract, pancreas, colo-rectum, urinary bladder, prostate and uterus, which are surrounded by normal tissues or organs with low tolerance doses, and also recurrent or difficult to cure malignancies of the brain, lung, mediastinum, bone and soft tissues are becoming candidates for IORT treatment.

Female↗
PubMed1987

[Rib fracture after postoperative tangential irradiation in breast cancer].

Incidence of rib fracture was analyzed for 118 postoperated breast cancer patients who were tangentially irradiated at the Department of Radiology, Kyushu University, from 1961 to 1976 and followed more than 5 years. Rib fracture was observed in 5% and 50% of cases treated with total radiation doses of 32.5 Gy and 52.5 Gy respectively.

Actuarial Analysis↗
PubMed1987

[Skin damage after postoperative tangential irradiation in breast cancer].

Incidence of telangiectasia and ulcer among 118 postoperated breast cancer patients, who were tangentially irradiated at Department of Radiology, Kyushu University from 1961 to 1980, followed more than 5 years were evaluated. Telangiectasia occurred in 5% at 20-35 Gy, in 50% at 50-55 Gy. Ulcer occurred in 5% at 50-55 Gy, in 50% at 70-75 Gy. Skin tolerance dose in Rubin's Table (1972) is correct.

Actuarial Analysis↗
PubMed1987

[Pulmonary fibrosis after postoperative tangential irradiation in breast cancer].

Incidence rate of pulmonary fibrosis with elevation of diaphragma was calculated for 118 postoperated breast cancer patients who were tangentially irradiated at the Department of Radiology Kyushu University from 1961 to 1980 and followed more than 5 years. 5%, 50% occurred at 40-45 Gy, 60-65 Gy, Rubin's Table (1972) is possible correct.

Actuarial Analysis↗
PubMed1987

[Factors influencing the response of normal tissue to radiation].

The dose modifying effects of the age, anatomic location of the normal tissue, positioning of animal during irradiation, preliminary treatment, number of fractions and time interval between doses on response of the normal tissues to radiation were studied, using various kinds of response of mouse hind legs such as early skin reaction, epilation, skin contraction, ulcer formation, leg contraction and growth retardation of femur. The dose modifying factors varied with the kinds and the levels of injuries, meaning that it is very important to define what the critical normal tissue is and its end point first of all, when we discuss the dose modifying factors with respect to the therapeutic gain factors.

Alopecia↗
PubMed1987

[Brachytherapy--carcinoma of the tongue].

In a review of 193 patients with carcinoma of the tongue who underwent interstitial radiotherapy in our hospital from November 1978 to 1986, 5 year actuarial local control rate were 97%, 87%, 58% and 77% for T1, T2, T3 and T4 respectively. Mucosal ulcers with tissue defects and bone exposure of the mandible occurred in 5 years after the treatments, 6%, 22%, 44%, and 100% for T1, T2, T3 and T4, respectively. Therapeutic ratio was 1 in patients with T1 who underwent interstitial radiotherapy (70 Gy/7 days) alone while it was less than 1 in those with T2 or more. Therapeutic gain factor was less than 1 in patients with combined external radiotherapy.

Adult↗