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Biomedical subjects

J Miyamoto

Publications and source records attributed to J Miyamoto.

At least 91 records · Page 5Linked to original sources

[Radiotherapy combined with pepleomycin administration for the treatment of esophageal cancer].

A combined therapy of pepleomycin (NK-613) and radiation was performed in 15 cases of esophageal and cancer. Twelve cases out of 15 were inoperable, and 3 cases were operable. NK-631 was administered by drip intravenous injection at a dose of 5 mg per day for 3 consecutive days weekly, aiming at total dose of 60-120 mg. Tumor regression rates, which were measured by planimeter on esophagogram, were 42-92% (mean 72%): two cases were more than 90%, and more than 50% in 12 cases. An average of the survival period of 15 cases was 57 weeks with 7 cases (46.7%) of 1 year survival, 2 cases (13.3%) of 2 year survival. The side effects of NK-631 observed in the present study consisted of fever 6, stomatitis 2, skin rash 2, and reversible pneumonitis 2. This study suggests that NK-631 exhibit remarkable anti-tumor effects on esophageal carcinoma, and seem to be less toxic.

Aged↗

Early cancer of the stomach treated successfully with an endoscopic neodymium-YAG laser: report of a case.

A 61-year old man with poor pulmonary function was seen with two early cancers of the stomach. Neodymium-YAG laser treatment was applied to these lesions since surgery was contraindicated. The lesions were treated four times. Both tumors completely disappeared and the patient was left with ulcer scars that formed three to seven months after the treatment. Our results suggest that endoscopic Nd-YAG laser therapy is applicable in the treatment of early gastric cancer when a surgical operation is contraindicated.

Adenocarcinoma↗

A case of multiple extra-adrenal pheochromocytomas.

A 22 year old man with two extra-adrenal pheochromocytomas located in the mediastinum and in the pelvis is presented. We believe this is the first report in Japan of extra-adrenal multiple pheochromocytomas in adult located in the two distant places.

Adult↗

Stereospecificity in toxicity of the optical isomers of EPN.

While the optical isomers of EPN were equally toxic to mice, (+)-EPN was 2.9 fold and 4.0 fold more toxic to houseflies and rice stem borer larvae, respectively, than the (-)-isomer. In addition, (-)-EPN produced paralysis of the legs in hens about 10 to 14 days after dosing, whereas (+)-EPN caused no paralytic effects. Thus, (+)-EPN appears to be a more appropriate insecticide than the racemic compound, since it combines high toxicity to insects and no delayed neruotoxicity in hens.

Animals↗

Degradation, metabolism and toxicity of synthetic pyrethroids.

Synthetic pyrethroidal compounds undergo biodegradation in mammals both oxidatively and hydrolytically, and depending on the type of compound, either of the pathways may predominate. Thus, (+) - or (+/-) -trans isomers of the chrysanthemumate ester of primary alcohols such as fenothrin, furamethrin, proparthrin, resmethrin, and tetramethrin (and possibly permethrin, too) are metabolized mainly through hydrolysis of the ester linkage, with subsequent oxidation and/or conjugation of the component alcohol and acid moieties. On the other hand, the corresponding (+)-cis enantiometers and chrysanthemumate of secondary alcohols like allethrin are resistant to hydrolytic attack, and biodegraded via oxidation at various sites of the molecule. These rapid metabolic degradations, together with the presumable incomplete absorption from the gastrointestinal tract, would generally contribute to the low acute toxicity of synthetic pyrethroids. These compounds are neither skin irritants nor skin sensitizers, and inhalation toxicity as well as dermal toxicity are fairly low. Neither is teratogenic in rats, mice, and/or rabbits or mutagenic on various bacterial strains. Subacute and chronic feeding of higher amounts of the compounds to rats invariably causes some histopathological changes in liver; however, these are neither indicative nor suggestive of tumorigenicity. Based on existing toxicological information, the present recommended use patterns might afford sufficient safety margin on human population. However, in extending usage to agricultural pest control, much more extensive investigations should be forthcoming from both chemical and biological aspects, since there is scant information on the fate of these pyrethroids in the environment. Also several of the compounds may be very toxic to certain kinds of fish and arthropods.

Administration, Oral↗

Damage and repair of rat liver DNA by simultaneous oral administration of amines and nitrite.

The effect of simultaneous oral administration of dimethylamine or aminopyrine and sodium nitrite on the damage and repair of rat liver DNA was studied by the use of centrifugation in alkaline sucrose gradient. Fragmentation of the intact DNA was observed significantly shortly after combined treatment with aminopyrine and nitrite when no liver necrosis occurred yet and the damaged DNA at the lower dosage level of aminopyrine with nitrite was found to be repaired in contrast to the increased activity of serum aminotransferase. The lowest effective dose on DNA damage at 2 hr after administration was about 40 mg/kg of aminopyrine and 80 mg/kg of sodium nitrite. This effect was equal to that caused by single oral administration of 2 to 10 mg/kg of dimethylnitrosamine, while dimethylamine at 160 or 320 mg/kg together with 80 mg/kg of sodium nitrite produced no pronounced DNA damage. The significant damage of rat liver DNA by aminopyrine and nitrite correlates well with the easier nitrosation of aminopyrine and the occurrence of high incidence of malignant liver tumors in rats fed aminopyrine together with nitrite already reported by Lijinsky.

Alanine Transaminase↗

The role of cardiac sympathetic discharges during the pulmonary depressor reflex.

The role played by the cardiac sympathetic fibers in the pulmonary depressor reflex was analyzed in twenty dogs. The selective perfusion with homologous blood of the inferior lobar vessels of the left lung with pressures of 40 to 60 mmHg decreased the spontaneous background discharges recorded from the left superior or inferior cardiac sympathetic nerves. This decrease was maximal at perfusion pressure of 80-100 mmHg. Following the decrease in the sympathetic discharges, the systolic and diastolic systemic arterial blood pressure decrease about 10 per cent. The changes were reversible when the perfusion pressure was returned to the control. The intravenous injection of atropine sulphate did not change either the systemic hypotension or the responses of the sympathetic efferent discharges induced by elevation of the pressure in the vascular bed of the lung lobe. Thus, it is believed that the systemic arterial blood pressure during this reflex may have fallen due to a diminution of the vascular tone caused by a decrease in the sympathetic efferent discharges. After transection of the vagus nerve ipsilateral to the tested lobe, the reduction of the sympathetic discharges as well as the decrease of the systemic arterial blood pressure were no longer observed. Our results further substantiate the concept that the vagus nerve is the afferent pathway for the pulmonary depressor reflex, and it may be concluded that during this reflex the sympathetic efferent activities are inhibited.

Action Potentials↗

Enzymatic hydrolysis of allergens extracted from the house dust mite, Dermatophagoides farinae.

The crude extract of the house dust mite, Dermatophagoides farinae, was subjected to enzymatic hydrolysis by the use of trypsin and pronase. The hydrolysate was fractionated by gel-filtration and ion-exchange chromatographies. Allergenic activities of the fractions were measured by Prausnitz-Küstner type skin test on guinea pig skin with homocytotropic antibodies. Major allergenic component passed through anion and cation Dowex resins but its yield was not large. On gel-filtration, the mite digest showed two major peaks of absorbance and the allergenic activity was found in the first one. This active peak was resolved into two active fractions when it was chromatographed on DEAE-Sephadex.

Allergens↗

A successful method for mass culture of the house dust mite, Dermatophagoides pteronyssinus (Troussart, 1897).

Comparative studies have been carried out to find out an optimum condition for efficient mass culture of Dermatophagoides pteronyssinus (Troussart, 1897), the most dominant species of the house dust mites. Among various food materials tested for culture media, the mixture composed of 2 parts of powdered laboratory animal food, 2 parts of dried yeast and 1 part of dried fish powder was found to be most fitted. The humidity content of the medium was best when adjusted to 16% beforehand and thin layer of the food medium was prepared in Roux's-bottle with a paper plug. The plug of the bottle was opened once a week and the medium was mixed thoroughly by shaking to prevent clotting. When about 15,000 mites were inoculated into 100 g of culture media, the highest yield was obtained with relative humidity regulated at 75% and the temperature at 25 degrees C after 12 weeks of incubation. Purified mites were separated from culture media by floatation with saturated NaCl solution and the average yield of the mice was 2 to 3 g in wet weight per 100 g of the food mixture.

Animals↗