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Biomedical subjects

I Tanaka

Publications and source records attributed to I Tanaka.

At least 415 records · Page 23Linked to original sources
PubMed1988

[Determination of the exposure concentration of propylene oxide to produce neuropathy in rats].

Although propylene oxide, which is similar in chemical structure to ethylene oxide, is expected to produce neuropathy, there is no convincing evidence of the degeneration of the peripheral nervous system. To determine the exposure concentration of propylene oxide necessary to produce neuropathy in male Wistar rats, we subjected them to repeated exposures of propylene oxide at concentrations of 500, 750, 1000, 1500 and 2000 ppm. The test rats were subjected to a single 6 hour exposure of propylene oxide at a concentration of 1500 parts per million 5 times a week for 3 weeks. They developed a significant decrease in body weight, abnormal posture of the hindlegs and axonal degeneration of myelinated fibers in the peroneal and sural nerves, the nerves to the soleus muscle, and in the fasciculus gracilis of the spinal cord. Therefore, it was concluded that propylene oxide induces neuropathy in rats characterized by axonal degeneration, similar to that produced by ethylene oxide, and that the exposure to the higher concentration of propylene oxide is more necessary to produce neuropathy than in the case of ethylene oxide neuropathy in rats.

Animals↗
PubMed1988

[Effects of repeated inhalation-exposure to fenitrothion powder on blood cholinesterase activity in rats].

Effects of repeated exposure to Fenitrothion (Sumithion) powder on erythrocyte membrane acetylcholinesterase (AChE) and plasma cholinesterase (PChE) were studied. Rats (Wistar, male) were exposed to fenitrothion powder for 2 hrs/day, 5 days/week for up to 3 months. The suppression of AChE and PChE increased as the exposure period and exposure concentration increased, although no suppression of AChE was found after a single 4-hr exposure. The persistence of AChE inhibition after the termination of exposure increased with the increase of the exposure period and was longer than that of PChE. Therefore, the AChE activity seems to be useful in examining the response to the repeated exposure to fenitrothion powder.

Administration, Inhalation↗
PubMed1988

Lung burden of green nickel oxide aerosol and histopathological findings in rats after continuous inhalation.

There are few inhalation studies of nickel carcinogenesis. In this study, Wistar male rats were exposed to green nickel oxide (NiO(G)) aerosols (mass median aerodynamic diameter, 0.6 microns) for 7 h/d, 5 d/wk for up to 12 mo. The average exposure concentration was controlled at 0.3 and 1.2 mg/m3 during the exposure. For histopathological examination and measurement of the nickel concentration in rat organs, the rats were sacrificed at 3, 6, and 12 mo of exposure and 8 mo clearance period following 12 mo of exposure. The nickel content in rat lungs that was observed up to 2.6 mg after 12 mo exposure, was proportional to the exposure concentration during the exposure. The clearance of the nickel from the lungs was very slow and the biological half time was determined 7.7 mo. Although the rats were exposed continuously to NiO(G) for 12 mo and kept for 8 mo clearance period, there were no malignant tumors in any of the exposed animals.

Aerosols↗
PubMed1988

Reconstruction of breast after super-radical mastectomy with a pedicled latissimus dorsi flap and a free TRAM flap.

Reconstruction of the breast after super-radical mastectomy is difficult because not only a breast mound but also the subclavicular and anterior axillary regions must be reconstructed simultaneously. If a defect is extremely large a single flap cannot fulfil these two purposes. For this goal we use two flaps, an ipsilateral pedicled latissimus dorsi musculocutaneous flap and a free TRAM flap pedicled on the inferior epigastric vessels. A latissimus dorsi flap along with a silicone gel prosthesis is used to reconstruct a breast mound and the free TRAM flap is transferred to augment the subclavicular and anterior axillary regions. We have used this technique successfully in three cases.

Adult↗
PubMed1988

Factor VIII polypeptide specificity of monoclonal anti-factor VIII antibodies.

Four monoclonal antibodies against factor VIII, NMC-VIII/1, NMC-VIII/2, NMC-VIII/3 and NMC-VIII/4, were produced. The first three antibodies were of the IgG1 immunoglobulin subclass, while the fourth was IgM. The affinity of each antibody for factor VIII was high and anti-factor VIII clotting activity was detected in NMC-VIII/2, NMC-VIII/3 and NMC-VIII/4. NMC-VIII/1 had no inhibitory effect on factor VIII clotting activity. Immunoblotting using purified intact and thrombin-treated factor VIII identified the antibodies' factor VIII polypeptide specificities. With thrombin-treated factor VIII the factor VIII fragments for NMC-VIII/1 and NMC-VIII/2 were 80 kDa and 54 kDa, respectively, while both NMC-VIII/3 and NMC-VIII/4 recognised a 44 kDa fragment. With intact factor VIII, antibodies NMC-VIII/2-4 bound to polypeptides larger than 90 kDa, especially NMC-VIII/2, which reacted with a chain of 330 kDa thought to be a mature form of factor VIII protein. We also detected a mature form of factor VIII in hepatic sinusoidal endothelial cells by immunoperoxidase staining. Identification of the factor VIII polypeptides bearing these fragments enabled us to clarify the localization of the factor VIII thrombin cleavage site, and suggested the existence of factor VIII in hepatic sinusoidal endothelial cells.

Animals↗
PubMed1988

[Estimation of thermal desorption efficiencies from activated carbon for determination of adsorbed organic solvents].

A method for estimating thermal desorption curves and desorption efficiencies of organic solvents from activated carbon was developed for the determination of adsorbed solvent by thermal desorption method, and the estimated values were compared with the experimental values. The Freundlich or the Langmuir isotherm was assumed in obtaining the solution. Thermal desorption experiments were conducted by the following two methods: a) Desorption of solvents which were adsorbed in the activated carbon at the desorption temperature under the nitrogen gas flow containing vapor until the system reached its equilibrium state. b) Desorption of solvents which were adsorbed in the activated carbon previously at room temperature. The model was based on a) method, but the estimated desorption curves and desorption efficiencies agree well with the experimental ones not only for a) method but also for b) method.

Acetates↗
PubMed1988

Effects of chronic inhalation of ethylene oxide on lipid peroxidation and glutathione redox cycle in rat liver.

The chronic effects of ethylene oxide (EO) on hepatic metabolism were investigated. Both reduced and oxidized forms of glutathione in liver were not changed during chronic exposure to EO for 13 weeks. On the other hand, increased levels of malondialdehyde were detected at 6 weeks and at the end of exposure periods, as compared with those of control livers. The activity of glutathione reductase was decreased at 6 and 13 weeks and therefore in inverse proportion to the lipid peroxide, although the reduced form of glutathione did not decrease probably due to the increase of de novo synthesis. These results indicate that EO treatment enhances lipid peroxidation and also affects glutathione redox cycle, but glutathione did not play a causative role in the induction of lipid peroxidation under the present conditions.

Administration, Inhalation↗
PubMed1988

[A case of secretory carcinoma of the breast in an adult].

This report describes a case of secretory carcinoma of the breast in the adult. The patient, a 56-year-old female, had a tumor, 1 cm in size, in the upper outer quadrant of her left breast, and Patey's modified radical mastectomy was performed. No nodal metastases were found. Although secretory carcinoma of the breast has been called "juvenile carcinoma", 27 adult cases have been reported previously in the English and Japanese literature. It is reported to have a good prognosis but surgical therapy with an axillary node dissection is recommended, since axillary metastases have been found in approximately 30% of the recorded cases.

Breast Neoplasms↗
PubMed1987

Particle size distributions in lungs and bronchopulmonary lymph nodes due to long-term exposure to coal fly ash aerosol in rats.

Inhalation studies were carried out with rats exposed to coal fly ash for 12 months. The main aim was to elucidate the factors that influence the accumulation of particles in the lungs during chronic exposure. Experimental results show that the particles of less than 2.3 micron can be transported to the bronchopulmonary lymph nodes by one of the clearance mechanisms.

Aerosols↗