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Biomedical subjects

Y Takeuchi

Publications and source records attributed to Y Takeuchi.

At least 1,063 records · Page 59Linked to original sources
PubMed1981

Dynamic states of phospholipids in Escherichia coli B membrane. Electron spin resonance studies with biosynthetically generated phospholipid spin labels.

Mobility of phospholipid hydrocarbons in the Escherichia coli B membrane fractions was studied by labeling phosphatidylethanolamine or phosphatidylglycerol in situ by biosynthetic incorporation of the spin label. For this purpose, CDP-diacylglycerol spin label was synthesized from phosphatidic acid spin label and cytidine 5'-phosphoromorpholidate and purified by thin-layer chromatography. DCP-diacylglycerol spin label was then incorporated into phospholipids biosynthetically. ESR spectra of these E. coli B membrane fractions showed that phosphatidylglycerol tended to interact with membrane proteins through the mediation of Mg2+, whereas phosphatidylethanolamine had less of this tendency and was more involved in the formation of the bulk of the bilayer continuum of the membrane. These conclusions were also supported by labeling membranes with exogenous spin-labeled phospholipids, although there was some indication that exogenous phospholipids were incorporated into sites different from the sites of incorporation of phospholipids newly synthesized in situ.

Cell Membrane↗
PubMed1981

Topographical representation of the hypoglossal nerve branches and tongue muscles in the hypoglossal nucleus of macaque monkeys.

Representation of the hypoglossal nerve branches and tongue muscles was examined in the hypoglossal nucleus of macaques by the horseradish peroxidase method. The nucleus was divided cytoarchitectonically into the medial and lateral divisions at rostral levels, and into the mediodorsal, medioventral, ventral and laterodorsal divisions at caudal levels. The medial, mediodorsal, medioventral and ventral divisions supplied the medial branch. The lateral and laterodorsal divisions supplied the lateral branch. The geniohyoid motoneurons (MN) composed the ventral division. The genioglossus MN were clustered dorsally in the medial division. The hyoglossus and styloglossus MN were located most laterally in the laterodorsal division.

Animals↗
PubMed1981

A comparative study on the toxicity of n-hexane and its isomers on the peripheral nerve.

Commercial hexane which caused polyneuropathy in many workers contained 10-40% of 2-methylpentane, 3-methylpentane and methylcyclopentane in addition to n-hexane. The hexacarbon compounds methyl n-butyl ketone, 2,5-hexanedione and etc. were shown to be neurotoxic like n-hexane. Therefore, 2-methylpentane, 3-methylpentane and methylcyclopentane which are also hexacarbon compounds were suspected to be neurotoxic, but their neurotoxicity had not been sufficiently investigated. The present experiment was performed to clarify their neurotoxicity by measuring the nerve conduction velocity in the rat's tail. Thirty rats were divided into five groups of 5-7 rats. n-Hexane, 2-methylpentane, 3-methylpentane and methylcyclopentane were diluted with olive oil and orally administered daily for eight weeks. The body weight, motor nerve conduction velocity, motor distal latency and mixed nerve conduction velocity were measured before administration, after two, four, six and eight weeks' administration. The n-hexane group showed a distinct impairment of the functional states of the peripheral nerve. Methylcyclopentane, 2-methylpentane and 3-methylpentane group had some significant differences in comparison with the control in the experiment, although these differences were not so distinct as those in n-hexane group. The results revealed that the neurotoxicity of the three chemicals was not so severe as that of n-hexane and were in the order of n-hexane greater than methylcyclopentane greater than or equal to 2-methylpentane divided by 3-methylpentane.

Animals↗
PubMed1981

Clinical performance of microporous polypropylene hollow-fiber oxygenator.

A newly developed polypropylene hollow-fiber oxygenator was used from June 1979, to July, 1980, in 100 patients undergoing open-heart operation. Adequate oxygenation and carbon dioxide elimination were observed throughout perfusion in spite of a relatively low ratio of oxygen flow to blood flow. Plasma hemoglobin level was maintained low after long hours of perfusion. There were no complications related to the oxygenator during or after the operation. Because of its highly efficient performance as well as small size and easy handling, this oxygenator is being used routinely during open-heart procedures in our hospital.

Adolescent↗
PubMed1981

An experimental study on the combined effects of n-hexane and toluene on the peripheral nerve of the rat.

An electrophysiological study was undertaken to determine whether toluene affected the neurotoxicity of n-hexane. Separate groups of eight rats were exposed to 1000 ppm n-hexane, 1000 ppm toulene, 1000 ppm n-hexane plus 1000 ppm toluene, of fresh air in an exposure chamber for 12 hours a day for 16 weeks. The body weight, MCV, DL, MNCVs were measured before exposure, after four, eight 12, and 16 weeks exposure; and four weeks after exposure was discontinued. Exposure to 1000 ppm n-hexane considerably impaired the function of the peripheral nerve, but exposure to a mixture of 1000 ppm n-hexane plus 1000 ppm toluene resulted in only slight impairment; 1000 ppm toluene had little effect. These results strongly suggest that toluene decreases the toxic effects of n-hexane on the peripheral nerve.

Animals↗
PubMed1981

Cardiac surgery of eight children with Kawasaki disease (mucocutaneous lymph node syndrome).

The coronary arterial lesions of Kawasaki disease are characterized by multiple stenoses and aneurysms, which might lead to myocardial ischemia, myocardial infarction, mitral insufficiency due to ischemic papillary muscle dysfunction, ventricular aneurysm, etc. Eight children aged 6 to 13 years with Kawasaki disease underwent surgical treatments. These were coronary bypass surgery, coronary bypass surgery combined with right coronary aneurysmectomy and coronary bypass surgery combined with left ventricular aneurysmectomy. The postoperative course was smooth in all the patients. The selective angiography performed 1 month after the operation revealed the patency rate of 85% of the bypass grafts. However, 1 patient died suddenly during strenuous exercise 3 years after the surgery. Several points to be considered in the aortocoronary bypass in the patients with Kawasaki disease are discussed. These include the unknown fate of saphenous vein grafts and the possibility of higher incidences of graft failure in the growing children. Since the long-term postoperative results are as yet not fully understood, close follow-up of the patients treated by aortocoronary bypass surgery would be mandatory.

Adolescent↗
PubMed1981

[An occupational health survey on dry cleaning workers (author's transl)].

In order ot clarify the working conditions and health of dry cleaning workers, we investigated dry cleaning workshops in C ward of Nagoya City. We had the responses from 52 (91%) workshops and 181 (97%) workers. 26 (50%) of the workshops used petroleum solvents, 23 (46%) perchloroethylene, two (4%) 1, 1, 2-trichloro-1, 2, 2-trifluoroethane (R 113), and one (2%) petroleum solvent plus perchloroethylene. Average amounts of solvents consumed per workshop were 1280 kg/year of petroleum solvents, 1450 kg/year of perchloroethylene, and 275 kg/year of R 113. Average number of workers employed in 19 workshops per workshop was 3.6 persons (median 2.0), and the remaining 33(63%) workshops had no employee. The workers complained of strange smell, irritation of eyes, unsteady feeling of head at high rate during week. They also had the high rate of complaints of shoulder stiffness, fatigability, lumbago, and the percentages of them were higher in the workers using petroleum solvents than those in the workers using perchloroethylene. More detailed surveys were made in 13 workshops out of 52. In these cases, average working hours were 11.1 per day and average years of using solvents were 12.9 in workshops using petroleum solvents, 8.4 in those using perchloroethylene including 3.1 years of petroleum solvents. Relatively high concentrations of solvents were detected under the nose of the workers pulling clothes out of dry cleaning machines, near the clothes just pulled out, and about 30 cm above the clothes at brushing with solvents before putting them into the machines. Perchloroethylene leaked from the dry cleaning machine in a workshop. Amount of the total trichlorinated compounds (TTC) in the urine of the workers directly engaged in dry cleaning with perchloroethylene tended to be larger than those of the indirect workers. TTC in both groups, however, were significantly larger than those in the control and in the workers using petroleum solvents. RBC, Hb, an Ht of the female workers in the petroleum solvents workshops were lower than those in perchloroethylene workshops. Liver function tests showed that the average values in the workers directly engaged in dry cleaning with perchloreothylene were significantly larger than those in the indirect workers. A case of malignant lymphoma, a case of liver dysfunction and a case of diabetes mellitus were found among workers directly engaged in dry cleaning. Workers in the small-sized dry cleaning workshops would not be prevented from exposure to organic solvents without the further improvement of administrative guidance and cooperation of the makers of dry cleaning machines and solvents.

Adult↗
PubMed1981

[Absorption and excretion of cefotaxime and its levels in uterine arterial blood, female internal genital organ tissue and pelvic cavity fluid (author's transl)].

Following results were obtained from intravenous single administration of cefotaxime 2 g by measuring its levels in uterine arterial blood, elbow venous blood, ovary, oviduct, several sites in uterine tissue, and in the fluid excreted in the dead space formed by radical hysterectomy. (1) Uterine artery and elbow vein blood levels revealed marked increase immediately after administration followed by gradual reduction at slow rate. (2) Peak levels in female internal genital organ tissue were achieved 12 approximately 19 minutes after cefotaxime administration, and ranged between 5 to 8 mcg/g independently from measurement site. In cervix uteri, portio vaginalis high concentration of 4.9 approximately 5.7 mcg/g was achieved within ten minutes after drug administration. (3) In the fluid excreted in the dead space formed by radical hysterectomy cefotaxime levels were maintained around 15 mcg/ml level throughout 5 approximately 6 hours following its administration, and gradually decreased at slow rate later.

Cefotaxime↗