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Biomedical subjects

S Fukuda

Publications and source records attributed to S Fukuda.

At least 775 records · Page 43Linked to original sources

Ultrastructural and physicochemical studies on glycogen macromolecules from ascites hepatoma AH 13 cells. A comparison with normal adult rat muscle, liver and fetal liver glycogen.

Glycogen extracted from rat ascites hepatoma AH 13 cells was compared with that from adult rat liver, adult rat muscle, and fetal rat liver 3 days before delivery, by electron microscopic, biochemical and physicochemical techniques. The ascites hepatoma AH 13 glycogen revealed two major different types of glycogen macromolecules by sucrose discontinuous density gradient centrifugation. The glycogen of the light fraction was very similar to rat muscle glycogen macromolecules in its size and shape except that it exhibited a stronger Cotton effect on measurement of the optical rotatory dispersion and circular dichroism than the muscle glycogen. Furthermore, this light material different from normal muscle glycogen. The other glycogen which also included very small amounts of irregular particles of glycogen macromolecules was contained in the heavy fraction was very similar to the adult rat liver glycogen macromolecules which did not display the Cotton effect. Electron micrographs showing the ultrastructure of the glycogen particles extracted from the AH 13 cells by negative staining revealed a variety of size and shape, and they contained two types of glycogen macromolecules with the smaller muscle types and larger adult type of liver glycogen macromolecules. The glycogen macromolecules also formed varied irregular structures in conformation.

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Effects of Mepivacaine on adrenergic neuroeffector junction of the isolated rabbit aorta.

The effect of mepivacaine on adrenergic neuroeffector junction was studied in the isolated rabbit aorta. Mepivacaine, 5 X 10(-5) to 5 X 10(-4) M, attenuated the contractile response to transmural neural stimulation, the attenuation being greater in the response at high frequency stimulations. The attenuation of the responses by mepivacaine was not prevented by prior application of cocaine. The concentration-response curve for norepinephrine was shifted to the right by mepivacaine, 5 X 10(-5) to 2 X 10(-3) M. The attenuation of the response to transmural stimulation was greater than that of the response to an equipotent concentration of exogenous norepinephrine. Pretreatment with mepivacaine, 5 X 10(-5) to 2 X 10(-3) M, protected alpha-adrenoceptors from persistent blockade by phenoxybenzamine in a dose-dependent manner. The contractile response to histamine was not significantly altered by mepivacaine in concentrations up to 5 X 10(-4) M. Mepivacaine, 5 X 10(-4) and 2 X 10(-3) M, decreased the response to high concentrations of KCl. Ca2+-induced contractions in aortic strips previously exposed to Ca2+-free media and depolarized by excess K+ were significantly inhibited by mepivacaine, 5 X 10(-4) and 2 X 10(-3) M. It may be concluded that mepivacaine causes vasodilation through an alpha-adrenoceptor antagonism in addition to a sympathetic nerve conduction blockade. High concentrations of mepivacaine appear to interfere with the transmembrane influx of calcium in the vascular smooth muscle.

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Pulmonary complications of long-term respirator care in infants.

Twelve infantile autopsy cases up to 205 days using a long-term respirator care were examined in this study. These cases could be divided into three subgroups. The first group included the cases treated with long-term respirator care for hyaline membrane disease. In this subgroup, bronchopulmonary dysplasia was found during the course. The second group included the cases treated with long-term respirator care for other causes and were very premature infants. In this group, some cases showed bronchopulmonary dysplasia-like lesions. The third group was similar to the second group except for not being very premature. All groups had similar histological changes including alveolar cell desquamation, regeneration of alveolar lining cells, fibrosis, and smooth muscle-like tissue formation of alveolar walls. However, the premature lung tissues remained characteristically in some cases of the second group. In this group, the prematurity of lung was thought responsible for the development of bronchopulmonary dysplasia-like lesion. In addition to bronchopulmonary dysplasia or bronchopulmonary dysplasia-like lesion, other changes including pneumonia, persistent ductus arteriosus, cytomegalic inclusion disease and so forth were discussed.

Bronchi↗

Radiographic studies on maturation process of secondary ossification centers in long bones of the Japanese white rabbit.

The maturation process of the secondary ossification centers of the extremities was radiographically investigated in the Japanese white rabbit of both sexes aged 1 day to 78 weeks. The ossification centers appeared at 1 day of age in the proximal and distal epiphyses of humerus, the head of femur, the distal epiphysis of femur and the proximal epiphysis of tibia, at 1 week of age in the supraglenoid tubercle of scapula, the proximal and distal epiphyses of radius, the proximal and distal epiphyses of ulna, the greater trochanter of femur, the distal epiphysis of tibia and the distal epiphysis of fibula, and at 2 weeks of age in the proximal epiphysis of fibula. The ossification centers developed rapidly from the time of appearance to 8 weeks of age, and gradually thereafter until 32 weeks of age. By 78 weeks of age, the complete fusion with the diaphysis was observed in the supraglenoid tubercle of scapula, the proximal and distal epiphyses of humerus, the head and distal epiphysis of femur. Incomplete fusion, leaving an epiphyseal line, was found in the proximal and distal epiphyses of radius, ulna, tibia and fibula, respectively.

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