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Biomedical subjects

T Uchida

Publications and source records attributed to T Uchida.

At least 19 recordsLinked to original sources

[Leukokinetics].

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Cell Separation

Effects of periodic saccades on the body sway in human subjects.

The body sway in upright standing was decreased by periodic saccades. The decrease was also observed during voluntary rapid eye movements in complete darkness, indicating that the visual information was not concerned with the decrease of the sway. Continuous eye rotations did not affect the body sway, showing that the repetitive activation of eye muscle proprioceptors was not the cause of the sway reduction. These results suggest that some information related to the execution of saccades may affect the spinal motor system and cause the stabilization of the standing posture.

Adult

Reconstitution of lipid vesicles associated with HVJ (Sendai virus) sikes. Purification and some properties of vesicles containing nontoxic fragment A of diphtheria toxin.

A mixture of HVJ (Sendai virus) spike proteins, the nontoxic fragment A of diphtheria toxin, lecithin, and cholesterol was solubilized in sucrose solution containing a nonionic neutral detergent. The liposomal vesicles which formed on removal of the detergent by dialysis were purified by gel filtration and centrifugation on a sucrose gradient. The resulting purified vesicles had hemagglutinating activity, hemolytic activity and, after solubilization, the enzymic activity of fragment A. The vesicles had no cell fusion activity. Electron microscopy showed that both the outside and inside of membranes of the vesicles were associated with the spikes. When the vesicles were freeze-fractured, no large aggregates of particles were seen on either face. Such fragment A-containing lipid vesicles (liposomes) with HVJ spikes bound to mamalian cell membrane and released their fragment A into the cytoplasm causing cell death. Neither fragment A-containing liposomes without spikes nor empty liposomes with spikes were toxic.

Cell Fusion

Establishment of a new human chondrosarcomatous cell line.

A new cultured cell line (HuOS) was established from tumor cells obtained from the pulmonary metastatic foci of a patient diagnosed as chondroblastic osteosarcoma. The tumor cell line was maintained for over 19 months, and morphological and biological characteristics were studied. These cells retained their malignant properties and produced nodules when transferred intramuscularly to nude mice. Morphologically, these nodules revealed a chondromatous pattern.

Adolescent

Isolation of a cured strain from Corynebacterium diphtheriae PW8.

A nonlysogenic, non-toxinogenic strain was isolated from the PW8 strain of C. diphtheriae by two-step ultraviolet induction. This strain was lysed by phages derived from the PW8 strain but not by beta phages from the C7(beta) strain. When this cured strain was lysogenized with phages from the PW8 strain, toxin production by the resulting lysogens was about a half or a quarter of that of the parent strain PW8.

Bacteriophages

Frozen ultrathin-sections for x-ray microanalysis of rat tooth germs.

In order to detect the precise location and pathways of calcium in the ameloblastic layer with EM and EDX, frozen ultrathin-sections, potassium pyroantimonate (PPA) method and 45Ca-autoradiography (A.R) were employed. A population of dense granules containing Ca and P was mainly observed within the nuclei and mitochondria of the frozen-sectioned ameloblasts, whereas PPA-reaction was seen not only within them but in ER, Golgi vesicles and intercellular spaces. No granules were found at the enamel matrix by both methods, but peaks for Ca and P were distinct. Silver grains of 45Ca-A.R were located in nuclei, mitochondria. Golgi complex and intercellular spaces. These results indicate that calcium can transport across the ameloblastic layer through two main pathways, extracellular and transcellular.

Ameloblasts

Shortened platelet survival in acute promyelocytic leukemia.

A platelet kinetic study in 2 patients with acute promyelocytic leukemia (APL) associated with disseminated intravascular coagulation (DIC) demonstrated that the platelet survival was characteristically shortened. These findings suggest increased platelet consumption during the process of DIC in APL.

Blood Platelets

[Accumulation mechanism of 111In in malignant tumor (author's transl)].

In order to clarify the accumulation mechanism of 111In in maligant tumor, subcellular distribution of 111In was quantitatively determined. Buffalo rats bearing Morris hepatoma 7316A were injected intraperitoneally 111In-chloride and tumor tissues were removed 24 hours later. Subcellular fractionation of tumor tissues were carried out according to the method of C. de Duve, et al. and radioactivity of each fraction was counted. Most of the total radioactivity was distributed among the soluble, nuclear and lysosomal fractions. On account of its low protein content, the relative specific radioactivity was the highest in the lysosomal fraction. The lysosomal fraction was solubilized gradually and the resultant stepwise release of 111In and acid phosphatase activity were measured. There was a close relationship between them. From these results it was concluded that 111In accumulated especially in the lysosomes. In the electron micrography the tumor lysosomes had already engulfed many foreign materials, so that the lysosomal function would be depressed.

Acid Phosphatase