Biomedical subjects
Publications and source records attributed to N Tsuda.
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Ultrastructural and morphometrical studies were conducted on vascular tissue from 205 human Japanese specimens ranging in age from 15 weeks' gestation to 90 years. Comparison of aorta size with overall body length by allometry revealed that the aging aorta has growth and involution stages comparable to other organs, and that progressive increase in aortic diameter was the major involutional change. The cellular and extracellular components of the medial sections of thoracic and abdominal aorta, renal artery, and superior mesenteric artery were quantitated from electron micrographs and compared at different ages. It was found that the renal artery rapidly accumulated extracellular material with increasing age; in the aortic tissue, however, the peak occurrence of extracellular material occurred at pubescence. Ultrastructural studies revealed a general tendency of aging medial smooth muscle cells to transform from a smooth, rounded morphology to become irregularly shaped.
For the purpose of preventing spread of infection to high risk children whose immunities were severely impaired by intensive chemotherapy or for some other reason, when cases of varicella occurred in a children's ward or in a family, healthy adults (mothers and a doctor) were immediately given live varicella vaccine, blood was collected from these adults 5 to 7 days after vaccination and the whole blood or plasma including the buffy coat was transferred in the high risk children. Subsequently the children showed little or no clinical reaction, and follow-up studies by the neutralizing test and skin test with varicella antigen indicated that their inapparent or subclinical varicella infection occurred in them and that their immunity to varicella was lasting. Skin tests with varicella antigen showed that booster reaction occurred in adults with a previous history of varicella as early as 5 to 7 days after vaccination. The cellular immunity thus induced in the donors may have played a role in preventing a clinical reaction in the high risk children. Thus passive transfer of vaccine-induced immunity seems a convenient and effective method for preventing infection in subjects whose immune capacities are severely impaired.
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Histological and ultrastructural studies were made of 25 specimens of human ductus arteriosus obtained from abortion of autopsy, and ranging in age from 15 weeks of gestation to 7 years. Samples of ductus with normal muscular type structure exhibited active intimal thickening as early as 15 weeks' gestational age when the internal elastic lamina was found to be focally discontinuous. At the same time, intimal smooth muscle cells were closely arranged, and often intimately connected to cells of the tunica media. Ultrastructurally, both smooth muscle cells and endothelial cells at 15 weeks' gestational age contained abundant glycogen deposits. From 18-32 weeks' gestational age, glycogen deposits gradually disappeared, collagen fibres began to appear in the extracellular space and the first signs of smooth collagen fibres began to appear in the extracellular space and the first signs of smooth muscle cell degeneration became apparent. After birth, intimal thickening and degeneration of smooth muscle cells was much more pronounced. The ultrastructure of intimal smooth muscle cells indicated that intimal thickening was caused by smooth muscle cell migration as opposed to rapid proliferation; and both intracellular and extracellular membrane-bound lipid-filled vacuoles were commonly seen in the more advanced stages of degeneration. Of the ductus specimens examined, three were rich in elastic fibres. Two of these three specimens were from a group of 10 abortion cases, and the third was from a 2 weeks old full term infant who had been exposed to maternal rubella. The 2 weeks old infant had a widely patent ductus arteriosus; whether the two fetal specimens with ductus elastosis would have eventually developed into clinical patent ductus arteriosus was not clear.
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Two cases of Ewing's sarcoma and two neuroblastoma, rosette forming and round cell type, were studied electron microscopically and their fine structures were compared. The neoplastic cells of Ewing's sarcoma were characterized by aggregated glycogen particles in the cytoplasm. They had pseudopod-like cytoplasmic processes having tight junctions, which never contained microtubules or mitochondria. Ewing's sarcoma cells exhibited several stages of cell maturation and some mature cells possessed a large amount of smooth and rough endoplasmic reticulum, large Golgi complexes and numerous phagosomes containing glycogen particles as well as cytoplasmic organelles. The neoplastic cells of neuroblastoma, rosette forming type, were characterized by synaptic junctions and numerous cytoplasmic processes with production of neurites containing microtubules, neurofibrils, mitochondria and a few catecholamine granules. A few cytoplasmic processes containing mitochondria were observed even in the round cell type.
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