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Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 973 records · Page 54Linked to original sources
PubMed1982

Cell surface glycoprotein and asparagine-linked sugar chain patterns of rat erythroleukemic cell lines.

In order to elucidate whether chromosomal change or induction of differentiation is correlated with the change of the patterns of cell surface glycoproteins and asparagine-linked sugar chains, glycoproteins and carbohydrates of five rat erythroleukemic cell lines (K1DB, D5A1, K2D, K2DA, and K4D) were studied by sodium dodecyl sulfate:polyacrylamide gel electrophoresis and hydrazinolysis followed by gel chromatography, respectively. The surface glycoprotein patterns of five cell lines were very similar, each containing four glycoproteins with molecular weights of 250,000, 115,000, 80,000, and 28,000, respectively. Only D5A1, which can be induced to erythroid differentiation, had two additional glycoproteins, with molecular weights of 135,000 and 65,000, respectively. All neutral oligosaccharides obtained from plasma membranes of five cell lines by hydrazinolysis were of the high-mannose type, and the acidic oligosaccharides were of the complex type with three different types of outer chains in various combinations: +/- NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc; Gal beta 1 leads to 3Gal beta 1 leads to 4GlcNAc; and Gal beta 1 leads to 4GlcNac beta 1 leads to 3Gal beta 1 leads to 4GlcNAc. An interesting finding was that two sugar chains, NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3(Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6)Man beta 1 leads to 4GlcNAc beta 1 leads to 4(+/-Fuc alpha 1 leads to 6)GlcNAcOT (in which the subscript OT indicates a NaB3H4-reduced oligosaccharide), were found only in surface carbohydrates of D5A1.

Animals↗
PubMed1982

Pathology of experimental radiation pancarditis. II. Correlation between ultrastructural changes of the myocardial mitochondria and succinic dehydrogenase activity in rabbit heart receiving a single dose of X-ray irradiation.

Twenty-three rabbits were given a single dose of 3,000R X-irradiation over the heart to study the correlation between the ultrastructural changes of myocardial mitochondria and succinic dehydrogenase activity. The study was made from 1 hour until 1 month after irradiation. The myocardial mitochondria showed, at 1 hour, regressive changes such as irregular arrangement, swelling, vacuolation, decrease and disappearance of cristae, formation of giant mitochondria, and whorled myelin figures. These changes became maximum at 12 hours-2 days. Regeneration of mitochondria had begun at 2 days. At 4-7 days, structurally normal mitochondria had markedly proliferated accompanied by large mitochondria with concentrically arranged cristae and small mitochondria around the nuclei and beneath the sarcolemma of myocardial cells. The myocardial succinic dehydrogenase activity, on the other hand, showed the lowest value at 12 hours--2 days, and recovered almost to the normal value at 7 days. At 2 weeks--1 month when myocardial fibrosis developed, however, the value again mildly decreased. Cardiac death due to radiation therapy may be initiated by the mitochondrial hypofunction in radiation myocardial fibrosis, because the irradiation injures the mitochondrial membrane resulting in morphological and functional changes.

Animals↗
PubMed1982

Resistance of mice to secondary infection with Schistosoma japonicum, with special reference to neutrophil enriched response to schistosomula in the skin of immune mice.

The lung recovery assay for schistosomula has been used as a rapid method for measuring acquired resistance to Schistosoma mansoni infection in challenged animals. This assay method was successfully utilized in the present study with S. japonicum in mice. Assay of resistance to reinfection with the lung recovery technique and with the conventional perfusion method demonstrated that a considerable level of resistance developed in mice which had received the primary infection of 30 S. japonicum cercariae 8 weeks prior challenge infection. In a histological study of this period, as early as 4 hours after challenge exposure there was already a dense accumulation of cells around a small proportion of schistosomula in the immune mouse skin. Light and electron microscopy revealed that the adherent cells were mainly neutrophils. There was a more increase in the cellular reaction around the schistosomula in the skin 24 hours after challenge and the cells of this reaction were still predominantly neutrophils with a few eosinophils. A small proportion of these entrapped schistosomula showed structural damage. In contrast, schistosomula in the lungs of immune mice were essentially without cellular association. It appears from our work that the adherence of neutrophils to schistosomula in immune mouse skin contributes to a reduction in the number of worms which subsequently develop.

Animals↗
PubMed1982

[Correlation of vasospasm with operative results in ruptured aneurysms].

The present study is a retrospective clinicoradiological correlative investigation of subarachnoid hemorrhage associated with ruptured aneurysms. There were 360 patients in whom the source of subarachnoid hemorrhage was shown by angiography to be a ruptured aneurysm, and 302 of them underwent surgery. Arterial vasospasm was demonstrated in 113 of 360 patients (31%). When the time relationship between the subarachnoid hemorrhage and vasospasm was considered, vasospasms were revealed in 35 patients (31%) to ten days after a hemorrhage. In these cases with preoperative vasospasm, 17 patients were operated within 14 days and 43 patients later than two weeks. On the examination, their clinical state was graded according to Hunt and Hess. The surgical results were also grade in five groups (excellent, good, fair, poor and died) according to the functional results at discharge from the hospital. Of 35 patients of grade I and II at operation, 23 patients (66%) were of excellent or good results. However, of 14 patients of grade IV and V at operation, only on patient took good result. Of 12 patient in whom severe vasospasm was demonstrated and surgery was delayed more than two weeks, 8 patients (66%) had good result. Postoperative vasospasm was recognized in 2 patients, who took poor result. Surgery was carried out in 32 patients on the first or second day after subarachnoid hemorrhage, and 7 patients (22%) of them took good result. The overall mortality was 59% (19 patients). In ten patients, surgery was carried out on the third or fourth day after subarachnoid hemorrhage. Five patients had good result (50%) and four (40%) died. Considering the relationship between the timing and result of surgery, the mortality was 35% in patients operated on in the first week, whereas there were only 38 deaths among the 252 patients operated on after that interval. Among the death patients who were in grade IV or V at admission, intracranial hematoma was seen in 73%. It was concluded that in patients classified as grade I or II, the operation should be performed as soon as possible to prevent another rupture. In grade IV and V patients with severe damage by large hematoma, the mortality and morbidity were high even after evacuation of the hematoma. Patients with marked and diffuse vasospasm should be given conservative treatment at first and then operated on when the patients condition becomes good.

Adult↗
PubMed1981

Recombinant human leukocyte interferon produced in bacteria has antiproliferative activity.

Recombinant human leukocyte interferon synthesized by Escherichia coli possesses antiproliferative activity in addition to antiviral activity. When the ability to inhibit multiplication of lymphoblastoid Daudi cells was examined, the growth-inhibitory capacity of recombinant leukocyte interferon was equivalent to that exhibited by crude human leukocyte interferon or by the homogeneous gamma 2 species of leukocyte interferon synthesized by human cells.

Cell Division↗
PubMed1981

Growth patterns of temperature-sensitive mutants of Western equine encephalitis virus in cultured Aedes albopictus (mosquito) cells.

Several temperature-sensitive (ts) mutants of Western equine encephalitis virus (WEEV) have been isolated previously from persistently infected cultures of mosquito cells and divided into three groups: early passage RNA- mutants, early passage RNA+ mutants and late passage RNA- mutants (Maeda et al., 1979(. The growth patterns of these groups, as well as of several ts mutants isolated after chemical mutagenesis and of wild-type (wt) WEEV, have been compared in BHK cells and in two strains of mosquito cells. The late passage ts mutants grew much better in mosquito cells than either the wt WEEV or the chemically induced mutants. When mosquito cells were co-infected with a late passage mutant (A125) and Wt WEEV, infectious virions of both parental types as well as phenotypically mixed particles were produced. Infection of mosquito cells with WEEV resulted in a slight suppression of host DNA and protein synthesis during the acute stage of the infection (the first 1 or 2 days). Virus growth in a line of cloned mosquito in which WEEV produced a cytopathic infection (c.p.e.) was analysed with the result that the viruses could be divided into two groups: one in which wt WEEV, chemically induced ts mutants and early passage RNA+ mutants all induced maximal c.p.e., and another in which late passage RNA- mutants and one early passage RNA- mutant induced very little c.p.e., but released much more infections virus into the culture fluid. Electron microscopy showed that in these cloned mosquito cells infected with a virus of the first group, large amounts of virus accumulated on or in the plasma membrane.

Aedes↗