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Showing papers by "Kumamoto University published in 1976"


Journal ArticleDOI
TL;DR: Chick primordial germ cells (PGCs) which separated from the “germinal crescent” entoderm in the period from stages 4 to 8 circulated mostly through the developing blood vessels from stage 10 onward and finally migrated into the gonad.
Abstract: Chick primordial germ cells (PGCs) which separated from the "germinal crescent" entoderm in the period from stages 4 to 8 circulated mostly through the developing blood vessels from stage 10 onward and finally migrated into the gonad. The PGCs making their appearance up to this stage were generally spherical in profile, about 14 mum in diameter. Some of the PGCs in contrast, did not enter the blood vessels but remained in the tissue (mesenchyme) of the embryo proper (tissue PGCs) and possessed pseudopodial processes, suggesting their migration by means of amoeboid movements. The circulating PGCs emerged from blood vessels in the vicinity of developing gonads by three days (gonadal PGCs). The principal mechanism responsible for the subsequent migration of gonadal PGCs is assumed to be amoeboid movements as in the case of tissue PGCs. Notable amounts of PAS-positive glycogen were demonstrated in the cytoplasm of PGCs in all stages obsreved. They also contained yolk and lipids intracytoplasmically, the former dissipating in relatively early stages of development. Electron microscopic observation revealed the electron-opaque, "fragmented nucleolus" in the large nucleus (8 mum in diameter), which represented another prominent feature of chick PGCs. PGCs contained a well-developed Golgi complex and endoplasmic reticulum.

195 citations


Journal ArticleDOI
TL;DR: In this article, the authors define the congruence subgroup modulo α of a Chevalley-Demazure group scheme associated with a connected complex semi-simple Lie group Gc.
Abstract: 0. Introduction. Let G be a Chevalley-Demazure group scheme associated with a connected complex semi-simple Lie group Gc (as for the definition, see E. Abe [1], 1) and let R be a commutative ring with a unit, α an ideal of R. Then the natural ring homomorphism f:R—+R/a induces the group homomorphism (?(/): G{R) —• G(R/a). The kernel (resp. the inverse image of the center of G(R/a)) of G(f) will be denoted by G(R, α) (resp. G*(R, α)) and called the special (resp. general) congruence subgroup modulo α of G(R). Any subgroup N of G{R) such that

135 citations


Journal ArticleDOI
TL;DR: It may be concluded that the primary action of CH 3 HgCl is on the presynaptic site, whereas that of H gCl 2 is both on the pre-and postsynaptic sites, and that either spontaneous or evoked transmitter release was similarly suppressed after long-term exposure.

69 citations


Journal ArticleDOI
TL;DR: In phase contrast microscopy, living PGCs in the blood and from the primitive gonad of 3-day embryos in parts of the examinations were observed to change their shape in somewhat amoeboid fashion, suggesting their capability for locomotion as a possible mechanism of the migration of P GCs in vivo.

67 citations


Journal ArticleDOI
01 May 1976-Polymer
TL;DR: In this paper, Nitroxide radicals were dispersed as paramagnetic probes in natural and acrylonitrile-butadiene rubbers, differing in the content of combined sulphur, and their molecular motions were investigated through the motion of the probe inspecting e.s.r. spectra.

63 citations


Journal ArticleDOI
TL;DR: In this article, a tinite element method of mixed type was proposed to solve the Dirichlet problem of the von Karman equations, and the existence and convergence of the approximate solution were proved.
Abstract: A tinite element method of mixed type is proposed to solve the Dirichlet problem of the von Karman equations. Existence and convergence of the approximate solution are proved.

50 citations


Journal ArticleDOI
TL;DR: It was evident that the colony formation was caused by clonal transformation by EBV, and the colonies were similarly induced, but with a lower efficiency, in adult peripheral blood leukocyte cultures infected with the virus.
Abstract: The B95-8 strain of Epstein-Barr virus (EBV) induced colony formation of human umbilical cord-blood leukocytes in soft agar medium. One-hit response relationship between the number of colonies and the virus dose was observed with high dilutions of the virus preparation. However, there was a presumed cell-killing effect with low dilutions of virus. The colonies were similarly induced, but with a lower efficiency, in adult peripheral blood leukocyte cultures infected with the virus. The colony-forming activity of EBV was neutralized by anti-EBV-positive but not by negative human sera. The cells in colonies were capable of growing continuously and carried EBV-associated nuclear antigen. Thus, it was evident that the colony formation was caused by clonal transformation by EBV.

44 citations


Journal ArticleDOI
TL;DR: The result is consistent with the idea that the heat-induced increase in brain serotonin turnover is mediated by an increased firing rate of midbrain raphe neurons.
Abstract: The effect of heating and cooling in the midbrain on the unit activities of midbrain raphe neurons in the rat was observed. Out of 24 raphe units studied, 14 units responded to a rise in midbrain temperature with an increased rate of firing. The remaining 10 units did not respond to temperature changes between 34 and 41 degrees C. The result is consistent with the idea that the heat-induced increase in brain serotonin turnover is mediated by an increased firing rate of midbrain raphe neurons.

40 citations


Journal ArticleDOI
TL;DR: Drastic changes in the absorption and circular dichroic spectra of the enzymes which took place during the inactivation indicated that the modification by L-propargylglycine is restricted to the active site of these isoenzymes.

39 citations


Journal ArticleDOI
TL;DR: The active centre model of bleomycin, proposed in the recent paper, has developed in such a way as to reveal the precise physical structure of the bleomyin molecule as a whole and to clarify the mode of binding interaction of this antibiotic molecule with the helically arranged DNA.

39 citations


Journal ArticleDOI
TL;DR: The cross sensitizations among maneb, mancozeb and zineb were estimated to be extreme in potentiality of causing contact sensitization, but there were not so dominant reactions in cases of other combinations tested.
Abstract: Allergenicity of the dithiocarbamate fungicides maneb, mancozeb, zineb and their related compounds were evaluated from the guinea pig maximization test. Extreme to strong potency of allergenicity were revealed for maneb, mancozeb and zineb as well as one of their related compound lime sulphur mixture. But, such degree of allergenicity was not observed in cases of ethylene thiourea and dimethyl dithiocarbamic acid sodium salt. The cross sensitizations among maneb, mancozeb and zineb were estimated to be extreme in potentiality of causing contact sensitization, but there were not so dominant reactions in cases of other combinations tested.


Journal ArticleDOI
TL;DR: The sural nerves of 2 human cases with Minamata disease and poisoned rats were examined histopathologically and small myelinated nerve fibres were increased, which may be characteristics of the late changes of the sural nerve induced by organic mercury compound.
Abstract: The sural nerves of 2 human cases with Minamata disease and poisoned rats were examined histopathologically. Both showed similar findings: the myelinated nerve fibres were decreased in number, but small myelinated nerve fibres were increased: The latter were irregular in shape and their Schwann cells showed regressive changes, with high electron density of the cytoplasms and many glycogen granules. Onion bulb formation was not found. According to fibre diameter histograms, the ratio of small myelinated nerve fibres of 2-5 mum showed a high percentage. A large number of the small myelinated nerve fibres were presumed to be regenerated nerve fibres. These findings are different from other peripheral neuropathies and may be characteristics of the late changes of the sural nerve induced by organic mercury compound.

Journal ArticleDOI
TL;DR: An actinomycete, strain No.
Abstract: An actinomycete, strain No T-1124, was found to produce new macrolide antibiotics, juvenimicins Based on the results of taxonomic studies, the strain was considered to be a new variety of micromonospora chalcea and the name Micromonospora chalcea var izumensis is proposed This strain also produced everninomicin The production of juvenimicins was stimulated by addition of ferrous sulfate and magnesium sulfate in the fermentation medium Among juvenimicins, juvenimicin A3 exhibited the most potent antimicrobial activities against gram-positive bacteria and furthermore was active against gram-negative bacteria

Journal ArticleDOI
TL;DR: An excessive accumulation of sugar just before the reddening indicated that the accumulation related to the anthocyanin formation, and the incorporation of radioactivity into anthocianin in autumn leaves from glucose-[U-14C] and phenylalanine]-U- 14C was observed.
Abstract: Seasonal variation in sugar, total phenol and flavanol contents was examined inRhus, Euonymus andAcer leaves. In all plant leaves, the total phenol and flavanol content per leaf increased rapidly at the early growth stages but thereafter the content was kept rather constant. Later on, sugar content increased to a high level, and the autumnal reddening began. An excessive accumulation of sugar just before the reddening indicated that the accumulation related to the anthocyanin formation. The incorporation of radioactivity into anthocyanin in autumn leaves from glucose-[U-14C] and phenylalanine-[U-14C] was also observed.

Journal ArticleDOI
TL;DR: It was shown that theEBV susceptibility of adult cells was not only lower but also much more variable between individuals than that of cord cells, and in cultures of mixed cord cells and adult cells known to have low EBV susceptibility, the minimum MOI increased in proportion to the amount of adult Cells.
Abstract: Susceptibility of lymphocyte-enriched cell fractions isolated from human umbilical cord blood and adult peripheral blood to transformation by the B95–8 strain of Epstein-Barr virus (EBV) was investigated quantitatively. Minimum multiplicity of input of virus (50% transforming dose) per cell (MOI) necessary to induce maximum level transformation of cord cells ranged from 0.02 to 0.2. The frequency of initially transformed cells (fraction of transformable cells) in the cord cell samples from two different individuals was estimated to be 2.6 to 6.2%. In this system, the appearance of cells positive for EBV-associated nuclear antigen (EBNA) paralleled the growth curve of transformed cells. About 70% of the latter were EBNA-positive. In adult cell preparations from two individuals, 1.8 and 0.03%, respectively, of the cells were transformable indicating larger individual variations in sensitivity to EBV than in cord cells. The EBV susceptibility was also determined by the transforming efficiency (TE) expressed as the negative log of the virus dilution which induces transformation in 50% of cell cultures infected at an MOI of 0.2. From the TE value, a minimum MOI which induces transformation could be calculated. Also by this test it was shown that the EBV susceptibility of adult cells was not only lower but also much more variable between individuals than that of cord cells. There was no correlation between the susceptibility of cells and the titer of anti-EBV antibody in donors' sera. In cultures of mixed cord cells and adult cells known to have low EBV susceptibility, the minimum MOI increased in proportion to the amount of adult cells. Analyse quantitative de la sensibilitb des leucocytes humains a la transformation par le virus d'epstein-barr Les auteurs ont eflectue une analyse quantitative de la sensibilite' des fractions cellulaires riches en lym-phocytes isolees a peripherique d' la transformation par la souche B95-8 du virus d'Epstein-Barr (EBV). La mrrltiplicitt minimale d'infection virale (TD50) par cellule (MOI) necessaire pour induire une transformation maximale des cellules du cordon variait entre 0.02 et 0.2. Le pourcentage estimatif de la fre des cellules initialement transformees (fraction de cellules transfortnables) dans les preclevements de cellules du cordon de deux sujets difftrents allait de 2.6 ´ 6.2%. Dans ce systeme, I'apparition des rellrrles positives pour I'antigene nucleaire associe ´ I'EBV (EBNA) etait parallele ´ la courbe de croissance des cellules transformees. Environ 70 % de ces dernikres etaient EBNA-positives. Dans les prkparations cellulaires provenant de deux adultes, respectivement 1.8 et 0.03% des cellules etaient transformables, ce qui indique que les variations individuelles de la sensibilite a l'EBV sont plus fortes que dans les cellules du cordon. La sensibilite a l'EBV a aussi ete determinee d'apres l'efficacite de transformation (TE) exprimee comme le logarithme negatif de la dilution du virus qui induit une transformation dans 50% des cultures infectees a une MOI de 0.2. Cette valeur a permis de calculer une MOI minimale qui induit la transformation. Ce test a egalement montre que la sensibilite a l'EBV des cellules d'adultes est non seulement plus faible mais aussi beaucoup plus variable entre les individus que celle des cellules du cordon. Il n'y a aucune correlation entre la sensibilite des cellules et le titre d'anticorps anti-EBV dans le serum des donneurs. Dans les cultures de cellules du cordon melangees a des cellules d'adultes, que l'on sait peu sensibles a l'EBV, la MOI minimale s'est accrue proportionnellement a la quantite de cellules du cordon. Les deux methodes utilisees pour determiner la sensibilite des cellules a l'EBV ont donne des resultats comparables.

Journal ArticleDOI
TL;DR: Cadmium in the bile of the rats administered cadmium chloride with the chelating agents such as citric acid, D-cysteine, and DL-penicillamine was largely bound to the substances with a low molecular weight.
Abstract: The excretion of cadmium through the bile and gastrointestinal mucosa after the intraperitoneal administration of cadmium chloride and the effect of the chelating agents such as ethylenediaminetetraacetic acid, citric acid, 2, 3-dimercapto-1-propanol, L-cysteine, D-cysteine, and DL-penicillamine on its excretion were studied in rats. The cumulative biliary excretion of cadmium in a 9 hr period was about 0.85% of the injected dose. Citric acid, D-cysteine, and DL-penicillamine increased the biliary excretion of cadmium. All of the chelating agents used scarcely affected the excretion of cadmium through the gastrointestinal mucosa. Moreover, chemical characteristics of cadmium complex in the bile were investigated by the chromatography on Sephadex G-75 of the bile from the rats receiving cadmium chloride. The results showed that cadmium was bound to several bile components with different molecular weights, and that cadmium in the bile of the rats administered cadmium chloride with the chelating agents such as citric acid, D-cysteine, and DL-penicillamine was largely bound to the substances with a low molecular weight.

Journal ArticleDOI
TL;DR: The results indicate that the membrane potential in taste cells originates from the diffusion potential due to receptor membrane permeable to monovalent cations and anions, and that anions modify the membrane permeability to both ion species.


Journal ArticleDOI
TL;DR: This article found that water elicited a slowly rising and persistent response, but no difference in sensitivity to water was found among the three portions of the tongue, but the hyperpolarization decreased by about 10-40 mV during water stimulation.

Journal ArticleDOI
TL;DR: The present case of Neuro-Behçet's disease is the first one showing general atrophy of the cerebrum, and it is suggested that these changes were caused by an allergic vasculitis.
Abstract: A 38-year-old female died 6 years after the onset of what was, clinically and histopathologically, consistent with Neuro-Behcet's disease. Pathologically the cerebrum showed severe atrophy. The main changes were observed in the grey and white matter, the diencephalon and the basal ganglia by light microscopy. All these changes originated in softenings around blood vessels, especially small vessels or capillaries. These foci fused together to form large regions of softening. Glial or mesenchymal reactions were minimal. In the white matter there was slight perivascular-infiltration, mainly consisting of lymphocytes. In view of these findings, it is suggested that these changes were caused by an allergic vasculitis. The present case of Neuro-Behcet's disease is the first one showing general atrophy of the cerebrum. It is very important in relation to demyelinating encephalitis.

Journal ArticleDOI
TL;DR: Streptomyces sp.
Abstract: Streptomyces sp. strain No. K-245 was found to transform maridomycin III into four derivatives (A1, A2, A3 and A4) in addition to the transformation products reported previously. Isolation of the main product A1 was carried out by column chromatography on silica gel developed with CHCl3-MeOH (19:1). From the partial investigation of the structure of A1 it proved to have a C 18-aldehyde group and C 4"-propionyl group but no antimicrobial activity. The relationships between A group's derivatives and known derivatives of maridomycin III are also discussed.

Journal ArticleDOI
TL;DR: When the effects of quinine, brucine and caffeine on electrical responses in taste cells were examined, they all produced a depolarization associated with an increased input resistance, and the action of the three compounds on taste receptors operates with a similar mechanism.
Abstract: Effects of some bitter-tasting compounds on frog taste receptors were examined by recording glossopharyngeal nerve responses. The order of effectiveness of the compounds was quinine greater than brucine greater than formanilide greater than caffeine greater than urea. When the effects of quinine, brucine and caffeine on electrical responses in taste cells were examined, they all produced a depolarization associated with an increased input resistance. The action of the three compounds on taste receptors therefore, operates with a similar mechanism. The electrical responses in cells, produced by quinine, progressed slowly with time. Such effects with quinine are similar to those with procaine. After adaptation to quinine, the nerve responses to various chemical stimuli were gradually reduced in magnitude, while the electrical responses in taste cells during stimulation by chemicals became smaller. The mechanism of the effects of bitter stimuli are discussed in light of recent findings on the interaction of bitter stimuli with lipid monolayers and the extraction of lipid from bovine taste papillae by bitter stimuli.

Journal ArticleDOI
TL;DR: The study showed that the presumptive neuro‐ectoderm consisted mainly of cells of the fifteenth generation (G‐15) at the onset of gastrulation (pigment stage) and the synchronous cleavage of the blastomeres at the animal pole continued for 18 hr until the twelfth cleavage (mid‐blastula).
Abstract: Cell proliferation was examined during early embryogenesis of the newt (Triturus pyrrhogaster) by various methods. After the two-cell stage, at 23°C, the blastomere (cell) number per whole embryo increased logarithmically until the mid-blastula stage (for about 19 hr) and the rate of increase slowed down in and after the late blastula stage. On the other hand, the synchronous cleavage of the blastomeres at the animal pole continued for 18 hr until the twelfth cleavage (mid-blastula) and the transition from synchronous to asynchronous division occurred abruptly at and after the thirteenth cell division (late blastula). The study also showed that the presumptive neuro-ectoderm consisted mainly of cells of the fifteenth generation (G-15) at the onset of gastrulation (pigment stage). The present study suggested that the number of ectodermal cells of the early gastrula (stage 12a) nearly doubled during gastrulation at the presumptive neuro-ectoderm. This means that most of the ectodermal cells are in G-16 at the end of gastrulation. On the other hand, both mitotic activity and the rate of cell increase gradually diminished during gastrulation in the ectoderms of both the presumptive neural and epidermal regions, and there are evidently significant differences in both activities between the neuro-ectoderm and the epidermal ectoderm after stage 13b: the epidermal ectoderm showed greater decrease in the rate of both mitotic activity and cell proliferation than the neuro-ectoderm. These facts suggested that, whether the ectodermal cells will differentiate into neural cells or epidermal cells is determined during G-15 or G-16 in normal primary induction.

Journal ArticleDOI
TL;DR: The enantioselective dehydrogenation of racemic (R-(+) and S-(−)) α-phenylethanol by RuCl2(PPh3)3 and (+)-neomenthyldiphenylphosphine at 180°C showed constant ratios of kR Ω(kS) in the absence of benzalacetone.
Abstract: The enantioselective dehydrogenation of racemic (R-(+) and S-(−)) α-phenylethanol by RuCl2(PPh3)3 and (+)-neomenthyldiphenylphosphine at 180°C showed constant ratios of kR⁄kS in the absence of benzalacetone. The kR⁄kS value increased almost linearly with the benzalaceton concentration and decreased with the larger amounts of the chiral phosphine under the present reaction conditions.

Journal ArticleDOI
TL;DR: The findings indicate that glucose may play an important role in the mechanical performance of the heart perfused with a solution containing isoproterenol.

Journal ArticleDOI
TL;DR: In this article, the elution volumes of the complexes were measured as functions of the concentration and pH of the eluents, sample concentration and gel porosity, and the concentration dependence of the sample could be classified into two types, M II Y 2- and M III Y -.

Journal ArticleDOI
TL;DR: In vivo distribution of the succinyl derivative of the antitumor antibiotic, neocar zinostatin (NCS), was studied in rats and NCS seems to be excreted into the urine both in the degraded forms and in almost intact forms.

Journal ArticleDOI
TL;DR: Two different factors chemotactic for cancer cells were extracted in pseudoglobulin fraction of rat ascites hepatoma transplanted tissue and it was assumed that the combined action of these two factors may be involved in malignant invasion.
Abstract: Two different factors chemotactic for cancer cells were extracted in pseudoglobulin fraction of rat ascites hepatoma transplanted tissue. After chromatography on Sephadex G-50 and CM-Sephadex, these factors were separated by gel filtration on Sephadex G-100. The factora was further fractionated by immunoadsorbent chromatography with goat antirat γ-globulin antibody and then with rabbit antirat hemoglobin antibody; it was a protein with a molecular weight of about 78,000, resembling a chemotactic factor previously reported, and its activity was thermolabile. The previously undescribed factor 6 was also a protein with a molecular weight of about 14,000 and its activity was thermostable. Intradermal injection of these factors at low concentrations induced an extravascular migration of circulating tumor cells and formation of metastatic secondary tumors; and little difference in the in vivo effect between these factors was observed. It was thus assumed that the combined action of these two factors may be involved in malignant invasion.

Journal ArticleDOI
TL;DR: Both CH3HgCl and HgCl2 at 0.04–0.4 m m were found to have a dose-related depressive effect on the twitch height of isolated frog sartorius muscles, and CH3hgCl was particularly effective in suppressing the twitches induced by indirect stimulation.