Showing papers by "Kumamoto University published in 1973"

Improved point-matching method with application to scattering from a periodic surface

Abstract: The method of modal expansions is a fundamental technique for solving the electromagnetic boundary value problems. As its practical alogrithm, the point-matching method has been used but frequently failed. A new computer-aided procedure based on the method of modal expansions is presented and applied to the scattering from a periodic structure composed of a perfectly conducting surface. As an example, the scattering from the grating with a sinusoidal height profile is calculated. It is demonstrated numerically that the new procedure leads to desirable results, while the point-matching method does not. Several physical characteristics on the reflection grating including the diffraction anomalies are explored.

Spongiocaris, a New Genus of Stenopodidean Shrimp From New Zealand and South African Waters, With a Description of Two New Species (Decapoda Natantia, Stenopodidea)

Abstract: [Des crevettes de la famille des Stenopodidae obtenues recemment dans les eaux profondes, pres des cotes de l'Afrique du Sud et de la Nouvelle Zelande, representent deux especes d'un genre non-decrit. Une definition du nouveau genre, Spongiocaris, est donnee, et ses rapports avec les genres proches, Spongicola de Haan et Spongicoloides Hansen, sont discutes. Les descriptions des deux nouvelles especes, S. semiteres et S. yaldwyni, sont fournies, avec des illustrations. Les deux especes ont ete toutes deux trouvees en association avec des eponges hexactinellides, entre 512 et 622 metres de profondeur., Des crevettes de la famille des Stenopodidae obtenues recemment dans les eaux profondes, pres des cotes de l'Afrique du Sud et de la Nouvelle Zelande, representent deux especes d'un genre non-decrit. Une definition du nouveau genre, Spongiocaris, est donnee, et ses rapports avec les genres proches, Spongicola de Haan et Spongicoloides Hansen, sont discutes. Les descriptions des deux nouvelles especes, S. semiteres et S. yaldwyni, sont fournies, avec des illustrations. Les deux especes ont ete toutes deux trouvees en association avec des eponges hexactinellides, entre 512 et 622 metres de profondeur.]

In vitro effects of synthetic somatotropin-release inhibiting factor on cyclic AMP level and GH release in rat anterior pituitary gland.

Abstract: Synthetic somatotropin-release inhibiting factor (10ng/ml) decreased significantly basal level of cyclic AMP concentration and showed marginal inhibition of GH release in rat anterior pituitary gland in vitro. Higher dose of synthetic somatotropinrelease inhibiting factor was needed to produce significant inhibition of GH release from the gland. Results obtained in the experiments suggest that somatotropin-release inhibiting factor as well as hypothalamic releasing hormones may act through adenyl cyclase-cyclic AMP system in the anterior pituitary gland.

The distribution of manganese and iron between ilmenite and granitic magma in the Ôsumi Peninsula, Japan

Abstract: Manganoan ilmenite with a variable manganese content occurs as an early accessory constituent of granitic rocks in the Osumi Peninsula, southern Kyushu. Electron probe micro-analysis of a grain containing highest manganese gives the structural formula (Fe 1.23 2+ Mn 0.81 2+ ) (Ti1.97) O6, if all of the manganese and iron are in the divalent state. The manganese content of manganoan ilmenite increases with an increase of the differentiation index of host rocks, however, the amount of ilmenite tends to decrease with the increase of the same index. The mode of occurrence of the ilmenite suggests that it is the first mafic mineral to precipitate from the magma. The average value of the distribution coefficient of manganese and ferrous iron between ilmenite and granitic magma is 5.5, if the Mn/Fe ratio of the granitic rocks represents that of granitic magma. The variation in the FeO and MnO contents against the differentiation index for granitic rocks of the Osumi Peninsula, and the value of the distribution coefficient, show that high manganoan ilmenite is stable in the most differentiated granitic rock of the Osumi Peninsula.

The enhancing action of 5'-ribonucleotide on rat gustatory nerve fiber response to monosodium glutamate.

Abstract: Responses of single chorda tympani fibers of rats to gustatory stimulations by monosodium glutamate (MSG) of varying concentrations with or without the presence of a fixed amount of sodium 5'-guanylate (5'-GMP) were recorded. The effect of addition of 5'-GMP to MSG differs according to the response characteristics of the unit. In units predominantly responsive to NaCl, little enhancement was observed in the response magnitude with the addition of 5'-GMP, but in units responding well to sucrose a marked enhancement occurred. In a majority of these units, not only a synergistic enhancement in the response magnitude but also a marked lowering of threshold was obtained after the addition of 5'-GMP. The relative magnitude of enhancement was greater at a lower concentration of MSG, and decreased with increasing concentration. Analysis of the concentration-response magnitude relationships suggests that the synergistic action of MSG and 5'-GMP on gustatory receptors is a mechanism known as ‘competitive and noncompetitive’ sensitization.

An ATP pool associated with adenyl cyclase of brain tissue.

Abstract: Radioactive adenine has been frequently used to label cyclic adenosine 3′, 5′-monophosphate (cAMP) in diverse cells and tissues (Kuo and DeRenzo, 1969; Shimizu, Daly and Creveling, 1969, Brooker, 1971). We have previously reported that cAMP from the guinea-pig cerebral cortex is derived from a precursor pool of adenine nucleotides which is more highly labelled than the bulk cellular ATP (Shimizu, Creveling and Daly, 1970a). The present study was carried out to throw additional light on the property of the precursor pool. Levels of cAMP and ATP and specific activities of [14C]cAMP and [14C]ATP were determined simultaneously in cerebral slices which were prelabelled with [14C]adenine and subsequently incubated with veratridine, histamine or adenosine.

Isolation of the sugar-binding protein from rat taste buds.

Abstract: DASTOLI and Price1 have found a protein fraction in bovine tongue extracts that complexes with sugars and saccharin and has some of the properties expected of the sweet taste receptor molecule. A similar protein fraction has also been demonstrated in 0.4–0.6% saturation (NH4)2SO4 fraction of extract from rat tongue, but not in extract from cat tongue, which has little sensitivity to sugars2. Also, the order and the relative magnitude of effectiveness of nine sugars on the fraction of extract from rat tongue epithelium, shown by measuring changes in ultraviolet absorbancy of the protein complex with sugars, agree with those obtained electrophysiologically in the rat3. On the other hand, Koyama and Kurihara4, after comparing the protein pattern obtained from papillae with taste buds with those from the surrounding epithelium, concluded that a unique protein was not present in taste buds in the bovine tongue. Their inability to find any difference in the protein pattern between extracts from the two kinds of papillae may be due to the minute amount of the specific protein in the taste buds, because their results are not compatible with the finding that suspensions of circumvallate and fungiform papillae bound more 14C-labelled sucrose than did those from filiform papillae, which are devoid of taste buds5. The presence of a minute amount of the sugar-binding protein has been demonstrated at the anodal side of the disc electrophoresis of 0.4–0.6% saturation (NH4)2SO4 fraction of extract from rat tongue epithelium6. This sugar-binding protein band was stained by amido black or Coomsian bright and showed a high radioactivity after 14C-fructose had been added to the fraction.

On the relationship between membrane potential and tension inMytilus smooth muscle

Abstract: 1 The relationship between the membrane potentials and tension was investigated inMytilus smooth muscle 2 The spike potential was inhibited by 1 mM Mn, while the Ach potential and tension were not affected by Mn 3 Removal of external Na blocked both the Ach potential and initiation of tension but had no appreciable effect on the tension maintenance 4 On the application of Ach (10−4 M), maximum depolarization, up to 25 mV, was attained and after washing out Ach, the membrane was repolarized, while tension was maintained 5 In conclusion, the spike potential is not essential for tension development but the slow depolarization is enough to initiate tension The role of intracellular Ca responsible for the tension development was discussed

A biopsy case of Wilson's disease. Pathological changes in peripheral nerves.

Abstract: The sural nerve from a patient with'Wilson's hepato-lenticular degeneration was examined by electron microscopy. The myelin sheaths showed remarkable changes and the axons secondary changes, while the unmyelinated nerve fibres were intact. These findings demonstrate that pathological changes of peripheral nerves occur in Wilson's disease. The changes are considered to be primary degeneration of the myelin sheaths.

Macromolecular particles of polyglucose synthesized under histochemical conditions in the endothelial cells of rabbit blood vessels.

Abstract: New polyglucose was synthesized artificially under histochemical conditions from glucose 1-phosphate by phosphorylase and branching glycosyltransferase in the endothelial cells of rabbit blood vessels. In electron micrographs it appeared as a large macromolecular structure of spheroidal branching bodies. The polyglucose particles were much larger in size than those observed previously. They were synthesized in intracellular cytoplasmic matrices and also within nuclei.

Gustatory coding in the cat chorda tympani fibers sensitive and insensitive to water.

Abstract: 1. Impulse discharges in single chorda tympani fibers of the cat in response to gustatory and thermal stimulations of the tongue were recorded. Fibers were classified into water-sensitive and -insensitive ones; the magnitudes of responses to 0.5 M LiCl, NaCl, CaCl2 and SrCl2 were significantly greater in the latter than in the former.2. The water response in water-sensitive fibers was depressed when a small amount of salts was added to water. The maximum depressing effects were compared among cations of Cl salts and the following order was obtained: Li+>Na+>Sr++>K+>Mg++>Ca++>NH4+. An approximately inverse order was obtained regarding the stimulating action of these cations on water-sensitive fibers.3. Statistical calculations of the frequency of responses of chorda tympani fibers to single gustatory stimuli or combinations of stimuli were made, assuming that responsiveness to any one stimulus is independent of that to other stimuli. No evidence of relatively specific sensitivity to a particular stimulus or a particular combination of stimuli was obtained in the cat.4. Across-fiber correlation coefficients between the degrees of response to a pair of stimuli were calculated. Highly significant correlations were found between HCl and cooling, LiCl and NaCl, CaCl2 and SrCl2, and KCl and either MgCl2 or NH4Cl.

Maridomycin, a new macrolide antibiotic. I. Taxonomy and fermentation.

Abstract: 9-Propionylmaridomycin (PMDM) and maridomycin (MDM) were transformed into 4"-deacyl-9-propionylmaridomycin (PMDM-M) and 4"-deacylmaridomycin (MDM-M), respectively, by incubation with rat liver homogenates in pH 7.2 buffer solution. The structures of these products were elucidated from their physicochemical properties and the result of chemical conversions into the known derivatives of MDM. Furthermore, PMDM-M was isolated as a main metabolite from the urine of rats treated with PMDM by oral route. On the other hand, from human urine after oral administration of PMDM, three metabolites were recovered and identified as PMDM-M, MDM and MDM-M by direct comparison.

Syntheses and Properties of Some Pyrrolo[2,3-d]pyrimidine Derivatives

Abstract: The reaction of 6-amino-1, 3-dimethyluracil (I) with phenacyl bromide in DMF gave 1, 3-dimethyl-6-phenylpyrrolo [2, 3-d] pyrimidine-2, 4 (1H, 3H)-dione (II) in high yield. The reaction of I and phenacyl bromide in acetic acid afforded the isomeric 1, 3-dimethy1-5-phenylpyrrolo [2, 3-d] pyrimidine-2, 4 (1H, 3H)-dione as a byproduct besides II. Nitrosation of II gave 1, 3-dimethy1-5-nitroso-6-phenylpyrrolo [2, 3-d] pyrimidine-2, 4 (1H, 3H)-dione (III) along with the corresponding 5-nitro derivative. Ring expansion of III by the Beckmann rearrangement was carried out to give 1, 3-dimethy 1-5-hydroxy-6-phenylpyrimido [4, 5-d]-pyrimidine-2, 4 (1H, 3H)-dione. Denitrosation of III by the action of sulfuric acid was observed.

Gamma-Ray Energies and Half-Lives of Praseodymium-148 and -149

Abstract: Rapid separation using NTA in paper electromigration was applied to the study of the γ-decay of 148Pr and 149Pr produced in the fission of 235U. The γ-ray spectrum was measured with a high-resolution Ge(Li) detector. The γ-transitions found to decay with half-lives shorter than 3 min were: 135, 162, 256, 300, 511, 614, 696, 868, 1,022 and 1,248 keV. Of these, the values of 300 keV, and of 135 and 162 keV were in fair agreement with those reported for 148Pr and 149Pr. The decay plot of the strong photopeak of 300 keV presented good linearity and the accurate half-life of 148Pr could be determined as 2.30±0.03 min, which is longer than the 1.98 min reported for 148Pr. Similar decay plots of both photopeaks at 135 and 162 keV gave a half-life of 2.9±0.1 min for 149Pr, which again is longer than the reported value of 2.3 min. Other low intensity photopeaks at 256, 696, 868 and 1,022 keV decaying with half-lives of 2.1∼2.4 min can possibly be attributed to 148Pr. The γ-transitions of 110, 578 and 742 keV repor...