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11.
Shigeru Kumano Masashi Ihira Yasuo Maeda Misako Yamauchi Eiji Matsumoto Isao Matsuda 《Ecological Research》1990,5(2):221-235
Diatom assemblages of sediments obtained from three sites on Kushiro Moor were analyzed to investigate the Holocene sedimentary
history. The results showed that: 1) The Takkobu site was originally at the bottom of the paleo-Kushiro Bay, and after-wards
the paleo-Takkobu Lagoon developed, became sealed off, and changed to a freshwater lake. The succession to peat moor probably
began about 2000 yr B.P. at the Takkobu site. 2) The Tsurui site was originally at the bottom of the paleo-Kushiro Bay, then
changed to the paleo-Kushiro Lagoon and became peat moor as a result of the first Holocene regression, which finished about
3600 yr B.P. The site then returned to a brackish lake again, probably due to the second Holocene transgression between 3600
and 3000 yr B.P., thereafter passing through brackish lake and freshwater lake stages, and eventually becaming peat moor at
about 2000 yr B.P., 3) At the Chuo site, the second paleo-Kushiro Bay developed again as a result of the second Holocene transgression,
which finished about 3000 yr B.P. Thereafter, brackish or freshwater lakes, rivers, and then peat moor developed in the central
area of Kushiro Moor. 4) The second marine diatom zone (MD2 Zone), which indicates the second Holocene transgression, complete by about 3000 yr B.P., is detected only at the Chuo site
in the central area of Kushiro Moor. 相似文献
12.
A re-evaluation of the cytology of cat Pacinian corpuscles 总被引:1,自引:0,他引:1
Bryce L. Munger Yasuo Yoshida Shuichiro Hayashi Tokuji Osawa Chizuka Ide 《Cell and tissue research》1988,253(1):83-93
Summary The ultrastructure of cat mesenteric Pacinian corpuscles in cross and longitudinal sections has been examined. The terminal ends of lamellar cells of the inner core have been identified in longitudinal sections through the proximal portion of the inner core. These terminal bulbous expansions contain characteristic concentric membranes of rough endoplasmic reticulum and in some cases masses of oval membranous inclusions. The central axon as seen in cross section is oval in profile, having X-(short) and Y-(long) axes, and each axonal face is characterized by specializations of the axolemma. At the X-axis, the inner lamellae of the inner core tightly abut a smooth axolemma, with no intervening connective tissue matrix, in a manner reminiscent of a neuroepithelium. The axolemma of the Y-axis has numerous axonal spines (microspikes) that project into the cleft in the inner core. The extent of the axolemma having axonal spines can only be appreciated in longitudinal sections. The clefts contain a specialized connective tissue with elastic and collagen fibrils. The connective tissue compartment of fibers and matrix separating individual inner core lamellae is unique, in that it contains extremely thin collagen fibrils measuring approximately 15 nm in diameter. The diameter of collagen fibrils increases as the cleft is approached. Here the fibrils resemble typical endoneural collagen. 相似文献
13.
Solubilization and Characterization of Calcitonin Gene-Related Peptide Binding Site from Porcine Spinal Cord 总被引:1,自引:1,他引:0
Osamu Hiroshima Yoshihisa Sano Teruaki Yuzuriha Chiyuki Yamato Akira Saito Naomichi Okamura† Yasuo Uchiyama† Sadao Kimura † Katsutoshi Goto 《Journal of neurochemistry》1988,50(2):480-485
The binding site for calcitonin gene-related peptide (CGRP) was solubilized with 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate (CHAPS) in an active form from porcine spinal cord. 125I-labeled human alpha-CGRP (125I-CGRP) binding to the solubilized protein was determined by filtration using a GF/B glass filter. The maximal binding activity (approximately 60% of the crude membrane fraction) was obtained with 5 mM CHAPS. 125I-CGRP binding to the solubilized protein was of high affinity, saturability, and high specificity, having KD and Bmax values of 3.69 pM and 338 fmol/mg of protein, respectively. The binding activity was eluted in a single peak with a molecular mass of 400,000 daltons by gel filtration on TSK gel G4000SW. These results suggest that the solubilized protein may be responsible for the specific binding site. 相似文献
14.
The effects of isoproterenol on the release of alanine during perfusion with pyruvate and valine were studied in perfused hindlimbs from rats that had been kept for 5 or 20 days at 4 degrees C. In hindlimbs perfused with Krebs bicarbonate buffer in a flow-through mode, the rate of release of alanine during perfusion with 2 mM pyruvate plus 5 mM valine was 250 nmol.min-1.leg-1, a rate that is comparable with that reported in hindlimbs perfused with complex medium. Neither the pyruvate-stimulated nor valine plus pyruvate-stimulated rates of release of alanine changed after 20 days of exposure to cold. Isoproterenol inhibited the release of alanine during perfusion with pyruvate, with valine, and with valine plus pyruvate in hindlimbs from a control group of rats. However, in hindlimbs from cold-exposed groups, isoproterenol failed to inhibit the release of alanine during perfusion with valine plus pyruvate and stimulated the release of alanine during perfusion with valine. Aminooxyacetate inhibited the effects of valine, pyruvate, and isoproterenol. The results obtained suggested that cold exposure decreases the responses to isoproterenol of the mechanism of alanine release and causes an increased supply of alanine to the liver. 相似文献
15.
Motoki Tagami Kazuo Yamagata Hideaki Fujino Akiyoshi Kubota Yasuo Nara Yukio Yamori 《Cell and tissue research》1992,268(2):225-232
Summary In this study bovine aortic endothelial cells were co-cultured with astrocytes from fetal Wistar Kyoto rats. Endothelial cells growing on type-I collagen, development. Although some cells appeared to be mature, horseradish peroxidase penetrated within 1 min of incubation through the intercellular junctions of these endothelial elements maintained on type-I collagen. In contrast, endothelial cells on type-IV collagen, co-cultured with astrocytes, were well developed; their intercellular junctions were well established, and plasmalemmal vesicles reduced in number. As a result, horseradish peroxidase was unable to penetrate through the endothelial cells grown on type-IV collagen and co-cultured with astrocytes because of the reduced extent of the junctional and vesicular transport. These findings reveal that (1) type-IV collagen is essential for the differentiation of endothelial cells, (2) endothelial cell-astrocyte interactions occur during co-culture, and (3) endothelial permeability depends on astrocyte-produced factors, in addition to type-IV collagen. 相似文献
16.
Yasuo Ezaki 《Ecological Research》1992,7(1):63-70
Foraging habitat selection of breeding great reed warblers was studied at a shore of Lake Biwa. The foraging grounds of parent
warblers during the nesting period were not restricted to the breeding territory of the reed marsh, their nestling habitat.
The paddy field outside the reed marsh was used communally by them throughout the breeding season. Females with early stage
nestlings did not visit the paddy field whereas when nestlings were older than 3 days, more than half of their total food
was collected there. Females with nests adjacent to the paddy field tended to exploit the paddy field more often than those
with nests distant from it. Monogamously mated females tended to exploit the paddy field more often than polygynously mated
females. Food collected in the paddy field was larger than that in the reed marsh and parent birds were prepared to travel
longer distances to exploit the rich source of food in the paddy field. The importance of the communal foraging ground outside
the reed marsh as a background of the polygynous mating system of this species is discussed. 相似文献
17.
Masaaki Takeshita Seiji Nakamura Fujio Makita Susumu Ohwada Yukio Miyamoto Yasuo Morishita 《Biotherapy》1992,4(2):139-145
We examined whether orally administered RBS (rice bran saccharide), prepared from rice bran by hot water extraction, increases immunocompetence, inhibits gastrointestinal carcinogenesis with N-ethyl-N-nitro-N-nitrosoguanidine (ENNG) or shows an antitumor effect. After the administration of RBS, phytohemagglutinin (PHA)- and pokeweed mitogen (PWM)-stimulated blastogenesis of lymphocytes derived from the mesenteric lymph nodes and peripheral blood was enhanced, and the helper/ suppressor T-cell ratio was elevated, and migration activity of peritoneal macrophages was also increased in rats treated continuously with ENNG. ENNG-induced gastrointestinal carcinomas were observed in 43% of those administered RBS (ENNG-RBS) as compared with 88% in the control (ENNG) and 94% in the prednisolone (PRD) group (ENNG-PRD). The 12-month survival rate of rats bearing gastrointestinal cancer was 58% in the ENNG-RBS group as compared with 25% in the ENNG group and 15% in the ENNG-PRD group. RBS prevented the reduction in immunocompetence in the course of carcinogenesis, suppressed carcinogenesis, and prolonged the survival of rats with gastrointestinal cancer. Antitumor activities of RBS are thought to be a kind of host mediated action. The growth inhibition ratio of transplantable ENNG-induced cancer in Wistar rats was 42.1% in the RBS and 51.8% in the 5-FU group. Since little is known about the potent antitumor activity of -glucan, it would be interesting to consider the relationship between the structure and the biological activities of polysaccharides. 相似文献
18.
Keisuke Yamano Masatomo Tagawa Evelyn Grace de Jesus Tetsuya Hirano Satoshi Miwa Yasuo Inui 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1991,161(4):371-375
Summary To clarify the hormonal regulation of metamorphosis of the conger eel (Conger myriaster), changes in whole body concentrations of thyroid hormones, thyroxine (T4) and triiodothyronine (T3), and cortisol during metamorphosis were examined, as well as the changes in the histological activity of the thyroid gland. In larvae before metamorphosis, T4 and T3 levels were less than 5 and 0.15 ng·g-1 respectively. Levels of T4 increased to about 30 ng·g-1 during early metamorphosis, and decreased subsequently. Levels of T3 increased gradually in early metamorphosis, and then increased abruptly to about 2.0 ng·g-1 in late metamorphosis. Before metamorphosis, cortisol levels of the leptocephali less than 11 cm in total length were greater than 200 ng·g-1. Cortisol levels decreased rapidly in larger premetamorphic leptocephali, and low levels were maintained throughout the metamorphic period. Histological observation revealed an activation of the thyroid gland in early metamorphosis; thyroid follicle epithelial cells became columnar and their nuclei larger. Active uptake of colloid by these cells and intensive vascularization of the gland were also observed. By the end of metamorphosis, follicle epithelial cells became squamous, indicating a low level of glandular activity. These results suggest that thyroid hormone plays an important role in regulation of conger eel metamorphosis.Abbreviations
AL
anal length
-
TL
total length
-
T
3
triiodothyronine
-
T
4
thyroxine 相似文献
19.
Association of Lps gene with natural resistance of mouse macrophages against Legionella pneumophila 总被引:3,自引:0,他引:3
Shin-ichi Yoshida Yoshitaka Goto Hiroshi Miyamoto Hironobu Fujio Yasuo Mizuguchi 《FEMS microbiology letters》1991,89(1):51-56
We have cloned a 1.6-kb region of chromosomal DNA from Thermoplasma acidophilum into Escherichia coli using as a probe part of the Methanococcus vannielii fus-gene. The sequence of the clone was highly homologous to part of the corresponding Methanococcus vannielii gene. By chromosome walking, a 4.7-kb EcoRI fragment containing the complete gene was isolated. Nucleotide sequencing revealed an open reading frame of 2196 nucleotides. The deduced amino acid sequence contains the known peptide sequence around the ADP-ribosylation site of T. acidophilum elongation factor 2, which unequivocally confirms that the fus-gene has been cloned. The amino acid sequence was compared to that of hamster and E. coli, as well as to known archaebacterial EF-2 sequences. 相似文献
20.
Isolation and Identification of α-(γ-Aminobutyryl)-Hypusine 总被引:2,自引:2,他引:0
A new dipeptide, alpha-(gamma-aminobutyryl)-hypusine, was identified in bovine brain. This compound was isolated from trichloroacetic acid-soluble fraction of bovine brain with five steps of ion-exchange chromatography. Its structure was postulated by routine chemical analyses and determined by synthesis. The amount of the compound isolated from 1.2 kg of bovine brain was 870 nmol. 相似文献