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991.
Baharuddin Ghani Masataka Takai N. Zul Hisham Noriaki Kishimoto A. K. Mohamed Ismail Tatsuo Tano Tsuyoshi Sugio 《Applied microbiology》1993,59(4):1176-1180
A Mo6+ -reducing bacterium (strain 48), which grew on medium supplemented with 200 mM Mo6+, was isolated from stream water obtained from Chengkau, Malaysia. The chemical properties of strain 48 conform to the characteristics of Enterobacter cloacae. Under anaerobic conditions in the glucose-yeast extract medium containing phosphate ion (2.9 mM) and Mo6+ (10 mM), the bacterium reduced Mo6+ to form molybdenum blue. Approximately 27% of Mo6+ added to the medium was reduced after 28 h of cultivation. The reduction of Mo6+ with glucose as an electron donor was strongly inhibited by iodoacetic acid, sodium fluoride, and sodium cyanide, suggesting an involvement of the glycolytic pathway and electron transport in Mo6+ reduction. NADH and N,N,N′,N′ -tetramethyl-p-phenylenediamine served as electron donors for Mo6+ reduction. When NADH was used as an electron donor, at first cytochrome b in the cell extract was reduced, and then molybdenum blue was formed. Sodium cyanide strongly inhibited Mo6+ reduction by NADH (5 mM) but not the reduction of cytochrome b in the cell extract, suggesting that the reduced component of the electron transport system after cytochrome b serves as an electron donor for Mo6+ reduction. Both ferric and stannous ions strongly enhanced the activity of Mo6+ reduction by NADH. 相似文献
992.
Seedling morphology was studied in 22 species ofLespedeza, of which six belong to subgenusMacroles-pedeza and 16 to subgenusLespedeza. Two seedling types were recognized: 1) those with opposite leaves at the first node; 2) those having the first and subsequent
leaves alternate. The two types are distinguished in the number of leaf primordia in the plumule of the seed: the opposite
type has two leaf primordia, but the alternate type has only one primordium. Most species exhibited one of the two types,
but rarely both types were observed in several species. In species having two types, one type always far outnumbers the other.
The opposite type was common in Asian species, while the alternate type was common in North American ones. Because seedlings
are of the opposite type inKummerowia which is the most closely related genus withLespdeza, the alternate type is considered to be apomorphic inLespedeza. The apomorphic seedling morphology is, there-fore, dominantly occurred in North American species ofLespedeza. This fact may be an evidence which suggests a monophyletic origin for North American species from an Asian ancesfor. 相似文献
993.
Tsuyoshi Yoneda 《Journal of plant research》1993,106(3):229-237
Architecture of evergreen broadleaf trees in evergreen warm-temperate and tropical forests was analyzed with a ratio (U/Ac) of total surface area of aboveground woody organs to leaf area (one-sided surface area) of each felled tree. The ratio,U/Ac, tended to decrease with the increasing ofdbh. There was little difference in a range of the ratio at eachdbh class between a warmtemperate forest and a tropical rainforest. The ratios of larger trees correlated with their relative
growth rates ofdbh among similar sized trees. Canopy trees tended to stop their growth at some value of a ratio, a threshold value being about
1.5, irrespective of forest types. The threshold value showed the critical condition that annual respiration of woody organs
of a tree consumed nearly all surplus production. On the basis of the pipe model, an ideal maximum tree height was considered
with the ratio, and was estimated at 110 m and 70 m in a tropical rainforest and a warm-temperate forest, respectively. 相似文献
994.
Resource partitioning of Calamoecia lucasi Brady and Boeckella triarticulata (Thomson) (Copepoda:Calanoida) in an Australian reservoir 总被引:2,自引:2,他引:0
Tsuyoshi Kobayashi 《Hydrobiologia》1993,254(1):35-42
In Lyell Reservoir the food niches of Calamoecia lucasi and Boeckella triarticulata appear to be substantially separated by food type and/or food size. Large B. triarticulata eat a wider size range of food particles and exhibit greater dietary richness and breadth than do the small C. lucasi, even though the dietary richness and breadth for the two calanoid species fluctuate through time. The dietary overlap is also variable but is generally low, ranging from 0.329–0.752 in terms of Schoener's index. 相似文献
995.
Akihide Nakao Tsuyoshi Watanabe Shigeo Taniguchi Motonao Nakamura Zen-Ichiro Honda Takao Shimizu Kiyoshi Kurokawa 《Journal of cellular physiology》1993,155(2):257-264
Prostaglandin (PG) F2α increased [3H]thymidine incorporation into quiescent NIH 3T3 cells, stimulated phosphoinositide breakdown, and raised intracellular Ca2+ concentration ([Ca2+]i) in a dose-dependent manner with ED50 values of 2.0 × 10?8 M, 4.6 × 10?8 M, and 7.5 × 10?8 M, respectively. The increase in [3H]thymidine incorporation with PGF2α was additive with that seen with epidermal growth factor (EGF) or insulin. The peak [Ca2+]i increase with PGF2α was still obvious in the absence of extracellular Ca2+ and was insensitive to islet activating protein (IAP) pretreatment. Membranes prepared from NIH 3T3 cells exhibited a specific binding for PGF2α, which was sensitive to GTPγS but not sensitive to IAP pretreatment. Xenopus laevis oocytes injected with NIH 3T3 cell mRNA between 18S and 28S rRNA fractionated by sucrose gradient, expressed a PGF2α-specific Cl? current when examined by voltage clamp. This Cl? current was also insensitive to IAP pretreatment and not affected by extracellular Ca2+ concentration ([Ca2+]o). These results indicate 1) that the NIH 3T3 cells expressed a specific PGF2α receptor which is linked to phosphoinositide-specific phospholipase C (PLC) activation and to mobilization of Ca2+ via an IAP-insensitive G-proteins(s), 2) that this PGF2α receptor may play an active role in the proliferation of NIH 3T3 cells, and 3) that this PGF2α receptor can be expressed in the oocyte system. © 1993 Wiley-Liss, Inc. 相似文献
996.
997.
Minoru Yoshida Masakatsu Fukumoto Tsuyoshi Kishimoto Yukio Yamamura Hidesuke Shimizu Osamu Sakai 《Biological trace element research》1993,36(3):219-227
The influence of essential metals, like zinc, selenium, and calcium, on the nephrotoxicity of cadmium was studied in primary
cultures of rat proximal tubular cells. Damage to kidney cells was assessed by measuring the release of lactate dehydrogenase
(LDH), γ-glutamyltranspeptidase (GTP), and β-N-acetylglucosaminidase (NAG) from cells into the medium and the cellular concentration of protein. Incubation with 200 μM cadmium in the presence of equivalent molar or lower concentrations of zinc and selenium showed greater release of LDH and
NAG than cadmium alone, indicating an enhanced effect. However, metallothionein (MT) induced by pretreatment with a nontoxic
concentration of zinc decreased significantly the release of enzyme from cells and elevated cellular protein levels in response
to MT levels. MT provided partial protection against the nephrotoxicity of cadmium. Decreased calcium levels in the incubation
medium also resulted in markedly increased release of LDH and NAG from cells exposed to cadmium and reduced cellular protein
levels. These findings suggest that variations in zinc and calcium intake may affect the development of cadmium-induced renal
dysfunction. 相似文献
998.
Hiromichi Nagasawa Hisato Kuniyoshi Rika Arima Tsuyoshi Kawano Tetsu Ando Akinori Suzuki 《Archives of insect biochemistry and physiology》1994,25(4):261-270
Two structurally related molecular species of pheromone biosynthesis activating neuropeptides (PBANs), PBAN-I and -II, were isolated from adult heads of the silkworm, Bombyx mori, and characterized. PBAN-I is a carboxyl-terminally amidated 33-residue peptide. Structure-activity relationship studies revealed that 1) its carboxyl-terminal pentapeptide is the smallest size showing activity, 2) the carboxyl-terminal amide is indispensable for activity, and 3) oxidation of three Met residues in PBAN-I to Met(O) (methionine sulfoxide) caused marked enhancement of activity, and the three Met(O) residues contribute equally to the enhancement of activity. Molecular design of PBAN analogs using a carboxyl-terminal hexapeptide showed that modification of the amino-terminal amino group brought about a dramatic increase in activity. This increase was presumed to be mainly due to the increased stability in hemolymph. PBANs share the common carboxyl-terminal sequence, -Phe-Xaa-Pro-Arg-Leu-NH2, with myotropic peptides isolated from locust and cockroach. Examination of cross-activity of these two groups of peptides revealed that PBAN and its analogs exhibited myotropic activity comparable to myotropic peptides, while myotropic peptides showed extremely high pheromonotropic activity. In B. mori, PBAN activates sex pheromone (bombykol) production presumably by promoting the reduction reaction from acyl to alcohol, which is the last step in the biosynthesis of bombykol. © 1994 Wiley-Liss, Inc. 相似文献
999.
Takahiro Yano Kiichiro Teruya Sanetaka Shirahata Junko Watanabe Kazuhiro Osada Hirofumi Tachibana Hideya Ohashi Eun-Ho Kim Hiroki Murakami 《Cytotechnology》1994,16(3):167-178
In order to enhance recombinant protein productivity in animal cells, we developed the oncogene activated production (OAP) system. The OAP system is based on the premise that oncogenes are able to enhance promoter activity. To this end, we constructed reported plasmids by fusing various promoters to the human interleukin-6 (hIL-6) cDNA, and the effector plasmids by inserting individual oncogenes, for example c-myc, c-fos, v-jun, v-myb and c-Ha-ras, downstream from the human cytomegalovirus immediate early (CMV) promoter. Results of transient expression experiments with BHK-21 cells suggest that the CMV promoter is the most potent promoter examined and that theras product is able to transactivate the -actin, CMV and SR promoters. Recombinant BHK-21 cells producing hIL-6 under the control of the CMV promoter were contransfected with theras oncogene and dihydrofolate reductase gene, then selected with 50 nM methotrexate to coamplify theras oncogene. We were able to rapidly establish a stable and highly productive clone which exhibited a 35-times higher production rate as compared to the control value. 相似文献
1000.
Kiyoaki Matsubayashi Momoki Hirai Tsuyoshi Watanabe Yoshiko Ohkura Ken Nozawa 《Primates; journal of primatology》1978,19(4):785-793
A female patas monkey (Erythrocebus patas) housed with two males of different species, Hamadryas baboon (Papio hamadryas), and vervet monkey (Cercopithecus aethiops pigerythrus), gave birth to a female offspring in a semi-open enclosure on June 11, 1975. Karyological analyses and electrophoretic examinations
were carried out in order to determine the real father of the hybrid. From the results of these observations it was concluded
that the father of the hybrid individual wasCercopithecus aethiops. Additionally, somatometric and hematological investigations were performed. 相似文献