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11.
Kinetics of the change of photosystem (PS) composition in cyanobacteriainduced by chromatic light were studied in relation to cellproliferation. The study was made for two unicellular strains,Synechococcus NIBB 1059 and Synechocystis (Aphanocapsa) PCC6714. We found that (1) the change to a higher or lower PS I/IIratio was due to acceleration or suppression of apparent PSI formation, and (2) it progressed on a similar time scale tothat of the cell proliferation. The apparent rate constant ofthe change in the PS I/II ratio was proportional to that ofcell proliferation, µ, when this was low, but at highvalues of µ the increase in the rate constant of the changein the PS I/II ratio became smaller, causing a deviation fromthe linear relationship. Results indicate that under autotrophicconditions, the photoregulated composition change occurs asa result of thylakoid development, which accompanies cell proliferation. (Received June 23, 1986; Accepted December 5, 1986) 相似文献
12.
J K Steele H Kawasaki V K Kuchroo M Minami J G Levy M E Dorf 《Journal of immunology (Baltimore, Md. : 1950)》1987,139(8):2629-2634
A monoclonal antibody (mAb), B16G, was raised from BALB/c mice immunized with affinity-purified T suppressor factors (TsF) specific for the murine mastocytoma P815. This mAb was found to bind to polyclonal TsF isolated from the spleens of tumor-bearing animals, and to the TsF released from a P815-specific T cell hybridoma. In this study, B16G was tested for its reactivity with TsF produced in the 4-hydroxy-3-nitrophenyl acetyl hapten system. The factors from three types of suppressor T cell hybridomas, each representing the immortalized analogues of the inducer T suppressor cell (Ts1), transducer suppressor cell (Ts2), and effector suppressor cell (Ts3) network populations, were tested. B16G was found to be reactive with two sources of TsF1 as assayed by enzyme-linked immunosorbent assay and delayed-type hypersensitivity bioassay. By contrast, TsF2 and TsF3 were nonreactive with B16G. These results indicate that B16G recognizes class-specific suppressor factor determinants, and that the transducer/effector factors of the network are apparently serologically distinct. Because the B16G mAb fails to recognize 4-hydroxy-3-nitro-phenyl acetyl-specific TsF3 that share idiotype-related determinants with TsF1 yet binds to TsF1 molecules that have interacted with antigen, the binding is apparently independent of the site of antigen recognition. Additionally, the results show that the tumor-specific TsF1 raised in one suppressor system share serologic determinants with anti-hapten TsF1 raised in another. 相似文献
13.
Takuo Yamakura Akio Hagihara Sukristijono Sukardjo Husato Ogawa 《Ecological Research》1987,2(3):215-227
The form of tropical trees was studied with reference to the production structure of the component individuals of a tropical
rain forest stand in Sebulu, East Kalimantan in Indonesian Borneo, since the production structure as a physical or bio-economical
basis of tree form still remains obscure in tropical rain forests. The pipe model theory successfully explained the crown
shapes of different trees, and its parameter, designated as specific pipe length, suggested an increase in the cost of leaf
mass growth with an increase in crown size. A mathematical model consisting of exponential functions of aboveground height
was applied for describing stem form, and its properties were examined through changes in its coefficients and by adopting
an assumption of the geometrical similarity of individual stem form as a criterion for comparing differences in stem form
among individual trees. Furthermore, the cost of buttersses was discussed using the relation between bole- and buttress weight
calculated from the mathematical model. 相似文献
14.
Junichi Ishihara Nagahiro Saijo Yasutsuna Sasaki Hidehiko Nakano Akira Ozaki Hidenobu Takahashi Masanori Sakurai Kazuhiko Nakagawa Masaaki Iigo Fumihiko Kanzawa Akio Hoshi Weon Seon Hong James R. Jett Terumi Takahashi 《Cancer immunology, immunotherapy : CII》1987,24(3):185-189
Summary The antitumor effect of recombinant human tumor necrosis factor (rH-TNF) on two clones of rat fibrosarcoma with different metastatic potential to lymph nodes was examined. The colony formation of clone A, which has high metastatic potential, was completely inhibited by continuous exposure to rH-TNF at 50 U/ml. In contrast, colony formation of clone G, which has low metastatic potential, was not inhibited by high concentrations of rH-TNF (10,000 U/ml). The inhibitory effect of rH-TNF on colony formation by clone A was also observed with a 1-h exposure to rH-TNF. This effect was time and concentration dependent, as determined by the colony assay, 3H-thymidine uptake assay, and 51Cr-release assay. 3H-thymidine and 3H-uridine uptake per cell of clone A exposed to rH-TNF was not decreased. This suggests that the mechanisms of the antitumor effect of rH-TNF were not due to inhibition of DNA and RNA synthesis of tumor cells. In vivo growth and lymph node metastases of clone A inoculated i.p. to Donryu strain rats were completely suppressed by 14 consecutive i.p. injections of 105 or 106 U/kg per day of rH-TNF. On the other hand the growth of clone G was not influenced by rH-TNF administration. 相似文献
15.
The medium of 12-day-old culturs of tobacco cells (Nicotianatabacum L., var Xanthi; line XD-6S) contain c.a. 160mg/literof protein, of which 14% of the constituent ami no acids werefound to be hydroxyproline. By sequential column chromatographiesand CsCl density-gradient centrifugation, a basic hydroxyproline-richglycoprotein was purified from the medium and found to havean amino acid composition typical of extensin; with a high levelof hydroxyproline (33mole%), tyrosine (13%), and lysine (14%).The glycoprotein contained 42% (w/w) of sugars, among whicharabinose was the major component (85%). The proportion of thisextensin in the proteins in the culture medium was estimatedto be much higher than that of arabino-galactan protein (about5 times higher) on a protein basis, with extensin comprisingbetween 25% and 41%, and probably about 37% of the proteinsin the medium. (Received September 19, 1988; Accepted December 26, 1988) 相似文献
16.
The changes of dominance rank among female Japanese monkeys of the Koshima group over a period of 29 years from 1957 were
studied. The dominance rank order was relatively stable in the early population growing phase, while large scale-changes of
dominance rank order occurred successively in the phase of population decrease brought about by the severe control of artificial
feeding after 1972. Nevertheless, the rank order of several females of the highest status was stable. Furthermore, the reproductive
success of these highest status females was high (Mori, 1979a;Watanabe et al., in prep.). Divergence of the dominance rank order fromKawamura's rules (Kawamura, 1958) was observed in the following respects: (1) Some females significantly elevated their rank depending on the leader
males. (2) If mothers died when their daughters were still juveniles or nulliparous, the dominance rank of some of these offspring
females was significantly lower than the mother's one. However 55% of daughters which lost their mothers at a young age inherited
the mother's rank. (3) Dominance among sisters whose mother had died when at least one of the daughters was under 6 years
old followed the rule of youngest ascendancy in 60% (Kawamura, 1958), and in 80% when both of the daughters were nulliparous at the mother's death.
The mean rate of aggressive interactions for each female with subordinates to her was calculated by dividing the total aggressive
interactions between the female in question and her subordinates by the number of subordinate females to the female in question.
A female which showed a high rate of aggressive interactions with her subordinates was categorized as an “Attacker”, and a
female showing a lower rate was categorized as a “Non-attacker”. Similarly, categories of “Attacked”, and “Non-attacked” were
distinguished by using the rate of aggressive interactions with dominant females. Several females which were once categorized
in one category in a year were repeatedly categorized in the same category over different years. The “Attacked” tended to
be females of higher rank, and “Non-attackers” tended to be females of lower rank. “The second-higher-status females”, were
“Attacked”, and their rank was unstable. In particular, females of lower rank within the lineage of the highest rank suffered
this kind of severe status. Most of the daughters of these females showed a sharp drop of rank, and died when they were still
at a young age, i.e. “the second-higher-status females” displayed low fitness. “Non-attackers” were significantly “Non-attacked”;
i.e. they were females which showed a non-social attitude. Females which underwent a drop of rank tended to be “Non-attackers”.
The most important factor which determined the females' rank was the memory of their dominance relations under the influence
of their mother [dependent rank (Kawai, 1958)] in their early life during development. This finding corresponds well with the results in baboons obtained byWalter (1980); the target females of aggressive interactions by adolescent females were determined by the rank of the mothers when
these adolescent females were born. 相似文献
17.
Cytosolic adenylate kinase catalyzes the synthesis of thiamin triphosphate from thiamin diphosphate 总被引:2,自引:0,他引:2
An attempt was made to purify a porcine skeletal muscle enzyme catalyzing the formation of thiamin triphosphate (TTP) from thiamin diphosphate (TDP), requiring ATP, Mg2+ and a cofactor (creatine). As the purification proceeded, the reaction requirements for ATP and creatine were lost and then a requirement for ADP was manifested. The activity responsible for TTP synthesis from TDP, ADP, and Mg2+ was found to be copurified with adenylate kinase [EC 2.7.4.3] activity, and was finally purified to a single band on SDS-PAGE. Antiserum obtained against the purified enzyme preparation inhibited both adenylate kinase activity and the TTP-synthesizing activity to exactly the same extent. These results indicate that adenylate kinase catalyzes TTP formation from TDP in vitro. 相似文献
18.
K Takagaki A Kon H Kawasaki T Nakamura M Endo 《Journal of biochemical and biophysical methods》1989,19(2-3):207-214
The present paper describes a fluorometric assay for galactosaminoglycan-degrading endo-beta-xylosidase, utilizing glycosaminoglycan chains bearing a 4-methylumbelliferyl group at the reducing terminus as a substrate. This fluorogenic substrate is synthesized by human skin fibroblasts cultured in the presence of a fluorogenic xyloside, 4-methylumbelliferyl-beta-D-xyloside. The assay is based on measurement of the fluorescence of 4-methylumbelliferone, enzymatically liberated from the synthetic substrate by endo-beta-xylosidase. We examined the applicability of the assay for analysis of endo-beta-xylosidase activity. 相似文献
19.
Primary structure of an N-linked sugar chain derived from glucoamylase of Rhizopus niveus 总被引:2,自引:0,他引:2
K Takegawa N Kawasaki S Iwahara K Yamamoto T Tochikura B Mikami Y Morita 《Biochimica et biophysica acta》1989,990(1):98-100
The primary structure of the N-linked sugar chain of Rhizopus niveus glucoamylase (major component) was investigated. The carbohydrate moiety was released from the polypeptide backbone by Flavobacterium sp. endo-beta-N-acetylglucosaminidase digestion. Studies using the method of exoglycosidase digestion of the fluorescent pyridylamino derivative, gel-permeation chromatography on Bio-Gel P-4 and 400-MHz 1H-NMR spectroscopy revealed that the most abundant structure is (Man)8-GlcNac-ol. 相似文献
20.
Yuzuru Mikami Sen Feng Yu Katsukiyo Yazawa Kazutaka Fukushima Akio Maeda Jun Uno Kiyoshi Terao Naoki Saito Akinori Kubo Ken -ichiro Suzuki 《Mycopathologia》1990,112(2):113-118
During our studies on toxic substances from clinically isolated Nocarida, a new isolate identified as Nocardia otitidiscaviarum from cutaneous nocardiosis was found to produce a toxic substance called HS-6 that had strong in vitro as well as in vivo toxicity. The mouse intraperitoneal LD50 value was 1.25 mg/kg and the ED50 value for L1210 cultured cells was 0.3 ng/ml. The structure of HS-6 was determined and found to belong to the 16-membered macrocyclic group with a molecular formula of C43H68O12. HS-6 also showed activity against pathogenic fungi such as Cryptococcus neoformans. 相似文献