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排序方式: 共有319条查询结果,搜索用时 15 毫秒
81.
Yuou Teng Katsuya Iuchi Eriko Iwasa Shinya Fujishiro Yoshitaka Hamashima Kosuke Dodo Mikiko Sodeoka 《Bioorganic & medicinal chemistry letters》2010,20(17):5085-5088
Chaetocin, a natural product isolated from Chaetomium species fungi, was reported to have various biological activities, including antitumor and antifungal activities. Recently, we reported the first total synthesis of chaetocin and its derivatives. Here, we examined the cell-death-inducing activity of these compounds in human leukemia HL-60 cells. The unnatural enantiomer of chaetocin (ent-chaetocin) was more potent than chaetocin, and was found to induce apoptosis through the caspase-8/caspase-3 activation pathway. 相似文献
82.
83.
84.
Suzuki J Kato A Maeda N Hashimoto C Uchikoshi M Mizutani T Doke C Matsuzawa T 《Primates; journal of primatology》2003,44(3):273-280
We examined growth changes in concentrations of plasma insulin-like growth factor-1 (IGF-1) and testosterone, and somatometric
parameters in two captive male agile gibbons from birth to about 4 years of age, to examine the evolution of growth patterns
in primates. Plasma IGF-1 concentrations in agile gibbons generally increased with age with values ranging from 200 to 1,100 ng/ml.
The growth profiles in plasma IGF-1 in the gibbons were similar to those reported for chimpanzees. The highest concentrations
of plasma testosterone (230 and 296 ng/dl) were observed within the first 0.3 years from birth, then the concentrations rapidly
decreased and fluctuated below 100 ng/dl. Continuously higher IGF-1 concentrations were observed after 2.6 and 3.5 years of
age. The profiles of plasma testosterone in these gibbons also resembled those of other primates including humans. However,
their plasma testosterone levels in both neonate and adult stages (60 ng/dl) were lower than those reported for macaques and
chimpanzees of respective stages. The obtained growth profiles of plasma IGF-1 and testosterone suggest that the adolescent
phase starts around 2.6 or 3.5 years of age in male agile gibbons. The growth trend in many morphological parameters including
body weight showed a linear increase without a significant growth spurt at approximately the onset of puberty. Head length
and first digit length had reached a plateau during the study period. Brachial index, which indicates the relative length
of forearm to upper arm, significantly increased gradually through the growth period. This result indicates that forearm becomes
relatively longer than the upper arm with growth, which may be an evolutionary adaptation for brachiation. 相似文献
85.
Mizutani C Tohyama Y Miura Y Hishita T Nishihara T Yamamura H Ichiyama S Uchiyama T Tohyama K 《Biochemical and biophysical research communications》2002,297(3):664-671
A human megakaryoblastic cell line, CMK, was treated with 12-o-tetradecanoylphorbol-13-acetate (TPA) for differentiation-induction. We examined TPA-induced activation of the MEK1-ERK1/2 pathway in the 100,000g Triton X-insoluble fraction of CMK cells as the membrane skeleton and researched the relation of the MEK1-ERK1/2 activation with integrin expression. We found that this activation was divided into two phases: the first activation occurred transiently in the membrane skeleton fraction of the suspended cell status and diminished after 1h; and the second sustained activation was maintained by cell adhesion. TPA-treated CMK cells revealed increased expression of integrins alphaIIb and beta3 only when the cell adhesion persisted, regardless of the difference of culture substratum. Sustained activation of the MEK1-ERK1/2 pathway is generated in the membrane skeleton by continuous cell adhesion and seems to be essential to TPA-induced megakaryocytic differentiation of CMK cells. 相似文献
86.
Each of 284 strains of Helicobacter pylori which had been isolated in Japan was shown, by use of the polymerase chain reaction (PCR), to be positive for the vacA genes. The amplified vacA genes generated by PCR were classified into six classes (five for the clinical isolates, and one which corresponded to the standard strains). Endoscopic analysis revealed that cases of gastritis were most likely to be associated with class D, while none were associated with class A. The patterns of products of PCR obtained from the Japanese isolates were compared with theoretical patterns derived from sequences of vacA which had been reported previously. The nucleotide sequences of amplified fragments of vacA from representative strains in each class were determined and compared with those of previously reported vacA genes. 相似文献
87.
Yamanaka A Imai H Adachi M Komatsu M Islam AT Kodama I Kitazawa C Endo K 《Zoological science》2004,21(10):1049-1055
Diapause pupae of Papilio xuthus show color polymorphism, represented by diapause-green, orange, and brownish-orange types that are each associated with specific pupation sites. We investigated the role of the site of pupation on the induction of the development of orange types (or brownish-orange types), and the endocrine mechanism underlying the control of color polymorphism in short-day pupae. All short-day larvae of the wandering stage developed into orange or brownish-orange type pupae when they were placed in rough-surfaced containers after gut-purge. Utilizing a pharate pupal ligation between the thorax and abdomen, the endocrine mechanism underlying the control of color polymorphism was shown to involve a head-thorax factor (Orange-Pupa-Inducing Factor: OPIF) that induced orange types in short-day pupae. OPIF was bioassayed using the ligated abdomens of short-day pharate pupae. OPIF was extractable with 2% NaCl solution from 5th-instar larval ganglia complexes following the mesothoracic complex (TG(2,3)-AG(1-7)), but it could not be extracted with either acetone or 80% ethanol solution. OPIF may not exist in the brains of day-0 pupae or in brain-subesophageal ganglion and prothoracic ganglion complexes of 5th-instar larvae. The short-day pharate pupae responded to OPIF in a dose-dependent manner. 相似文献
88.
89.
Saito M Yamanaka A Masaki H Nishijima A Harada Y Kitazawa C Abe H Watanabe M Endo K 《Zoological science》2005,22(11):1259-1263
The silken girdles of pupae of the swallowtail butterfly Atrophaneura alcinous show black and white color diphenism. Field observations revealed that all pupae observed on non-food plants and the leaves and stems of the larval food plant Aristolochia debilis were classified as a silken girdle of a black type, while a large portion of pupae pupating on the twigs and trunks of cherry trees in close proximity to A. debilis were classified as a silken girdle of a black type. Additionally, all pupae observed on the surfaces of artificial objects in areas where there are no surrounding plants or trees were classified as a silken girdle of a white type. We demonstrated the effect of day length and the texture, light, plant odor and humidity of pupation sites on the coloration of the silken girdle in A. alcinous. Regardless of long-day or short-day day length conditions, light conditions of constant light or dark, or the presence of a plant odor of A. debilis as environmental cues, all larvae placed at over 80% relative humidity (R.H.) developed into pupae with a silken girdle of a black type. However, all larvae developed into pupae with a silken girdle of a white type when R.H. was below 75%. Furthermore, when pupae with a silken girdle of a white type were transferred to conditions of 90% R.H. within 24 hr of pupation, the white color of the silken girdle changed into a black type within 24 hr of the transfer. The present data suggest that the induction of a black coloration of the silken girdle in A. alcinous requires a R.H. of approximately 80% or more as an environmental factor. 相似文献
90.
Chisato Hamashima Kazuei Ogoshi Mikizo Okamoto Michiko Shabana Takuji Kishimoto Akira Fukao 《PloS one》2013,8(11)