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41.
42.
Y. Tomita V. Bilim M. Takeda K. Takahashi 《Apoptosis : an international journal on programmed cell death》1996,1(3):209-212
The integration of Fas/Apo-1 (CD95) by Fas ligand or anti-Fas antibody induces apoptosis, and this system plays a pivotal role for the lysis of target cells by cytotoxic T lymphocytes. Fas-mediated apoptosis is also increased by a prior incubation of Fas-bearing cells with interferon(IFN)-. Interleukin-1- converting enzyme (ICE) and/or CPP32, or other members of ICE family act as direct cell death executors downstream of this mechanism, and a tetrapeptide inhibitor of these cysteine proteases blocks Fas-mediated apoptosis. In this study, we examined the effect of IFN- on Fas-mediated apoptosis in ACHN cells. IFN- augmented apoptosis in a dose dependent manner and reached a plateau at 400 U/ml when exposed for 48 h before the end of culture. The kinetics revealed a significant increase in apoptosis after 24 h. Exposing ACHN cells to IFN- increased pro-ICE expression accompanied with a decrease of pro-CPP32. These results suggest that direct enhancement of ICE expression and/or upregulation of conversion of pro-CPP32 to active form increases Fas-mediated apoptosis by IFN- in ACHN cells. 相似文献
43.
Kadokawa H Minezawa M Yamamoto Y Takahashi M Shimada K Takahashi H Kariya T 《Theriogenology》1995,44(2):295-306
Heterosexual chimerism among singleton females produced by multiple nonsexed embryo transfer (MNET singleton females) was investigated using chromosome typing and PCR (polymerase chain reaction)-amplification of male-specific DNA (msDNA). Of the 22 animals tested, 21 were classified as normal by both methods (i.e., showing no male cells among 100 metaphase spreads in chromosome typing and being msDNA negative in PCR). No morphological abnormalities of the genital organs were observed among 19 MNET single females. One MNET singleton female was, however, classified as a freemartin by PCR (male-specific DNA positive), but it was classified as normal cytogenetically. This individual probably had a low degree of heterosexual chimerism, and it seems that the chimerism derived from MNET was difficult to diagnose by chromosome typing, although it was detectable by PCR. The genital organs of this individual (15-mo-old Aberdeen Angus) were normal in form (both external and internal) and size. However, a very small structure, resembling seminiferous tubule, was found in the left ovary. It may be concluded that most MNET singleton females are expected to have normal reproductive function. 相似文献
44.
The localization of the antigen for monoclonal antibody 9F11-B-E4 was clarified by immuno-electron microscopy. The antigens were localized on the mitochondria and Golgi bodies in the male germ cells and on the secretory granules of various glands cells in the penis bulb and subepidermal parenchymal tissue of Phagocata vivida. The results of the interspecific cross-reaction tests with seven other freshwater triclads showed that these secretory granules are species-specific. A positive interspecific reaction was showed with Dugesia (family Dugesiidae), but not with Polycelis within the same family Planariidae which suggests the position of Phagocata within the Planariidae needs to be reassesed. 相似文献
45.
D-Amino acid production from racemic amino acids by a microbial asymmetric degradation 总被引:1,自引:0,他引:1
To obtain D-amino acid from a mixture of racemic amino acids, Proteus vulgaris, having the ability of selective degradation of L-isomer in various DL-amino acids mixtures, was used as a biocatalyst. D-Isomer crystals of valine, leucine, isoleucine, histidine and ornithine were isolated at a good yield (25~41%) from the reaction mixture after 24~72 hours. 相似文献
46.
Shinichi Watanabe Masayoshi Osumi Takamitsu Ohnishi Eiko Ichikawa Hisashi Takahashi 《Histochemistry and cell biology》1995,103(6):425-433
In order to investigate the re-epithelialization process during wound healing, the hair on the back of guinea pigs was shaved and then excisional wounds were made through the entire thickness of the skin. Histological changes were observed and changes in the expression of different cytokeratin polypeptides were examined using an immunohistochemical technique. Immunohisto chemical study revealed that the proliferating and migrating keratinocytes expressed the same cytokeratins as the basal cells of normal epidermis. In addition, the entire epidermis of fairly remote areas from the edges of the wound where no thickening was observed showed a temporarily abnormal staining pattern. The suprabasal cells in the regenerating epidermis temporarily expressed cytokeratins not only specific for suprabasal cells but also specific for basal cells. The cytokeratins expressed in normal basal keratinocytes were also present in the thickened granular layers. These data indicate that the expression of cytokeratins in the epidermal keratinocytes (even in fairly remote areas from the wound edges) changes during wound healing, that the origin of the migrating keratinocytes from the remaining epidermis seems to be the basal cells in the epidermis, and that the appearance of keratohyalin granules is not related to changes in cytokeratin expression. 相似文献
47.
Varicella infection in a children's hospital: prevention by vaccine and an episode of airborne transmission 总被引:1,自引:0,他引:1
Varicella vaccine was used safely and effectively for preventing ward infection with varicella. Ward infection was experienced 34 times in 5 years between 1977 and 1982. During these ward infections, varicella developed in 4 of 142 patients who received vaccine, 21 of 47 patients who did not receive vaccine and 1 of 9 who received transfusion with vaccine-boostered blood. Of the 142 vaccinated patients, the four in whom varicella developed showed symptoms 3 to 10 days after vaccination, indicating that vaccination had been too late. Details of a ward infection with varicella by airborne transmission and its prevention by vaccination are presented. 相似文献
48.
Polyethylene glycol-modified catalase exhibits unexpectedly high activity in benzene 总被引:1,自引:0,他引:1
K Takahashi A Ajima T Yoshimoto Y Inada 《Biochemical and biophysical research communications》1984,125(2):761-766
Bovine liver catalase with molecular weight of 248,000, which consists of four subunits, was modified with 2,4-bis(o-methoxypolyethylene glycol)-6-chloro-s-triazine(activated PEG2). The modified catalase became soluble in organic solvents such as benzene by increasing the degree of modification of amino groups in the enzyme with activated PEG2. The enzymic activity of the modified catalase in benzene, in which 42% of the total amino groups were coupled with the modifier, was unexpectedly high in comparison with the activity of non-modified catalase in aqueous system. The absorption spectrum of the modified catalase in benzene showed the characteristic pattern of a haem protein with Soret band at 405 nm. The temperature-activity profile of the modified catalase in benzene was clarified and its activation energy was estimated to be 1900 cal/mol. 相似文献
49.
50.
Joseph S. Takahashi Michael Menaker 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1984,154(3):435-440
Summary The avian pineal gland contains a circadian pacemaker that oscillates in vitro. Using a flow-through culture system it is possible to measure melatonin production from very small subsections of an individual gland. We have used this technique to attempt to localize the oscillators in the pineal. Progressive tissue reduction did not affect the rhythmicity of cultured pineals. Multiple pieces (up to eight) from a single pineal all were capable of circadian oscillation — establishing directly that a pineal gland contains at least eight oscillators. All pineal pieces were responsive to light, and single light pulses shifted the phase of the melatonin rhythm. Because pieces equivalent to less than one per cent of the whole gland were rhythmic and because the capacity for oscillation was distributed throughout the gland, an individual pineal appears to be composed of a population of circadian oscillators. 相似文献