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91.
Kazuko Wada Shintaro Nomura Eiichi Morii Yukihiko Kitamura Yasuko Nishizawa Akira Miyake Nobuyuki Terada 《The Journal of steroid biochemistry and molecular biology》1996,59(5-6):367-375
To examine the roles played by transforming growth factors (TGF)-β1, -β2, -β3, and TGF-β type II receptors in the induction of apoptosis in the mouse uterine epithelium after estrogen deprivation, we investigated the expression of their mRNAs and the mRNA of sulfated glycoprotein-2 (SGP-2). Pellets containing 100 μg estradiol-17β (E2) were implanted into ovariectomized mice and removed four days later. Apoptotic indices (percentage of apoptotic cells) of both luminal and glandular epithelia increased after E2 pellets were removed, but administration of progesterone (P), 5-dihydrotestosterone (DHT), or continued implantation of E2 pellets suppressed this increase. Levels of mRNAs of TGF-β1, -β2, and -β3, and SGP-2 did not increase after estrogen deprivation. However, estrogen deprivation caused a gradual increase in the level of TGF-β type II receptor mRNA, and its level increased about six-fold six days later. Moreover, E2, P, and DHT markedly decreased the level of TGF-β type II receptor mRNA. In situ hybridization demonstrated that mRNAs of TGF-β1, -β2, -β3 and TGF-β type II receptor were localized to the epithelium. Exogenous administration of TGF-β1 into the uterine stroma induced apoptosis in the epithelium, a finding that suggests that signals produced by TGF-βs can induce apoptosis. Therefore, the present results suggest that increased sensitivity of uterine epithelial cells to TGF-βs, as demonstrated by an increase in TGF-β type II receptor mRNA, is involved in the induction of apoptosis after estrogen deprivation, although signals produced by TGF-βs do not appear sufficient to induce apoptosis. 相似文献
92.
93.
A 19-kb CpG Island Associated with Single-minded Gene 2 in Down Syndrome Chromosomal Region 总被引:1,自引:0,他引:1
Osoegawa Kazutoyo; Okano Saishi; Kato Yasutake; Nishimura Yukinobu; Soeda Eiichi 《DNA research》1996,3(3):175-179
To help in isolating the genes involved in Down syndrome, wesought CpG islands in 4 Mb cosmid/PAC contigs spanning mostof the 21q.22.2 band using seven rare cutting enzymes. A strikingfeature was observed upstream of hSIM2 where at least 41 rare-cuttingsites were clustered within a 20-kb region. To investigate thestructure of the cluster, a cosmid containing hSIM2 was submittedto shotgun sequencing. Sequence analysis revealed that the clusterwas a long CpG island extending 19, 128 nucleotides which includesin the first and second exons of hSIM2. Taken together withour observation in which the CpG islands were concentrated within1.2 Mb around hSIM2, we propose that this region functions asan R-band, and the cluster provides a unique element for markingof DNA for the spatial and temporal expression of the hSIM2locus. 相似文献
94.
95.
Summary Intercolonial differences in raiding activity were investigated in the field on 9 colonies of the slavemaking antPolyergus samurai. Duration of raiding season, the mean start time of the first raiding trip in a day, the mean speed of outbound and inbound trips, and the mean distance to target nests varied significantly among colonies. The variance in start time of raiding was correlated with that in soil temperature and diurnal change pattern in soil temperature at the nest sites. The speed of trips and the first day with trips in the season also correlated with soil temperature at the nest site. Simple environmental factors well explained the observed variances in raiding activity among colonies. Therefore, raiding behaviour ofP. samurai seemed to be a stereotyped behaviour that is regulated through simple environmental factors. 相似文献
96.
Hasegawa Ryo; Maruyama Akiko; Sasaki Hiroshi; Tada Tomoko; Esashi Yohji 《Journal of experimental botany》1995,46(5):551-556
A possible involvement of ß-cyanoalanine synthase(CAS: EC 4.4.1.9
[EC]
) in germination processes of seeds was demonstratedusing pre-soaked upper seeds of cocklebur (Xanthium pennsylvanicumWallr.). Pretreatment in anoxia not only with KCN but also cysteine,as the substrates for CAS, stimulated the subsequent germinationof cocklebur seeds in air. However, the effect of cysteine wasmanifested even in air when applied together with C2H4, andits effect was further enhanced in combination with KCN. Thegermination-stimulating effect of KCN was intensified by C2H4only when 02 was present. In contrast, serine, another substrateof CAS, was effective in air only when combined with C2H4 and/orKCN. The addition of cysteine greatly reduced the cyanogenicglycoside content of seeds, but increased HCN evolution. Onthe other hand, glutathione did not have any effect on cockleburseed germination, HCN evolution or bound cyanogen content, suggestingthat cysteine is not acting as a reducing reagent. It is suggestedthat CAS regulates the process of cocklebur seed germinationby the dual action of enlarging the pool of amino acids andsupplying sulphydryl bases, the latter being more determinatelyimportant. Serine is effective only via the former action, whilecysteine would act via both. Key words: Cyanide, cyanogenic glycoside, ß-cyanoalanine synthase, seed germination, Xanthium pennsylvanicum 相似文献
97.
Seitaro Ohkuma Hidehiko Narihara Masashi Katsura Takeshi Hasegawa Kinya Kuriyama 《Journal of neurochemistry》1995,65(3):1109-1114
Abstract: The functional significance of peroxynitrite in the release of [3 H]GABA induced by nitric oxide (NO) liberated from NO generators was investigated using cerebral cortical neurons in primary culture. NO generators such as sodium nitroprusside (SNP) and S -nitroso- N -acetylpenicillamine (SNAP) increased [3 H]GABA release in a dose-dependent manner. These increases in [3 H]GABA release were significantly inhibited by hemoglobin, indicating that those NO generators evoke the release of [3 H]GABA by the formation of NO. Two types of superoxide scavengers, Cu2+ /Zn2+ superoxide dismutase and ceruloplasmin, significantly reduced the increase in [3 H]GABA release induced by both SNP and SNAP, which assumes that NO requires superoxide to induce [3 H]GABA release from the neurons. In addition, synthesized peroxynitrite induced a dose-dependent increase in [3 H]GABA release from the neurons. These results indicate that NO-induced [3 H]GABA release is mediated by peroxynitrite formed by the reaction of NO with superoxide. 相似文献
98.
Hideyuki Yamamoto Futosi Arakane Tsunehiko Ono Kazuhiro Tashima Eiichi Okumura Keisuke Yamada Shin-ichi Hisanaga Kohji Fukunaga Takeo Kishimoto Eishichi Miyamoto 《Journal of neurochemistry》1995,65(2):802-809
Abstract: Excitatory amino acid (EAA) neurotransmitters may play a role in the pathophysiology of traumatic injury to the CNS. Although NMDA receptor antagonists have been reported to have therapeutic efficacy in animal models of brain injury, these compounds may have unacceptable toxicity for clinical use. One alternative approach is to inhibit the release of EAAs following traumatic injury. The present study examined the effects of administration of a novel sodium channel blocker and EAA release inhibitor, BW1003C87, or the NMDA receptor-associated ion channel blocker magnesium chloride on cerebral edema formation following experimental brain injury in the rat. Animals (n = 33) were subjected to fluid percussion brain injury of moderate severity (2.3 atm) over the left parietal cortex. Fifteen minutes after injury, the animals received a constant infusion of BW1003C87 (10 mg/kg, i.v.), magnesium chloride (300 µmol/kg, i.v.), or saline over 15 min (2.75 ml/kg/15 min). In all animals, regional tissue water content in brain was assessed at 48 h after injury, using the wet weight/dry weight technique. In saline-treated control animals, fluid percussion brain injury produced significant regional brain edema in injured left parietal cortex ( p < 0.001), the cortical area adjacent to the site of maximal injury ( p < 0.001), left hippocampus ( p < 0.001), and left thalamus ( p = 0.02) at 48 h after brain injury. Administration of BW1003C87 15 min postinjury significantly reduced focal brain edema in the cortical area adjacent to the site of maximal injury ( p < 0.02) and left hippocampus ( p < 0.01), whereas magnesium chloride attenuated edema in left hippocampus ( p = 0.02). These results suggest that excitatory neurotransmission may play an important role in the pathogenesis of posttraumatic brain edema and that pre- or post-synaptic blockade of glutamate receptor systems may attenuate part of the deleterious sequelae of traumatic brain injury. 相似文献
99.
Expression of gicerin in development, oncogenesis and regeneration of the chick kidney 总被引:1,自引:0,他引:1
100.
Virulent and avirulent Rhodococcus equi infection in T-cell deficient athymic nude mice: pathologic, bacteriologic and immunologic responses 总被引:1,自引:0,他引:1