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排序方式: 共有1273条查询结果,搜索用时 46 毫秒
91.
92.
Haibin Kuang Hongying Peng Hong Xu Baoping Zhang Jing Peng Yi Tan 《Journal of molecular histology》2010,41(1):1-7
Uterine Natural Killer (uNK) cells are the most abundant lymphocyte population recruited in the uteri during murine and human
pregnancy. Previous investigation on uNK cells during mouse pregnancy focused more on its accumulation in postimplantation
periods, which were believed to play important roles in regulating trophoblast invasion and angiogenesis towards successful
placentation. However, by using recently developed methods of Dolichos biflorus agglutinin (DBA) lectin, a closer examination
during mouse preimplantation revealed that there were also dynamic regulations of uNK cell, suggesting a major regulation
by steroid hormones. Here we provide a detailed examination of uNK cells distribution during mouse early pregnancy by DBA
lectin reactivity, with emphasis on preimplantation period and its hormonal regulation profiles. Our results showed that uNK
precursor cells or its cell membrane specific components could be recruited in the uterus by estrogen or/and progesterone,
and the effects could be completely abolished by specific antagonists of their nuclear receptors (estrogen and progesterone
receptor). These results suggested that the preimplantation uterus, through concerted hormone regulation, could recruit uNK
precursor cell or its specific cellular component, which might be conducive for uterine receptivity and further uNK construction/function
during postimplantation. 相似文献
93.
Abstract Circadian mating rhythms, mating frequency, mating duration, and the effect of mating duration on fecundity and fertility in the cabbage beetle, Colaphellus bowringi were investigated in the laboratory. Mating occurred throughout the 24-h cycle but the majority of copulations occurred in the photophase with two apparent peaks, one at 8:00 and another at 16:00. Mating frequency observations for 10 consecutive days indicated that pre-mating period of C. bowringi was about 4 days, and pairs mated an average of 5 times per day and an average of 40 times during the first 10 days. There was a negative correlation between mating frequency and mating duration during the consecutive mating. The mean duration of the first copulation (136.24 ± 4.62 min) was significantly longer than those of the second (57.87 ± 2.03 min), third (53.05 ± 2.05 min) and fourth copulation (30.86 ± 2.98 min). Fecundity showed a slight increase with increasing mating duration but no significant difference among treatments. However, fertility was significantly influenced by the mating duration in this species. Mating of 20-min duration did not produce viable eggs. The mean percentage of fertile eggs with completed mating duration (204.43 ± 18.96 min, 56.75% fertile eggs) was significantly higher than those with 60 min (39.55%) and 30 min (17.91%) mating duration, suggesting that the longer mating duration might be associated with transfer of more sperm that are used to increase the fertility of eggs. 相似文献
94.
Background
Androgens bind to the androgen receptor (AR) in prostate cells and are essential survival factors for healthy prostate epithelium. Most untreated prostate cancers retain some dependence upon the AR and respond, at least transiently, to androgen ablation therapy. However, the relationship between endogenous androgen levels and cancer etiology is unclear. High levels of androgens have traditionally been viewed as driving abnormal proliferation leading to cancer, but it has also been suggested that low levels of androgen could induce selective pressure for abnormal cells. We formulate a mathematical model of androgen regulated prostate growth to study the effects of abnormal androgen levels on selection for pre-malignant phenotypes in early prostate cancer development. 相似文献95.
Holterman CE Le Grand F Kuang S Seale P Rudnicki MA 《The Journal of cell biology》2007,179(5):911-922
We identify here the multiple epidermal growth factor repeat transmembrane protein Megf10 as a quiescent satellite cell marker that is also expressed in skeletal myoblasts but not in differentiated myofibers. Retroviral expression of Megf10 in myoblasts results in enhanced proliferation and inhibited differentiation. Infected myoblasts that fail to differentiate undergo cell cycle arrest and can reenter the cell cycle upon serum restimulation. Moreover, experimental modulations of Megf10 alter the expression levels of Pax7 and the myogenic regulatory factors. In contrast, Megf10 silencing in activated satellite cells on individual fibers or in cultured myoblasts results in a dramatic reduction in the cell number, caused by myogenin activation and precocious differentiation as well as a depletion of the self-renewing Pax7+/MyoD− population. Additionally, Megf10 silencing in MyoD−/− myoblasts results in down-regulation of Notch signaling components. We conclude that Megf10 represents a novel transmembrane protein that impinges on Notch signaling to regulate the satellite cell population balance between proliferation and differentiation. 相似文献
96.
Lu Xiaofei Qin Zhangfen Lambers Hans Tang Songbo Kaal Joeri Hou Enqing Kuang Yuanwen 《Plant and Soil》2022,476(1-2):25-29
Plant and Soil - Silicon (Si) is a beneficial element for plants and plays important roles in the biogeochemical cycle of mineral elements. Yet, few studies have focused on the impact of nitrogen... 相似文献
97.
Zhu Qingjun Yang Yanyan Xiao Yanan Han Wenhui Li Xingyue Wang Wenda Kuang Tingyun Shen Jian-Ren Han Guangye 《Photosynthesis research》2022,152(2):193-206
Photosynthesis Research - Photosystem II (PSII) has a number of hydrogen-bonding networks connecting the manganese cluster with the lumenal bulk solution. The structure of PSII from... 相似文献
98.
99.
Xinqiong Huang Yujie Qian Hainan Wu Xiaoxue Xie Qin Zhou Ying Wang Weilu Kuang Lin Shen Kai Li Juan Su Liangfang Shen Xiang Chen 《The journal of histochemistry and cytochemistry》2015,63(2):88-98
Radiotherapy is the first-line treatment for all stages of cervical cancer, whether it is used for radical or palliative therapy. However, radioresistance of cervical cancer remains a major therapeutic problem. Consequently, we explored if E-cadherin (a marker of epithelial-mesenchymal transition) and osteopontin could predict radioresistance in patients with locally advanced cervical squamous cell carcinoma (LACSCC). Patients were retrospectively reviewed and 111 patients divided into two groups (radiation-resistant and radiation-sensitive groups) according to progression-free survival (PFS). In pretreated paraffin-embedded tissues, we evaluated E-cadherin and osteopontin expression using immunohistochemical staining. The percentage of patients with high osteopontin but low E-cadherin expression in the radiation-resistant group was significantly higher than those in the radiation-sensitive group (p<0.001). These patients also had a lower 5-year PFS rate (p<0.001). Our research suggests that high osteopontin but low E-cadherin expression can be considered as a negative, independent prognostic factor in patients with LACSCC ([Hazard ratios (95% CI) 6.766 (2.940, 15.572)], p<0.001). 相似文献
100.
Lin Wei Jiuxiang Gao Shumin Zhang Sijin Wu Zeping Xie Guiying Ling Yi-Qun Kuang Yongliang Yang Haining Yu Yipeng Wang 《The Journal of biological chemistry》2015,290(27):16633-16652
Cathelicidins are a family of gene-encoded peptide effectors of innate immunity found exclusively in vertebrates. They play pivotal roles in host immune defense against microbial invasions. Dozens of cathelicidins have been identified from several vertebrate species. However, no cathelicidin from marine reptiles has been characterized previously. Here we report the identification and characterization of a novel cathelicidin (Hc-CATH) from the sea snake Hydrophis cyanocinctus. Hc-CATH is composed of 30 amino acids, and the sequence is KFFKRLLKSVRRAVKKFRKKPRLIGLSTLL. Circular dichroism spectroscopy and structure modeling analysis indicated that Hc-CATH mainly assumes an amphipathic α-helical conformation in bacterial membrane-mimetic solutions. It possesses potent broad-spectrum and rapid antimicrobial activity. Meanwhile, it is highly stable and shows low cytotoxicity toward mammalian cells. The microbial killing activity of Hc-CATH is executed through the disruption of cell membrane and lysis of bacterial cells. In addition, Hc-CATH exhibited potent anti-inflammatory activity by inhibiting the LPS-induced production of nitric oxide (NO) and pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6. Hc-CATH directly binds with LPS to neutralize its toxicity, and it also binds to Toll-like receptor 4 (TLR4/MD2 complex), which therefore inhibits the binding of LPS to TLR4/MD2 complex and the subsequent activation of LPS-induced inflammatory response pathways. Taken together, our study demonstrates that Hc-CATH, the first cathelicidin from sea snake discovered to have both antimicrobial and anti-inflammatory activity, is a potent candidate for the development of peptide antibiotics. 相似文献