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41.
Ming PX  Ti YL  Bulmer GS 《Mycopathologia》2006,161(4):225-228
Twenty percent of 1000 dairy cows were infected with Trichophyton verrucosum in a newly established dairy farm in western China. The disease was transmitted to 30 of 100 animal workers. The source of the outbreak is unknown but it is suspected that naïve cattle which were transported from Holland to China became infected after they arrived in Xinjiang province (West China) where the fungus is endemic in nature, prepuberty school children and various livestock.  相似文献   
42.
Silibinin, an effective chemo-preventive agent in various cancer types, suppresses cancer cell growth, but its effects on cancer stem-like cells (CSLCs) remain unclear. This study aimed to examine whether silibinin inhibited the development of CSLCs and disclose the underlying signaling. The colorectal cancer spheroid culture system was used for enriching CSLCs. The effects of silibinin on CSLCs were evaluated by counting sphere numbers, and calculating the percentage of CD133+ cells by flow cytometry and immunofluorescence both in the absence and presence of different concentrations of silibinin. The results showed the sphere number of CCS was 36 ± 9.6 after 15 days of CSLC enrichment in spheroid culture, and the percentage of CD133+ cells increased to 18 ± 6.4% compared to 3 ± 0.8% before enrichment. Treatment with silibinin reduced the sphere formation to 5 ± 3.3 and decreased the CD133+ percentage to 8 ± 2.3%. Interestingly, treatment of silibinin suppressed the activation of the AKT Ser473/mTOR pathway in spheroid culture through suppressing the activity of protein phosphatase 2Ac subunit (PP2Ac). In a xenograft tumor model, treatment with silibinin also inhibited tumor formation rate and tumor growth. Silibinin, which inhibits colon CSLCs self-renewal and sphere formation by suppressing the PP2Ac/AKT Ser473/mTOR pathway, may be a compound for developing new strategies in modulating CSLCs in cancer therapy.  相似文献   
43.
A nitrogen budget of mainland China with spatial and temporal variation   总被引:6,自引:0,他引:6  
The present study evaluated nitrogen (N) input and output in mainland China using updated data of temporally and spatially-based land use maps and statistical data at national and provincial scales. The total N inputs increased from 3,081 kg km?2 in 1985 to 5,426 kg km?2 in 2007. Chemical fertilizer dominated the N input and showed an increasing trend. Biological N fixation was the second important N input till 1990 and atmospheric deposition became the second most important source after that, accounting for 24.0% in 2007. There was no net N input through food/feed import in 1985, but it accounted for 3.5% of the total N input in 2007. According to a mass balance model, we assumed total N input equal to output. The results showed that more than half of the total N was denitrified or stored in the system. Ammonia volatilization accounted for 18.9–22.9% of the total N input, and N export to water bodies accounted for 17.9–20.7%. About 5.1–7.7% of the N input was emitted to the atmosphere through biomass burning. When calculated per unit area, total N input, N export to water bodies, denitrification and storage could be very well explained by human population density. Nitrogen input and major outputs were also positively related to per capita gross domestic product and the percentage of total land area used as cropland. The N budget is compared to that of some other countries and the environmental impacts of the N cycle is discussed.  相似文献   
44.
The population dynamics parameters of scaldfish, Arnoglossus laterna, from the Adriatic Sea were studied. Specimens ranging from 4.5 to 17.1 cm in total length were collected from commercial bottom‐trawl catches (2000–2006). Spawning from April through the end of August with a peak in May, A. laterna is one of the non‐target species usually present in mixed bottom trawl catches. The overall male to female ratio was 1.00 : 0.61. The oldest individual was 6 years of age. Length–weight relationships showed positive allometric growth (b = 3.36 for males and b = 3.39 for females). Parameters of the von Bertalanffy growth equation were: L= 17.3 cm; K = 0.258 per year; t0 = ?1.0026 year; R2 = 0.925. The relatively low value of total mortality (Z = 0.90) and relatively high value of constant rate of natural mortality (M = 0.64) was estimated. Presumed calculated fishing mortality (F = 0.26) and the consequently estimated exploitation ratio (E = 0.29) indicated no danger of an over‐exploitation of this species in the study area at the current level of fishing pressure. The low T max and correspondingly high M suggest that this small benthic predator plays an important role in the Adriatic ecosystem as a prey species for large benthic predators. However, the estimates include uncertainties and require further confirmation, especially with regard to natural mortality.  相似文献   
45.
The study was conducted during the experiment with 105-day isolation in experimental complex. In the present investigation we collected urine samples from 6 healthy volunteers. The physical activity, diurnal rhythm, temperature parameters and level of oxygen and carbon dioxide were controlled during the experiment. According to the program, food intake (electrolytes, water, calories, fat, carbohydrates, protein, vitamins, etc.) on each stage of experiment was normalized. All samples were analyzed using mass spectrometer of an ionic cyclotron resonance with transformation of Fure LTQ FT MS (Thermo) on the basis of the AMT-tags (accurate mass and time tags) approach. Among more than 20 000 we found out 690 proteotypical proteins and we identified about 600 urine proteins. For physiological interpretation of the proteome data we used computer systems ANDCell and ANDVisio. Clustering of proteins and application of these systems revealed proteins that are most closely associated with the regime of sodium intake, as well as build the network of their interactions.  相似文献   
46.
As a common protein modification, ubiquitination is used for regulating the fate of protein targets, notably in terms of stability. In recent years, it has emerged to play key roles in the regulation of plant defense responses. Given its flexibility and critical roles in signaling, primarily in the control of protein turnover, ubiquitination is probably targeting many major immune regulators for modification or degradation. In this review, we summarize the latest findings on how different components of the ubiquitination pathway are involved in NB-LRR R protein-mediated immunity.  相似文献   
47.
目的:通过对门静脉高压脾功能亢进大鼠药物诱导肝癌过程中进行脾脏切除,探讨门静脉高压脾功能亢进对大鼠肝癌发生率的影响。方法:将雌雄SD大鼠性别内分别分为对照组、脾亢组、脾亢切脾组,脾功能亢进大鼠模型采用门静脉缩窄术联合脾静脉结扎术进行制备,各组均予以DEN(二乙基亚硝胺)腹腔注射,按体重20mg/kg给药,每周3次,12周停药,14周处死。其中,脾亢脾切除组于给药第四周进行脾切除术,手术恢复期间持续给药。观察各组实验动物的肝脏大体变化及病理改变,计算成瘤率。结果:实际成瘤率显示脾亢组较对照组明显升高,而雄性脾亢切脾组的成瘤率较脾亢组有所降低。雌性脾亢切脾组成瘤率同脾亢组差异不明显。结论:门静脉高压脾功能亢进状态下进行脾切除,对于雄性能减低肝癌发生的风险,对于雌性的意义不大,给临床实际工作提供了新的思路。  相似文献   
48.
目的:研究内质网应激预处理对人肝细胞缺氧复氧损伤的保护作用。方法:将培养的人肝细胞分为4组:正常对照(C)组、细胞缺氧复氧损伤(H/R)组、内质网应激(ER)组、内质网应激预处理(ERP+H/R)组。收集各组细胞,以流式细胞仪检测细胞凋亡,Western-bloting及RT-PCR检测内质网应激特异蛋白GRP78表达水平,并通过透射电镜观察各组细胞超微结构改变。结果:ERP+H/R组细胞凋亡率明显低于H/R组(P<0.05),ER及ERP+H/R组GRP78蛋白表达明显高于H/R组(P<0.05)。结论:内质网应激预处理对肝细胞缺氧复氧损伤具有明显的保护作用,内质网应激特异性蛋白GRP78可能在肝细胞缺氧复氧损伤中作为一种关键性的保护蛋白出现。  相似文献   
49.
Chiou SH  Kao CL  Chen YW  Chien CS  Hung SC  Lo JF  Chen YJ  Ku HH  Hsu MT  Wong TT 《PloS one》2008,3(5):e2090
Atypical teratoid/rhabdoid tumor (AT/RT) is an extremely malignant neoplasm in the central nervous system (CNS) which occurs in infancy and childhood. Recent studies suggested that CD133 could be considered a marker for brain cancer stem-like cells (CSCs). However, the role of CD133 in AT/RT has never been investigated. Herein we report the isolation of CD133-positive cells (CD133(+)), found to have the potential to differentiate into three germ layer tissues, from tissues of nine AT/RT patients. The migration/invasion/malignancy and radioresistant capabilities of CD133(+) were significantly augmented when compared to CD133(-). The clinical data showed that the amount of CD133(+) in AT/RTs correlated positively with the degree of resistance to radiation therapy. Using cDNA microarray analysis, the genotoxic-response profiles of CD133(+) and CD133(-) irradiated with 10 Gy ionizing radiation (IR) were analyzed 0.5, 2, 6, 12 and 24 h post-IR. We then validated these microarray data and showed increased phosphorylation after IR of p-ATM, p-RAD17, and p-CHX2 as well as increased expression of BCL-2 protein in CD133(+) compared to CD133(-). Furthermore, we found that CD133(+) can effectively resist IR with cisplatin- and/or TRAIL-induced apoptosis. Immunohistochemical analysis confirmed the up-regulated expression of p-ATM and BCL-2 proteins in IR-treated CD133(+) xenotransgrafts in SCID mice but not in IR-treated CD133(-). Importantly, the effect of IR in CD133(+) transplanted mice can be significantly improved by a combination of BCL-2 siRNA with debromohymenialdisine, an inhibitor of checkpoint kinases. In sum, this is the first report indicating that CD133(+) AT/RT cells demonstrate the characteristics of CSCs. The IR-resistant and anti-apoptotic properties in CD133(+) may reflect the clinical refractory malignancy of AT/RTs and thus the activated p-ATM pathway and BCL-2 expression in CD133(+) could be possible targets to improve future treatment of deadly diseases like AT/RT.  相似文献   
50.
Chemotaxis, a means for motile bacteria to sense the environment and achieve directed swimming, is controlled by flagellar rotation. The primary output of the chemotaxis machinery is the phosphorylated form of the response regulator CheY (P~CheY). The steady-state level of P~CheY dictates the direction of rotation of the flagellar motor. The chemotaxis signal in the form of P~CheY is terminated by the phosphatase CheZ. Efficient dephosphorylation of CheY by CheZ requires two distinct protein-protein interfaces: one involving the strongly conserved C-terminal helix of CheZ (CheZC) tethering the two proteins together and the other constituting an active site for catalytic dephosphorylation. In a previous work (J. Guhaniyogi, V. L. Robinson, and A. M. Stock, J. Mol. Biol. 359:624-645, 2006), we presented high-resolution crystal structures of CheY in complex with the CheZC peptide that revealed alternate binding modes subject to the conformational state of CheY. In this study, we report biochemical and structural data that support the alternate-binding-mode hypothesis and identify key recognition elements in the CheY-CheZC interaction. In addition, we present kinetic studies of the CheZC-associated effect on CheY phosphorylation with its physiologically relevant phosphodonor, the histidine kinase CheA. Our results indicate mechanistic differences in phosphotransfer from the kinase CheA versus that from small-molecule phosphodonors, explaining a modest twofold increase of CheY phosphorylation with the former, observed in this study, relative to a 10-fold increase previously documented with the latter.  相似文献   
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