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201.
Established populations of Pseudodacrylogyrus anguillae are reported from eels in England for the first time. Prevalence and abundance peak in late summer in all three localities and the parasite overwinters at low levels on eels. 相似文献
202.
Chemically sulfated polysaccharide (S-GAP-P) was derived from water-insoluble polysaccharide of Grifola frondosa mycelia. In this research, we investigated the anticancer effects of S-GAP-P and its combination with 5-fluorouracil (5-FU) on human gastric carcinoma SGC-7901 cells. Results showed that S-GAP-P distinctly inhibited SGC-7901 cells growth in a dose-dependent manner and induced cell apoptosis evidenced by characteristic DNA ladder and sub-G0/G1 peak. Furthermore, the combination of S-GAP-P (10–50 μg/ml) with 1 μg/ml 5-FU resulted in a significant inhibition on SGC-7901 cells growth, meaning the beneficial interaction between the two drugs. All these results suggested that S-GAP-P has evident anticancer activity through apoptotic induction and could significantly accelerate the anticancer activity of 5-FU. 相似文献
203.
Fanchang Zeng Xianlong Zhang Shuangxia Jin Lei Cheng Shaoguang Liang Lisong Hu Xiaoping Guo Yichun Nie Jinglin Cao 《Plant Cell, Tissue and Organ Culture》2007,90(1):63-70
We conducted a systematic assessment and comparative study on the biochemical and cellular characteristics of cultured cotton
cells during the entire process of somatic embryogenesis (SE). All staged cultures were widely investigated in this assay.
Cell and tissue ectogenesis manipulation combined with flow cytometry (FCM) was employed to cellular study during the whole
totipotency process of dedifferentiation and redifferentiation. We identified two phases of chromatin decondensation during
the dedifferentiation and redifferentiation. At the same time, sharp increase in the ratio of indoleacetic acid (IAA), isopentenyladenosine
group (iPAs) at the same stage of cell dedifferentiation and redifferentiation process serve as distinct biochemical maker
of dedifferentiation and SE initiation with the unique feature. Our results suggest the two phases of chromatin reorganization
associated with endogenous auxin/cytokinin dynamic activity may underlie dedifferentiation and redifferentiation during the
entire SE process in cotton. 相似文献
204.
A hydroponic trial was conducted to investigate effects of molybdenum (Mo) on ascorbate-glutathione cycle (AsA-GSH cycle)
metabolism in Chinese cabbage (Brassica campestris L. ssp. pekinensis). Mo was applied at four rates: 0, 0.01, 0.15 and 1.5 mg l−1. The concentrations of ascorbate, dehydroascorbate, reduced- and oxidized- glutathione, and activities of five key enzymes
in the AsA-GSH cycle were studied. The results showed that appropriate Mo application increased the fresh weight of Chinese
cabbage, but excess application of Mo (1.5 mg l−1 Mo) decreased the fresh weight. Total ascorbate and reduced ascorbate concentrations in the Chinese cabbage increased with
Mo application rates. Although no significant differences existed in DHA concentration between the different Mo regimes, but
it has an increase trend with the 0.01 mg l-1 Mo treatment, and then decreased with the Mo level increasing. No significant difference in GSH concentration was found between
the different Mo treatments. Compared with the control, the GSSG concentration decreased significantly in the 0.01 mg l−1 Mo treatment. The activities of APX, MDHAR, DHAR and GR increased due to Mo application. But the activity of AAO decreased
with increasing Mo application rates. It is hypothesized that Mo may promote the redox process and regeneration of ascorbic
acid, and affect the ability of anti-oxidation in the Chinese cabbage.
Responsible Editor: Jian Feng Ma. 相似文献
205.
目的:探讨大鼠三叉神经节不同直径神经元ATP-激活电流的特征。方法:应用全细胞膜片钳技术进行实验。结果:①92.3%(60/65)的细胞对ATP敏感,有反应的细胞可记录到三种型式的ATP-激活电流:快速激活快速失活型(Fast type,F型)、快速激活缓慢失活型(Intermediate type,I型)和缓慢激活缓慢失活型(Slowtype,S型)。三种电流均具有浓度依赖性。②小直径的细胞多表现为F型特征,大直径的细胞多表现为S型特征,而中等大小的细胞多表现为I型特征。③动力学特征:三种类型的ATP激活电流上升相从10%到90%的时间:F型:(33.6±4.5)ms;Ⅰ型:(62.2±9.9)ms;S型:(302.1±62)ms。去敏感相从10%到90%的时间:F型:(399.4±58.2)ms;S型:>500ms。④I-V曲线:三种电流均表现为内向整流的特性,而且翻转电位均为0~5mV。⑤量-效关系:Ⅰ型的量-效曲线居中间,F型的下移,S型的上移,三种类型电流量-效曲线的EC50非常接近。结论:三种型式的ATP-激活电流可能是由不同亚单位组合的P2X受体各亚型所介导,这些亚型分布于不同大小的三叉神经节神经元,从而传导不同的信息。 相似文献
206.
Yousheng Rao Xu Shen Mengna Xia Chenglong Luo Qinghua Nie Dexiang Zhang Xiquan Zhang 《遗传、选种与进化》2007,39(5):569-582
An F2 chicken population was established from a crossbreeding between a Xinghua line and a White Recessive Rock line. A total of 502 F2 chickens in 17 full-sib families from six hatches was obtained, and phenotypic data of 488 individuals were available for analysis. A total of 46 SNP on GGA1 was initially selected based on the average physical distance using the dbSNP database of NCBI. After the polymorphism levels in all F0 individuals (26 individuals) and part of the F1 individuals (22 individuals) were verified, 30 informative SNP were potentially available to genotype all F2 individuals. The linkage map was constructed using Cri-Map. Interval mapping QTL analyses were carried out. QTL for body weight (BW) of 35 d and 42 d, 49 d and 70 d were identified on GGA1 at 351–353 cM and 360 cM, respectively. QTL for abdominal fat weight was on GGA1 at 205 cM, and for abdominal fat rate at 221 cM. Two novel QTL for fat thickness under skin and fat width were detected at 265 cM and 72 cM, respectively. 相似文献
207.
Gao Q Mezei G Nie Y Rao Y Choi CS Bechmann I Leranth C Toran-Allerand D Priest CA Roberts JL Gao XB Mobbs C Shulman GI Diano S Horvath TL 《Nature medicine》2007,13(1):89-94
Metabolic hormones, such as leptin, alter the input organization of hypothalamic circuits, resulting in increased pro-opiomelanocortin (POMC) tone, followed by decreased food intake and adiposity. The gonadal steroid estradiol can also reduce appetite and adiposity, and it influences synaptic plasticity. Here we report that estradiol (E2) triggers a robust increase in the number of excitatory inputs to POMC neurons in the arcuate nucleus of wild-type rats and mice. This rearrangement of synapses in the arcuate nucleus is leptin independent because it also occurred in leptin-deficient (ob/ob) and leptin receptor-deficient (db/db) mice, and was paralleled by decreased food intake and body weight gain as well as increased energy expenditure. However, estrogen-induced decrease in body weight was dependent on Stat3 activation in the brain. These observations support the notion that synaptic plasticity of arcuate nucleus feeding circuits is an inherent element in body weight regulation and offer alternative approaches to reducing adiposity under conditions of failed leptin receptor signaling. 相似文献
208.
Summary. Cervical cancer is one of the leading causes of female cancer death worldwide with about 500,000 deaths per year. Both mitomycin
C and cisplatin are alkylating agents, which bind and intercalate DNA, and thus used as anti-cancer drugs. In these studies,
we focused on investigating the apoptotic effects of intercalating agents on HPV-negative cervical cancer C-33A cells. Accordingly,
C-33A cells were treated with carboplatin, mitomycin C or cisplatin. Cell cycle analysis revealed that treatment with mitomycin
C and cisplatin but not with carboplatin resulted in apoptosis. Both mitomycin C and cisplatin induced apoptosis in C-33A
cells via caspase-8 and -3 processing in a Fas/FasL-dependent manner and also suppressed IL-18 expression, while they down-regulated
IκB expression and up-regulated p65 expression. These results suggest that both mitomycin C and cisplatin induce apoptosis,
not only via the caspase-8 and -3 dependent Fas/FasL pathway, but also via the regulation of NF-κB activity and IL-18 expression
in HPV-negative cervical cancer C-33A cells. 相似文献
209.
Anna CC Aguiar Ananda C Cunha Isabela Penna Ceravolo Regina A Correia Gon?alves Arildo JB Oliveira Antoniana Ursine Krettli 《Memórias do Instituto Oswaldo Cruz》2015,110(7):906-913
Several species of Aspidosperma plants are used to treat diseases in
the tropics, including Aspidosperma ramiflorum, which acts against
leishmaniasis, an activity that is experimentally confirmed. The species, known as
guatambu-yellow, yellow peroba,
coffee-peroba andmatiambu, grows in the Atlantic
Forest of Brazil in the South to the Southeast regions. Through a guided
biofractionation of A. ramiflorum extracts, the plant activity
against Plasmodium falciparum was evaluated in vitro for toxicity
towards human hepatoma G2 cells, normal monkey kidney cells and nonimmortalised human
monocytes isolated from peripheral blood. Six of the seven extracts tested were
active at low doses (half-maximal drug inhibitory concentration < 3.8 µg/mL); the
aqueous extract was inactive. Overall, the plant extracts and the purified compounds
displayed low toxicity in vitro. A nonsoluble extract fraction and one purified
alkaloid isositsirikine (compound 5) displayed high selectivity indexes (SI) (= 56
and 113, respectively), whereas compounds 2 and 3 were toxic (SI < 10). The
structure, activity and low toxicity of isositsirikine in vitro are described here
for the first time in A. ramiflorum, but only the neutral and
precipitate plant fractions were tested for activity, which caused up to 53%
parasitaemia inhibition of Plasmodium berghei in mice with
blood-induced malaria. This plant species is likely to be useful in the further
development of an antimalarial drug, but its pharmacological evaluation is still
required. 相似文献
210.
Xiao-Ru Yang Hu Li San-An Nie Jian-Qiang Su Bo-Sen Weng Gui-Bing Zhu Huai-Ying Yao Jack A. Gilbert Yong-Guan Zhu 《Applied and environmental microbiology》2015,81(3):938-947
The anaerobic oxidation of ammonium (anammox) process has been observed in diverse terrestrial ecosystems, while the contribution of anammox to N2 production in paddy soils is not well documented. In this study, the anammox activity and the abundance and diversity of anammox bacteria were investigated to assess the anammox potential of 12 typical paddy soils collected in southern China. Anammox bacteria related to “Candidatus Brocadia” and “Candidatus Kuenenia” and two novel unidentified clusters were detected, with “Candidatus Brocadia” comprising 50% of the anammox population. The prevalence of the anammox was confirmed by the quantitative PCR results based on hydrazine synthase (hzsB) genes, which showed that the abundance ranged from 1.16 × 104 to 9.65 × 104 copies per gram of dry weight. The anammox rates measured by the isotope-pairing technique ranged from 0.27 to 5.25 nmol N per gram of soil per hour in these paddy soils, which contributed 0.6 to 15% to soil N2 production. It is estimated that a total loss of 2.50 × 106 Mg N per year is linked to anammox in the paddy fields in southern China, which implied that ca. 10% of the applied ammonia fertilizers is lost via the anammox process. Anammox activity was significantly correlated with the abundance of hzsB genes, soil nitrate concentration, and C/N ratio. Additionally, ammonia concentration and pH were found to be significantly correlated with the anammox bacterial structure. 相似文献