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排序方式: 共有21条查询结果,搜索用时 15 毫秒
1.
To investigate the expression and biological significance of Leptin, Leptin receptor, Vascular Endothelial Growth Factor (VEGF), and CD34 protein in colorectal carcinoma tissues. The expression of Leptin, Leptin receptor, VEGF, and CD34 was detected in 68 cases of colorectal carcinoma tissues, paired para-carcinoma tissues and normal colorectal tissues by Immunohistochemical SP Method. The results and related clinicopathological data were analyzed. The positive rate of Leptin, Leptin receptor, and VEGF was significantly higher in colorectal carcinoma tissues than that in paired para-carcinoma tissues and normal colorectal tissues. The expression of Leptin, Leptin receptor, and VEGF was correlated with grade of tumor differentiation, depth of bowel wall invasion, lymph node metastasis, Dukes stage, distant metastasis, and lympho/vascular tumor embolization. Microvessel density (MVD) value in colorectal carcinoma was significantly higher than that in para-carcinoma tissues and normal colorectal tissues, and the density in para-carcinoma tissues was higher than that in normal colorectal tissues. The expression of Leptin, Leptin receptor, VEGF, and MVD value in colorectal carcinoma was positively correlated. In conclusion, microvessel density value is an important index of the growth, invasion, and metastasis of colorectal carcinoma. The binding of Leptin and Leptin receptor promotes the proliferation of colorectal carcinoma cells. The synergy between Leptin and VEGF accelerates the angiogenesis in colorectal carcinoma and accelerates the invasion and metastasis of the tumor cells.  相似文献   
2.
The luxR homolog aviR in Agrobacterium vitis strain F2/5 was recently shown to be associated with induction of a hypersensitive response (HR) on tobacco and necrosis on grape plants, indicating that the responses are regulated by quorum sensing. We now report a second luxR homolog, avhR, whose disruption (mutant M1320) results in HR-negative and reduced grape necrosis phenotypes. The deduced AvhR protein has characteristic autoinducer binding and DNA binding domains and is unique among reported functional LuxR homologs in having substitutions at highly conserved Asp70, Trp57, and Trp85 residues, which are predicted to play important roles in autoinducer binding in TraR. M1320 was fully complemented with cloned avhR. The same array of N-acylhomoserine lactones (AHL) from F2/5, M1320, and complemented M1320 were observed; however, the signal strength from extracts of 6-day-old M1320 cultures was stronger than that of F2/5. Cultures of F2/5 amended with AHL extracts from overnight and 6-day cultures of F2/5 and M1320 were not affected in ability to cause HR or necrosis. A region of about 14 kb flanking avhR was sequenced and compared with homologous regions of A. tumefaciens C58 and Sinorhizobium meliloti Rm1021 genomes. Gene order and homology are conserved between the species. A site-directed mutation in a putative gene that resides downstream of avhR and that has homology to genes belonging to the ATP-binding cassette transporter family did not affect HR or necrosis phenotypes. It was determined that avhR and aviR are expressed independently and that neither regulates the expression of a clpA homolog in F2/5.  相似文献   
3.
Two new members of the polyketide synthase (PKS) gene family (RiPKS4 and RiPKS5) were cloned from raspberry fruits (Rubus idaeus L., cv Royalty) and expressed in Escherichia coli. Characterization of the recombinant enzyme products indicated that RiPKS4 is a bifunctional polyketide synthase producing both 4-hydroxybenzalacetone and naringenin chalcone. The recombinant RiPKS4 protein, like the native protein from raspberry fruits [W. Borejsza-Wysocki, G. Hrazdina, Plant Physiol. 1996;110: 791-799] accepted p-coumaryl-CoA and ferulyl-CoA as starter substrates and catalyzed the formation of both naringenin chalcone, 4-hydroxy-benzalacetone and 3-methoxy-4-hydroxy-benzalacetone. Although activity of RiPKS4 was higher with ferulyl-CoA than with p-coumaryl-CoA, the corresponding product, 3-methoxy-4-hydroxy phenylbutanone could not be detected in raspberries to date. Sequence analysis of the genes and proteins suggested that this feature of RiPKS4 was created by variation in the C-terminus due to DNA recombination at the 3′ region of its coding sequence. RiPKS5 is a typical chalcone synthase (CHS) that uses p-coumaryl-CoA only as starter substrate and produces naringenin chalcone exclusively as the reaction product.  相似文献   
4.
Summary Thidiazuron (TDZ) is a substituted phenylurea which has been shown to be an efficacious regulator of in vitro morphogenesis of many dicot plant species. However, information regarding the effect of TDZ on in vitro regeneration of monocot species is limited. We investigated the effects of TDZ on in vitro regeneration of barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) and found that it promoted shoot regeneration from callus in these two important cereal species. Plant regeneration from calluses derived from immature embryo culture of barley and wheat was observed in regeneration media with a wide range of TDZ concentrations (0.045–45 μM). Shoot regeneration from barley calluses was the highest (38.3% for cv. Golden Promise) at 4.5 μM (1 mg l−1) TDZ, while the optimal TDZ level for wheat regeneration seemed to be 0.9 μM (0.2 mg l−1) (87% for cv. Bob White and 49.4% for cv. Hi Line). Roots developed normally when the regenerated wheat and barley shoots from TDZ-containing media were transferred to the rooting medium. Comparison with other plant growth regulators commonly used in wheat and barley regeneration media suggested that TDZ was among the best for in vitro regeneration of wheat and barley. Both authors contributed equally  相似文献   
5.
Onion seeds treated with leachates of composts prepared from alfalfa and sunflower stalks, at the dosages of 10% and 20% respectively, were inoculated with Aspergillus niger van Tieghem, causal agent of onion black mold disease. The ability of the leachates to induce the production of antifungal compounds and to control black mold were tested at seedling and set stages. Leachates from both composts were able to reduce disease incidence in sets, but not disease severity in onion seedlings. Extracts from treated seedlings and sets were fractionated by thin layer chromatography for their content of antifungal compounds. There were no significant differences between the fractions of alfalfa and sunflower compost leachates in the inhibition of the mycelium growth of A. niger, with the exception of one fraction. The presence of fluorescent pseudomonads and Pantoae agglomerans [synonym: Erwinia herbicola (Löhnis)] bacteria was determined in both leachates. The population of P. agglomerans was higher in the sunflower compost leachate compared to the alfalfa leachate. The tested strains of both bacteria were able to inhibit mycelium growth of the fungal pathogen in agar tests. This study suggests the possible role of beneficial bacteria in the induction of antifungal compounds in onion against A. niger during seedling and set stages.  相似文献   
6.
应用生物信息学方法,构建结肠腺癌(COAD)丝氨酸蛋白酶抑制剂(SERPIN)家族相关基因预后模型。从TCGA数据库和GEO数据库下载结肠腺癌(COAD)转录组和临床数据,根据数据中SERPINs家族基因的表达量对COAD患者进行一致性聚类分析;将数据随机均分为训练集(Train)组和验证集(Test)组,基于两个亚型的差异基因,利用Train组进行COX回归和Lasso回归构建预后模型,根据模型风险评分中位值将样本分为高、低风险两组,绘制高低风险组患者生存曲线;通过ROC曲线评价模型预测能力;利用Test组数据验证模型;构建列线图,评估患者生存率模型预测值与实际值的一致性;并利用利用ESTIMATE算法和CIBERSORT算法评估风险评分和肿瘤微环境(TME)以及免疫浸润的相关性。通过34个SERPIN基因确定了两个亚型,基于2个亚型筛选出了436个预后相关分型差异基因,通过Lasso回归确定出了11个预后相关基因参与风险模型的构建,根据模型评分区分的高低风险组具有明显的生存差异,列线图可以准确预测1、3和5年生存率。肿瘤微环境分析和免疫浸润分析显示高风险评分组患者免疫活性差。SERPIN家族相关基因构建的风险评分模型能够预测COAD的预后,有利于进一步指导临床对COAD的诊治,提高患者生存率。  相似文献   
7.
以黑果枸杞为材料,利用RT PCR和RACE技术克隆了花青素合成相关基因LrTTG1(GenBank登录号为MH633481)。序列分析表明,LrTTG1基因cDNA全长1 453 bp,包含1 029 bp开放阅读框,编码342个氨基酸,含有5个WD40重复基序。同源比对结果表明,LrTTG1与茄子SmTTG1的氨基酸序列相似性较高,达到83.73%。qRT PCR分析显示,LrTTG1基因在茎、叶、花、青果、紫果和黑果中均有表达,且在青果中的表达水平(最高)约为黑果(最低)的4倍;紫外胁迫下LrTTG1基因的表达随胁迫时间的延长呈先降低后升高的变化趋势。花青素含量分析表明,黑果的花青素含量最高(11.3 mg/g),分别约为紫果( 1.2 mg/g)和青果(0.53 mg/g)含量的9.4倍和21.3倍。研究表明,随着黑果枸杞果实的发育,LrTTG1基因的表达量呈现下降趋势,而花青素的含量则呈上升趋势,两者呈负相关关系;推测LrTTG1基因在黑果枸杞花青素合成中可能具有重要的调节作用。  相似文献   
8.
Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) and Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) are egg parasitoids of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). We observed and recorded the walking patterns of T. chilonis and T. bactrae females on leaves of Raphanus sativus L., Brassica juncea (L.) Czern. et Coss., Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee, and Brassica oleracea L. Our analysis indicated that Trichogramma females spent more time and moved more slowly on R. sativus leaf surface, compared with the other vegetable leaf surfaces. In addition, Trichogramma females were more likely to walk in straight line on B. oleracea leaf surfaces than R. sativus, B. juncea, and B. campestris leaf surface. Compared to T. bactrae females, T. chilonis females spent significantly less time on the leaf surface, and the walking path of T. chilonis was less affected by leaf surface characters (e.g., trichomes, wrinkle, and waxes). During the period of residence on the leaf surface, parasitoid females spent more than 87.8% of their time moving. This study demonstrates that vegetable leaf surface can influence Trichogramma's walking pattern while they are foraging for hosts.  相似文献   
9.
Wang D  Ma Y  Li Z  Kang K  Sun X  Pan S  Wang J  Pan H  Liu L  Liang D  Jiang H 《Autophagy》2012,8(6):954-962
Hydrogen sulphide (H 2S) exerts a protective effect in hepatic ischemia-reperfusion (I/R) injury. However, the exact mechanism of H 2S action remains largely unknown. This study was designed to investigate the role of the PtdIns3K-AKT1 pathways and autophagy in the protective effect of H 2S against hepatic I/R injury. Primary cultured mouse hepatocytes and livers with or without NaHS (a donor of H 2S) preconditioning were exposed to anoxia/reoxygenation (A/R) and I/R, respectively. In certain groups, they were also pretreated with LY294002 (AKT1-specific inhibitor), 3-methyladenine (3MA, autophagy inhibitor) or rapamycin (autophagy enhancer), alone or simultaneously. Cell viability, expression of P-AKT1, T-AKT1, LC3 and BECN1 were examined. The severity of liver injury was measured by the levels of serum aminotransferase and inflammatory cytokine, apoptosis and histological examination. GFP-LC3 redistribution and transmission electron microscopy were used to test the activity of autophagy. H 2S preconditioning activated PtdIns3K-AKT1 signaling in hepatocytes. LY294002 could abolish the AKT1 activation and attenuate the protective effect of H 2S on hepatocytes A/R and hepatic I/R injuries. H 2S suppressed hepatic autophagy in vitro and in vivo. Further reducing autophagy by 3MA also diminished the protective effect of H 2S, while rapamycin could reverse the autophagy inhibitory effect and enhance the protective effect of H 2S against hepatocytes A/R and hepatic I/R injuries, consequently. Taken together, H 2S protects against hepatocytic A/R and hepatic I/R injuries, at least in part, through AKT1 activation but not autophagy. An autophagy agonist could be applied to potentiate this hepatoprotective effect by reversing the autophagy inhibition of H 2S.  相似文献   
10.

Background

Numerous clinical trials have demonstrated that elderly patients with colorectal cancer (CRC) can benefit from chemotherapy, yet compliance in real-world practice is low. The purpose of this study is to investigate the efficacy, compliance and reasons for refusal of postoperative chemotherapy for elderly patients with CRC and to provide corresponding strategies.

Patients and methods

The clinico-pathological and biochemical data of the chemotherapy group and chemo-refusing group were compared among 386 elderly patients (>70 years old) with CRC who underwent surgery. 226 patients received chemotherapy and 160 patients refused. Follow-up of the subjective reasons for refusal was investigated using the elderly caner patients'' chemo-refusal reason questionnaire (ECPCRRQ) prepared by the authors and a group of psychologists. The questionnaire is administrated by telephone. A predictive model for 5-year disease-free survival (DFS) and 5-year overall survival (OS) was constructed by using Kaplan-Meier analysis, logistic and Cox regression.

Results

Among stage III patients, receiving chemotherapy was associated with a significantly higher OS (68%) compared to those who refused (OS50%) (HR: 2.05, 95%CI: 1.12–3.77, P = 0.02). The Chemo-refusal group had more female and elderly patients, significantly higher rate of severe complications, and lower body mass index (BMI). Follow-up phone questionnaire analysis showed the doctors’ uncertainty of chemotherapy benefit, economic difficulties, uncomfortable feeling, superstition of Traditional Chinese Medicine, concealing information and lack of social support were the main factors for elderly CRC patients to decline chemotherapy.

Conclusion

The receipt of post-operative chemotherapy in elderly patients with resected stage III CRC was associated with a more favorable survival. The low compliance rate (160/386) of postoperative chemotherapy was influenced by various subjective and objective factors.  相似文献   
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