Antioxidant Activity and α-Glucosidase Inhibitory Activities of the Polycondensate of Catechin with Glyoxylic Acid

In order to investigate polymeric flavonoids, the polycondensate of catechin with glyoxylic acid (PCG) was prepared and its chemically antioxidant, cellular antioxidant (CAA) and α-glucosidase inhibitory activities were evaluated. The DPPH and ABTS radical scavenging activities and antiproliferative effect of PCG were lower than those of catechin, while PCG had higher CAA activity than catechin. In addition, PCG had very high α-glucosidase inhibitory activities (IC₅₀ value, 2.59 μg/mL) in comparison to catechin (IC₅₀ value, 239.27 μg/mL). Inhibition kinetics suggested that both PCG and catechin demonstrated a mixture of noncompetitive and anticompetitive inhibition. The enhanced CAA and α-glucosidase inhibitor activities of PCG could be due to catechin polymerization enhancing the binding capacity to the cellular membrane and enzymes.     

The p53 isoforms are differentially modified by Mdm2

The discovery that the single p53 gene encodes several different p53 protein isoforms has initiated a flurry of research into the function and regulation of these novel p53 proteins. Full-length p53 protein level is primarily regulated by the E3-ligase Mdm2, which promotes p53 ubiquitination and degradation. Here, we report that all of the novel p53 isoforms are ubiquitinated and degraded to varying degrees in an Mdm2-dependent and -independent manner, and that high-risk human papillomavirus can degrade some but not all of the novel isoforms, demonstrating that full-length p53 and the p53 isoforms are differentially regulated. In addition, we provide the first evidence that Mdm2 promotes the NEDDylation of p53β. Altogether, our data indicates that Mdm2 can distinguish between the p53 isoforms and modify them differently.     

野生樱桃李扦插繁殖研究初报

以野生樱桃李的新梢为试材,采用不同的扦插基质、不同浓度的吲哚丁酸(IBA)、萘乙酸(NAA)和生根粉(ABR)对野生樱桃李插条进行扦插生根试验.试验结果表明,野生樱桃李在蛭石与河沙中的生根效果好于锯末中的生根,蛭石与河沙中插条的生根率接近,生根率分别达到了40.0%、39.6%,因此都可作为野生樱桃李扦插的适宜基质.适宜浓度NAA、IBA可以促进野生樱桃李的生根,浓度过低,达不到促进效果,浓度过高,则可能抑制了插条的生根,相比而言,效果NAA较好,其适宜处理浓度为200 mg/L.但各种激素处理后,无论生根率高低,对根的生长具有促进作用.     

Efficacy of p-Toluoyl chloride phenylhydrazone against gastrointestinal helminths in ovines.

A new anthelmintic candidate, p-toluoyl chloride phenlylhydrazone, was administered to lambs in a paste formulation. The efficacy of this drug was determined at dose rates of 20, 30, 40, and 50 mg of active ingredient per kilogram of body weight. Helminths expelled by these dosages included Haemonchus contortus, Ostertagia circumcicta, Trichostrongylus colubriformis, T. axei, Nematodirus filicollis, Cooperia curticei, Strongyloides papillosus, Oesophagostomum columbianum, Bunostomum trigoncephalum, Chabertia ovina, Moniezia expansa, and M. benedeni.     

Functional analysis of a miRNA‐like small RNA derived from Bombyx mori cytoplasmic polyhedrosis virus

Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) is a major pathogen of the economic insect silkworm, Bombyx mori. Virus‐encoded microRNAs (miRNAs) have been proven to play important roles in host–pathogen interactions. In this study we identified a BmCPV‐derived miRNA‐like 21 nt small RNA, BmCPV‐miR‐1, from the small RNA deep sequencing of BmCPV‐infected silkworm larvae by stem‐loop quantitative real‐time PCR (qPCR) and investigated its functions with qPCR and lentiviral expression systems. Bombyx mori inhibitor of apoptosis protein (BmIAP) gene was predicted by both target prediction software miRanda and Targetscan to be one of its target genes with a binding site for BmCPV‐miR‐1 at the 5′ untranslated region. It was found that the expression of BmCPV‐miR‐1 and its target gene BmIAP were both up‐regulated in BmCPV‐infected larvae. At the same time, it was confirmed that BmCPV‐miR‐1 could up‐regulate the expression of BmIAP gene in HEK293T cells with lentiviral expression systems and in BmN cells by transfecting mimics. Furthermore, BmCPV‐miR‐1 mimics could up‐regulate the expression level of BmIAP gene in midgut and fat body in the silkworm. In the midgut of BmCPV‐infected larvae, BmCPV‐miR‐1 mimics could be further up‐regulated and inhibitors could lower the virus‐mediated expression of BmIAP gene. With the viral genomic RNA segments S1 and S10 as indicators, BmCPV‐miR‐1 mimics could up‐regulate and inhibitors down‐regulate their replication in the infected silkworm. These results implied that BmCPV‐miR‐1 could inhibit cell apoptosis in the infected silkworm through up‐regulating BmIAP expression, providing the virus with a better cell circumstance for its replication.     

MALE PEACH APHID ATTRACTION IN THE FIELD BY SEX PHEROMONES1)

Abstract Field trials by sex pheromone of aphid to trap peach aphids Myzus persicae have been carried out in 1995 and in 1996. Suitable time and the effect of ratio of two components nepetalactone and nepetalactol to apply the lure have been observed.     

Modulation of human mammary cell sensitivity to paclitaxel by new quinoline sulfonamides.

Sulfonamide derivatives of chloroquine and primaquine were synthesised and evaluated against both paclitaxel-sensitive and paclitaxel-resistant mammarian cancer cell lines. All derivatives exhibited at least 96% MDR reversal activity when co-administered with paclitaxel at 5 microM. The best compound, a chloroquine derivative, exhibited 99% MDR reversal activity when co-administered with paclitaxel at 1 microM. Molecular modelling studies reveal that these derivatives share a common pharmacophore with taxane MDR reversal agents.     

Automatic non-proliferative diabetic retinopathy screening system based on color fundus image

Background

Non-proliferative diabetic retinopathy is the early stage of diabetic retinopathy. Automatic detection of non-proliferative diabetic retinopathy is significant for clinical diagnosis, early screening and course progression of patients.

Methods

This paper introduces the design and implementation of an automatic system for screening non-proliferative diabetic retinopathy based on color fundus images. Firstly, the fundus structures, including blood vessels, optic disc and macula, are extracted and located, respectively. In particular, a new optic disc localization method using parabolic fitting is proposed based on the physiological structure characteristics of optic disc and blood vessels. Then, early lesions, such as microaneurysms, hemorrhages and hard exudates, are detected based on their respective characteristics. An equivalent optical model simulating human eyes is designed based on the anatomical structure of retina. Main structures and early lesions are reconstructed in the 3D space for better visualization. Finally, the severity of each image is evaluated based on the international criteria of diabetic retinopathy.

Results

The system has been tested on public databases and images from hospitals. Experimental results demonstrate that the proposed system achieves high accuracy for main structures and early lesions detection. The results of severity classification for non-proliferative diabetic retinopathy are also accurate and suitable.

Conclusions

Our system can assist ophthalmologists for clinical diagnosis, automatic screening and course progression of patients.

     

长期施肥对双季稻田甲烷排放和关键功能微生物的影响

研究不同施肥措施对双季稻田甲烷(CH_4)排放特征的影响及其微生物学机理,对合理利用及评价不同施肥模式对水稻生长的影响具有重要意义。以长期施肥定位试验田为平台,采用静态箱-气相色谱法对施用化肥(MF:mineral fertilizer alone)、秸秆还田配施化肥(RF:rice residues plus mineral fertilizer)、30%有机肥配施70%化肥(LOM:30%organic matter plus 70%mineral fertilizer)、60%有机肥配施40%化肥(HOM:60%organic matter plus 40%mineral fertilizer)和无肥(CK:without fertilizer)条件下双季稻田CH_4排放及其微生物学机理进行了分析。结果表明,早稻和晚稻生长期,不同施肥处理稻田CH_4排放通量均显著高于CK,表现为HOMLOMRFMFCK。各处理间CH_4总排放量差异达显著水平,其大小顺序与排放通量趋势一致,以HOM处理为最高,比CK处理增加105.56%,其次是LOM和RF处理,分别比CK处理增加72.97%和54.17%。关键功能土壤微生物测定结果表明,早稻和晚稻各个主要生育时期,各处理稻田土壤产甲烷古菌的数量变化范围为(3.18—81.07)×10~3cfu/g,土壤甲烷氧化细菌的数量变化范围为(24.82—379.72)×10~3cfu/g。稻田土壤产甲烷古菌和甲烷氧化细菌数量大小顺序为HOMLOMRFMFCK,各施肥处理均显著高于CK;HOM、LOM、RF处理显著高于MF、CK处理。双季稻田CH_4排放与稻田土壤产甲烷古菌、甲烷氧化细菌数量变化关系密切。采用有机无机肥配施促进了双季稻田生态系统CH_4的排放和关键功能微生物的数量。