Screening of Epstein-Barr Virus Early Antigen Expression Inducers from Chinese Medicinal Herbs and Plants

Ether extrilcls of 1693 Chinesc medicinal herbs and plilnts from 268 families werestudied for the induction of Epstcin-Barr viral (EBV ) early antigcn (EA ) expression in theRaji cell line. Fifty-two from 18 families were found to have inducing activity. Twenty-fiveand seven of them were from Euphorbiaccae and Thymclaeaceae, respectively. Some ofthem, such as Croton tiglium, Euphorbia kansui, Daphnc genkwa, Wikstrocmia chamacdaphen, Wikstroemia indica, Prunus mandshurica Koehne and Achyranthes bidentata arecommonly used drugs. The significance of these herbs in the activation of EBV in vivo andtheir relation to the development of nasopharyngeal carcinoma were discussed.

Express Screening of Biological Objects Using Multisensor Stripping Voltamperometry with Pattern Recognition

Express diagnostics of biological objects is necessary for operational preliminary assessment of the condition of the patient. A method of recognition of differences between the norm and pathology is based on analysis of multidimensional patterns of the voltamperogram electrochemical test systems in Electronic formats “language”, “electronic nose”. The basis of such systems is the use of a set (matrix) sensor with completely different characteristics. A. N. Frumkin Institute of Physical Chemistry and Electrochemistry RAS (IPCE) developed a method for multidimensional stripping voltammetry, which allowed you to provide information on biological matter being investigated not as a number, as a response to a single dimension, and in the form of N-dimensional image. Formats are implemented in the process of electrochemical studies of liquid or gaseous phase. Evaluating the closeness of the resulting image object under test with known samples is collected in a database. Examples of express diagnostics of glaucoma are with accordance of the results of the electrochemical research of blood serum.

Expression, purification and activity assay of recombinant human thymidylate synthase

Thymidylate synthase （TS, E.C.2.1.1.45） catalyzes a critical reaction in the only pathway of de novo synthesis of thymidylate （dTMP） in human cells, and is an important target of chemotherapy. To evaluate the inhibitory activities of novel compounds to TS, a convenient method of activity assay using 6x His-tagged recombinant human TS （rhTS） was established and 49 novel synthetic folate analogues were screened to discover potential TS inhibitors. During the process, 4 novel compounds were found to effectively inhibit TS, while the IC 50 of a positive control raltitrexed was 3.4 μM in this assay.

A small scale expression screen identifies tissue specific markers in the Dugesia japonica strain Pek-1

Freshwater planaria has tremendous capacity to reform the missing part of the body and therefore is considered as one of the most important model organism for regeneration study. At present, Schmidtea mediterranea and Dugesia japonica are the two major species utilized for laboratory manipulations. Dugesia japonica flatworms are widely distributed in the Far East including Cherry Valley region in the north-west area of Beijing, China. We reported here the establishment of an asexual Dugesiajaponica strain Pek-1, as a suitable system for regeneration study. Using morphological, karyotypical as well as phylogenetic analyses, we confirmed that these flatworms indeed belonged to Dugesia japonica. We went on to show that the commonly used in situ probes and immunohistochemistry reagents and protocols were applicable to the Pek-1 strain. Using this strain, we carried out small scale analysis on EST, RNAi and gene expression. We identified 193 unique EST sequences and 65 of them had not been reported in planarian. By RNAi analysis, we showed that 48 genes, when down-regulated individually, had no effect on regeneration. Furthermore, we identified 3 groups of tissue specific expressing genes that were useful for cell lineage analysis. We concluded that the Dugesiajaponica Pek-1 strain could be another suitable animal model to regeneration research.

A screening assay for thyroid hormone signaling disruption based on thyroid hormone-response gene expression analysis in the frog Pelophylax nigromaculatus

Amphibian metamorphosis provides a wonderful model to study the thyroid hormone（TH）signaling disrupting activity of environmental chemicals, with Xenopus laevis as the most commonly used species. This study aimed to establish a rapid and sensitive screening assay based on TH-response gene expression analysis using Pelophylax nigromaculatus, a native frog species distributed widely in East Asia, especially in China. To achieve this, five candidate TH-response genes that were sensitive to T3 induction were chosen as molecular markers, and T3 induction was determined as 0.2 nmol/L T3 exposure for 48 hr. The developed assay can detect the agonistic activity of T3 with a lowest observed effective concentration of 0.001 nmol/L and EC50 at around 0.118–1.229 nmol/L, exhibiting comparable or higher sensitivity than previously reported assays. We further validated the efficiency of the developed assay by detecting the TH signaling disrupting activity of tetrabromobisphenol A（TBBPA）, a known TH signaling disruptor. In accordance with previous reports, we found a weak TH agonistic activity for TBBPA in the absence of T3,whereas a TH antagonistic activity was found for TBBPA at higher concentrations in the presence of T3, showing that the P. nigromaculatus assay is effective for detecting TH signaling disrupting activity. Importantly, we observed non-monotonic dose-dependent disrupting activity of TBBPA in the presence of T3, which is difficult to detect with in vitro reporter gene assays. Overall, the developed P. nigromaculatus assay can be used to screen TH signaling disrupting activity of environmental chemicals with high sensitivity.