Discovery of natural estrogen receptor modulators with structure-based virtual screening

Eleven compounds were identified as estrogen receptor modulators from an in-house natural product database (NPD) by structure-based virtual screening for ERα and ERβ. Among them, 3 compounds were confirmed as ER agonists and 8 compounds were confirmed as ER antagonists by yeast two-hybrid (Y2H) assay, with EC₅₀ values ranging from several micromolar to 100 micromolar. In this study, a novel series of cycloartane triterpenoids isolated from Schisandra glaucescens Diels was found to have ER antagonistic effect, the most potent antagonist of which exhibited activity with EC₅₀ value of 2.55 and 4.68 μM for ERα and ERβ, respectively. Moreover, the types of modulation and subtype selectivity were also investigated through molecular docking simulation.     

Natural products as a gold mine for selective matrix metalloproteinases inhibitors

Nineteen natural compounds with diverse structures are identified as potential MMPIs using structure-based virtual screening from 4000 natural products. Hydroxycinnamic acid or analogs of natural products are important for potent inhibitory and selectivity against MMPs, and the solvent effect in the S1' pocket can affect the hydrophobic interactions and hydrogen bonds between MMPIs and MMPS, making MMPIs exhibit certain selectivity for a specific MMP isoenzyme. Furthermore, compound 5 can reduce the expression of both MMP-2 and active-MMP-9, and suppress the migration of MDA-MB-231 tumor cell in a wound healing assay, which may be further developed as an anticancer agent.     

白僵菌超低容量油剂林间应用对生物多样性的影响

2001～2003年在福建省云霄县进行了白僵菌超低容量油剂林间防治马尾松毛虫后对生物多样性的影响研究(包括使用前后的物种丰富度S、个体数N、多样性指数H'、均匀度指数R和优势度指数D等),结果表明,未防治区和白僵菌油剂防治区的物种数分别为473种和392种,而化学防治区的物种数只有266种;白僵菌油剂防治区天敌和害虫个体数与未防治区的比例相近,分别为0．1049：1和0．1051：1．明显高于化学防治区(0．0558：1);化学防治和白僵菌油剂防治均降低了物种的丰富度和多样性。同时也增强了物种的优势度,但化学防治区与未防区的差异显著,白僵菌油剂防治区与未防区的差异不显著,尤其对天敌和非目标昆虫无显著影响。     

白僵菌超低容量油剂林间应用对生物多样性的影响

2001～2003年在福建省云霄县进行了白僵菌超低容量油剂林间防治马尾松毛虫后对生物多样性的影响研究(包括使用前后的物种丰富度S、个体数N、多样性指数H'、均匀度指数R和优势度指数D等).结果表明,未防治区和白僵菌油剂防治区的物种数分别为473种和392种,而化学防治区的物种数只有266种;白僵菌油剂防治区天敌和害虫个体数与未防治区的比例相近,分别为0.1049:1和0.1051:1,明显高于化学防治区(0.0558:1);化学防治和白僵菌油剂防治均降低了物种的丰富度和多样性,同时也增强了物种的优势度,但化学防治区与未防区的差异显著,白僵菌油剂防治区与未防区的差异不显著,尤其对天敌和非目标昆虫无显著影响.     

Lack of association between the G+2044A polymorphism of interleukin-13 gene and chronic obstructive pulmonary disease: a meta-analysis

Numerous studies have investigated association of interleukin-13 (IL-13) G+2044A polymorphism with COPD susceptibility; however, the results were inconsistent and inconclusive. To evaluate the association between the IL-13 G+2044A polymorphism and susceptibility to COPD, a meta-analysis of published case–control studies was performed. Based on PubMed and Chinese database, this research selected studies that examined the association of the IL-13 G+2044A polymorphism with COPD. A genetic model-free approach was used to assess whether the combined data showed this association. Then a subgroup analysis was also performed, with stratifications for race, study design, and sample size. Six studies (total 1,213 COPD patients and 801 control subjects) for the IL-13 G+2044A polymorphism with COPD were included in the meta-analysis (G- vs A-allele: OR 1.12, 95 % CI 0.96–1.32, P = 0.15; genotypes GG+GA vs genotype AA: OR 0.99, 95 % CI 0.49–2.00, P = 0.98; genotype GG vs genotypes GA+AA: OR 1.18, 95 % CI 0.97–1.44, P = 0.09; genotype GA vs genotypes GG+AA: OR 0.85, 95 % CI 0.70–1.04, P = 0.11). This meta-analysis demonstrates that the IL-13 G+2044A polymorphism does not confer susceptibility to COPD. More detailed data about individual and environment, larger sample sizes with unbiased genotyping methods and matched controls in different populations are required.     

Cross-sectional Seroprevalence and Genotype of Hepatitis E Virus in Humans and Swine in a High-density Pig-farming Area in Central China

Hepatitis E virus(HEV) infection is a common public health problem in developing countries. However, the current prevalence of HEV and the relationship of HEV genotype between swine and human within high-density pig-farming areas in central China are still inadequately understood. Here, cross-sectional serological and genotypic surveys of HEV among the 1232 general population, 273 workers occupationally exposed to swine, and 276 pigs in a high-density pig-breeding area, were undertaken by ELISA and nested RT-PCR methods. Anti-HEV IgG was detected in 26.22% of general population and 48.35% of occupational workers. The prevalence of swine serum HEV-Ag was 6.52%. The prevalence of anti-HEV IgG was significantly higher among the workers occupationally exposed to swine than among the general population. An increased HEV seropositivity risk among the general population was associated with either being a peasant or male and was very strongly associated with the increase of age. Among the occupationally exposed group, the prevalence of anti-HEV IgG antibodies increased with age and working years. Among the 30 HEV-IgM-positive people,the infection rates of clerks in the public, peasants, pork retailers, and pig farmers were higher than those of others. A phylogenetic analysis revealed that all the isolates belonged to subgenotype 4 d, and four people and four pigs shared97.04%–100% sequence homology. This study revealed a high HEV seroprevalence among the general population and workers occupationally exposed to swine in the Anlu City, and supports the notion that swine are a source of human HEV infection.     

Optical coherence tomography: fundamental principles, instrumental designs and biomedical applications

The advances made in the last two decades in interference technologies, optical instrumentation, catheter technology, optical detectors, speed of data acquisition and processing as well as light sources have facilitated the transformation of optical coherence tomography from an optical method used mainly in research laboratories into a valuable tool applied in various areas of medicine and health sciences. This review paper highlights the place occupied by optical coherence tomography in relation to other imaging methods that are used in medical and life science areas such as ophthalmology, cardiology, dentistry and gastrointestinal endoscopy. Together with the basic principles that lay behind the imaging method itself, this review provides a summary of the functional differences between time-domain, spectral-domain and full-field optical coherence tomography, a presentation of specific methods for processing the data acquired by these systems, an introduction to the noise sources that plague the detected signal and the progress made in optical coherence tomography catheter technology over the last decade.     

A Comparative Study on Polyphenolic Composition of Berries from the Tibetan Plateau by UPLC‐Q‐Orbitrap MS System

Five traditional medicinal food from the Tibetan plateau including Nitraria tangutorum Bobrov (NT), Hippophae rhamnoides L. (HR), Lycium ruthenicum Murray (LR), Lycium barbarum L. (LB) and Rubus corchorifolius L.f. (RC) are rich in phenolic compounds. However, the detailed studies about the phenolic compounds remain scarce. Therefore, we established a rapid method for the simultaneous identification and quantification of the phenolic compounds from berries via Ultra Performance Liquid Chromatography‐Quadruple‐Orbitrap MS system (UPLC‐Q‐Orbitrap MS). This method was verified from many aspects including detection limit, quantification limit, precision, repeatability, stability, average recovery rate and recovery range, and then was used to analyze the phenolic compounds in these five species of berries. Finally, a total of 21 phenolic compounds were directly identified by comparing the retention time and exact mass, of which 14 compounds were identified by us for the first time in berries from the Tibetan plateau, including one flavonoid aglycone (myricetin), 11 phenolic acids (gallic acid, protocatechuate, chlorogenic acid, vanillic acid, caffeic acid, syringic acid, p‐coumaric acid, ferulic acid, 2‐hydroxybenzeneacetic acid and ellagic acid), one flavanol (catechin) and one dihydrochalcone flavonoid (phloretin). Quantitative results showed that rutin, myricetin, quercetin and kaempferol were the main flavonoids. Moreover, a variety of phenolic acid compounds were also detected in most of the berries from the Tibetan plateau. Among these compounds, the contents of protocatechuate and chlorogenic acid were high, and high levels of catechin and phloretin were also detected in these plateau berries.