Retraction notice to "Betulinic acid downregulates expression of oxidative stress-induced lipoprotein lipase via PKC/ERK/c-Fos pathways in RAW264.7 macrophages" [Biochimie 119C (2015) 192-203].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Concerns raised by Dr. Sander Kersten in PubPeer pointed out that Figs. 6.1B and 6.2B of this paper were different figures but the legends and Western blots were identical; the quantification was also seen to be different between the two figures. Shortly afterwards, the authors asked to publish a corrigendum for part B of Fig. 6.1, including images of western blots and associated bar plots. Subsequently, the journal conducted an investigation and found evidence that there had been improper manipulation and duplication of images in Fig. 2 E, 6.2 B, 5 A and and 6.2 D, as shown by the reuse of several western blot bands with approximately 180° rotation in each case. After raising the complaint with the authors, the corresponding author agreed that the paper should be retracted. The authors apologise to the readers of the journal.

[Mechanisms and application of triptolide against breast cancer].

Overtaking lung cancer,breast cancer is now the most commonly diagnosed cancer seriously threatening people's health and life. As the main effective component of Tripterygium wilfordii,triptolide( TP) has attracted increasing attention due to its multitarget and multi-pathway anti-tumor activity. Recent studies have revealed that breast cancer-sensitive TP enables the inactivation of breast cancer cells by inducing tumor cell apoptosis and autophagy,interfering in tumor cell metastasis,resisting drug resistance,arresting tumor cell cycle,and influencing tumor microenvironment. It has been recognized as a promising clinical antitumor agent by virtue of its widely accepted therapeutic efficacy. This paper reviewed the anti-breast cancer action and its molecular mechanisms of TP on the basis of the relevant literature in the past ten years,and proposed application strategies in view of the inadequacy of TP to provide a reference for further research on the application of TP in the treatment of breast cancer.

[Prescription compatibility connotation and action mechanism of Siwu Decoction in treating primary dysmenorrhea].

The aim of this paper was to study the prescription compatibility connotation in the treatment of primary dysmenorrhea(PD) and verify the mechanism as predicted by network pharmacology of Siwu Decoction(SWD). Mice PD model was constructed by using estradiol benzoate-oxytocin. PD mice were randomly divided into 8 groups, namely normal group, model group, positive group, complete formula group, Rehmanniae Radix Praeparata-free group, Paeoniae Radix Alba-free group, volatile oil-free group, Chuan-xiong Rhizoma and Angelicae Sinensis Radix-free group. Latent time, writhing times, inhibition rate, prostaglandin F_2_α(PGF_2_α) and prostaglandin E_2(PGE_2) levels in serum, endothelin-1, Ca~(2+), expression levels of prostaglandin synthase 2 G/H(PTGS2), estrogen receptor(ESR1), glucocorticoid receptor gene(NR3 C1) mRNA and protein expression levels in the uterus homogenate and pathological changes of uterine tissue were index to explore the prescription compatibility connotation and verify the mechanism of SWD in the treatment of PD. Compared with the extraction liquid of the whole recipe, the effect of Rehmanniae Radix Praeparata-free group and Paeoniae Radix Alba-free group with volatile oil were slightly lower, the effect of essential oil-free group was significantly lower, and the effect of Chuanxiong Rhizoma and Angelicae Sinensis Radix-free group was worse than that of the whole recipe. The relative expression levels of PTGS2 protein and mRNA were significantly reduced by the SWD. The relative expressions of protein and mRNA of ESR1, NR3 C1 were significantly increased. SWD treats PD by regulating the expression of key proteins PTGS2, ESR1 and NR3 C1.Its main medicinal herbs were Angelicae Sinensis Radix and Chuanxiong Rhizoma. Active components were mainly in volatile oil, but Paeo-niae Radix Alba and Rehmanniae Radix Praeparata also had some contributions.

[Pharmacodynamics of Siwu Decoction on blood supply based on factor analysis].

To evaluate the pharmacodynamic effect of Siwu Decoction in treating blood deficiency in mice under multidimensional pharmacodynamic indexes by factor analysis. The mouse blood deficiency model was established with cyclophosphamide combined with acetophenone; and mouse organ index,white blood cells,red blood cell,hemoglobin,platelet counts in whole blood,serum granulocyte-macrophage colony-stimulating factor,macrophagecolony-stimulating factor,promotion erythropoietin,interleukin-3 and interleukin-6 were used as indicators to characterize the blood-enriching effect of Siwu Decoction; the pharmacodynamic effect of Siwu Decoction on blood deficiency model was evaluated comprehensively by factor analysis. Four common factors were extracted from 14 pharmacodynamics indexes through the factor analysis,namely blood phase factor,viscera index,hematopoietic regulatory factor 1-spleen index and hematopoietic regulatory factor 2-viscera index. The cumulative contribution rate of variance reached 86. 581%. The comprehensive score of factor analysis showed that Siwu Decoction had the best effect on blood replenishment,and it is significant compared with the model group( P<0. 01). The effect of alcohol precipitation of Siwu Decoction was slightly decreased. The study showed that Siwu Decoction has the best blood-enriching effect,followed by water decoction and traditional decoction. Alcohol precipitation had the worst effect. Factor analysis can be used for the comprehensive evaluation of blood deficiency mice model,and is a suitable evaluation method for animal model for multi-dimensional multistage complex data analysis. It provides a new model to evaluate the efficacy of multidimensional data in the future.

[Research progress on triptolide functionalized nanoparticulate drug delivery systems for tumor treatment].

Nowadays,the advantages of traditional Chinese medicine(TCM) for treatment of tumors are increasingly prominent.Triptolide shows wide-spectrum and highly effective anti-tumor activity. Moreover,nano-carrier-based triptolide drug delivery system is more powerful in improving water solubility and pharmacokinetic behavior of the drug,but it is easy to cause toxic and side effects that should not be neglected on human body. Because of tumor vascular heterogeneity and PEGylation dilemma,nanoparticulate drug delivery systems need to overcome multiple physiological and pathological barriers from drug administration to functioning. It is difficult for traditional triptolide nanoparticulate drug delivery systems to achieve active accumulation of nano-drug in tumor tissues and specific drug release in tumor target site solely relying on enhanced permeability and retention effect of solid tumor,limiting their application and clinical transformation in treatment of tumors. Based on the traditional nano-preparation system,the new functionalized nano-drug delivery system further enhances the nano-drug enrichment,penetration and controlled release at the tumor sites,which is of great significance in improving bioavailability,anti-tumor efficacy and reducing the side effects of drugs. In this paper,we summarized and analyzed the researches on new triptolide functionalized nano-drug delivery system from four perspectives,including tumor active targeting,tumor microenvironment response,polymer-drug conjugates,and multidrug co-delivery for tumor treatment,expecting to provide ideas for in-depth research and clinical application of triptolide and some other active anti-tumor TCM ingredients.

[Research progress on anti-tumor effects and mechanisms of triptolide and its combined application].

Tumors are major chronic diseases and seriously threaten human health all over the world. How to effectively control and cure tumors is one of the most pivotal problems in the medical field. At present,surgery,radiotherapy and chemotherapy are still the main treatment methods. However,the side effects of radiotherapy and chemotherapy cannot be underestimated. Therefore,it is of great practical significance to find new anti-cancer drugs with low toxicity,high efficiency and targeting to cancer cells. With the increasing incidence of tumor,the anti-tumor effect of traditional Chinese medicine has increasingly become a research hotspot. Triptolide,which is a natural diterpenoid active ingredient derived from of Tripterygium wilfordii,as one of the highly active components,has anti-inflammatory,immunosuppressive,anti-tumor and other multiple effects. A large number of studies have confirmed that it has good anti-tumor activity against various tumors in vivo and in vitro. It can play an anti-tumor role by inhibiting the proliferation of cancer cells,inducing apoptosis of cancer cells,inducing autophagy of cancer cells,blocking the cell cycle,inhibiting the migration,invasion and metastasis of cancer cells,reversing multidrug resistance,mediating tumor immunity and inhibiting angiogenesis. On the basis of literatures,this paper reviews the anti-tumor effect and mechanism of triptolide,and analyzes the current situation of triptolide combined with other chemotherapy drugs,in order to promote deep research and better clinical application about triptolide.

[Network pharmacology-based study on mechanism of Siwu Decoction in treatment of primary dysmenorrhea].

This paper aimed to predict and explore the mechanism of multiple components, targets and pathways of Siwu decoction for treatment of primary dysmenorrhea, and to establish a network pharmacological model of "compound-target-pathway-disease". According to the active ingredients in Siwu Decoction, Swiss Target Prediction server was used to predict the active component targets based on the reverse pharmacodynamic group matching method, and the primary dysmenorrhea targets approved by FDA were selected by database including DrugBank, OMIM and TTD. According to the enrichment analysis of the target pathways by using KEGG, the Cytoscape software was used to construct the network of "compound-target-pathway-disease" of Siwu Decoction. Network analysis showed that there were 20 active components involved in 114 pathways. And 16 components, 16 target proteins and 24 pathways were related to primary dysmenorrhea. Siwu Decoction may play a role in treating primary dysmenorrhea by acting on protein targets and pathways related to hormone regulation, central analgesia, spasmolysis,inflammation and immunity. This study revealed the potential active compounds and possible mechanism of Siwu Decoction for treatment of primary dysmenorrhea, providing theoretical references for further systematic laboratory experiments on effective compounds and action mechanism of Siwu Decoction.

[Dissolution behavior of Fuzi Lizhong pill based on simultaneous determination of two components in Glycyrrhizae Radix et Rhizoma].

To preliminarily investigate the dissolution behavior of Fuzi Lizhong pill, provide the basis for its quality control and lay foundation for in vivo dissolution behavior by determining the dissolution rate of liquiritin and glycyrrhizic acid. High-performance liquid chromatography (HPLC) method for simultaneous content determination of the two active ingredients of liquiritin and glycyrrhizic acid in Fuzi Lizhong pill was established; The dissolution amount of these two active ingredients in fifteen batches of Fuzi Lizhong pill from five manufacturers was obtained at different time points, and then the cumulative dissolution rate was calculated and cumulative dissolution curve was drawn. The similarity of cumulative dissolution curve of different batches was evaluated based on the same factory, and the similarity of cumulative dissolution curve of different factories was evaluated based on the same active ingredients. The dissolution model of Fuzi Lizhong pill based on two kinds of active ingredients was established by fitting with the dissolution data. The best dissolution medium was 0.25% sodium lauryl sulfate. The dissolution behavior of liquiritin and glycyrrhizic acid in Fuzi Lizhong pill was basically the same and sustained release in 48 h. Three batches of the factories (factory 2, factory 3, factory 4 and factory 5) appeared to be similar in dissolution behavior, indicating similarity in dissolution behavior in most factories. Two of the three batches from factory 1 appeared to be not similar in dissolution behavior of liquiritin and glycyrrhizic acid. The dissolution data of the effective ingredients from different factories were same in fitting, and Weibull model was the best model in these batches. Fuzi Lizhong pill in 15 batches from 5 factories showed sustained release in 48 h, proving obviously slow releasing characteristics "pill is lenitive and keeps a long-time efficacy". The generally good dissolution behavior also suggested that quality of different batches from most factories was stable. The dissolution behavior of liquiritin and glycyrrhizic acid in different factories was different, suggesting that the source of medicinal materials and preparation technology parameters in five factories were different.

Characterization of cholesterol metabolism in Sertoli cells and spermatogenesis (Review).

The Sertoli cell, which is the supporting cell of spermatogenesis, has an important role in the endocrine and paracrine control of spermatogenesis. Functionally, it provides the cells of the seminiferous epithelium with nutrition, conveys mature spermatids to the lumen of seminiferous tubules, secretes androgen­binding protein and interacts with endocrine Leydig cells. In addition, the levels of cholesterol, as well as its intermediates, vary greatly between nongonadal tissues and the male reproductive system. Throughout spermatogenesis, a dynamic and constant alteration in the membrane lipid composition of Sertoli cells occurs. In several mammalian species, testis meiosis­activating sterol and desmosterol, as well as other cholesterol precursors, accumulate in the testes and spermatozoa. In addition, certain cholesterogenic genes exhibit stage­specific expression patterns during spermatogenesis, including the cytochrome P450 enzyme lanosterol 14α­demethylase. Inconsistency in the patterns of gene expression during spermatogenesis indicates a cell­type specific and complex temporary modulation of lipids and cholesterol, which also implicates the dynamic interactions between Sertoli cells and germ cells. Furthermore, in the female reproductive tract and during epididymal transit, which is a prerequisite for valid fertilization, the modulation of cholesterol occurring in spermatozoal membranes further indicates the functional importance of sterol compounds in spermatogenesis. However, the exact role of cholesterol metabolism in Sertoli cells in sperm production is unknown. The present review article describes the progress made in the research regarding the characteristics of the Sertoli cell, particularly the regulation of its cholesterol metabolism during spermatogenesis.

Neurite Outgrowth Inhibitor B Receptor: A Versatile Receptor with Multiple Functions and Actions.

Members of the reticulon protein family are predominantly distributed within the endoplasmic reticulum. The neurite outgrowth inhibitor (Nogo) has three subtypes, including Nogo-A (200 kDa), Nogo-B (55 kDa), and Nogo-C (25 kDa). Nogo-A and Nogo-C are potent Nogos that are predominantly expressed in the central nervous system. Nogo-B, the splice variant of reticulon-4, is expressed widely in multiple human organ systems, including the liver, lung, kidney, blood vessels, and inflammatory cells. Moreover, the Nogo-B receptor (NgBR) can interact with Nogo-B and can independently affect nervous system regeneration, the chemotaxis of endothelial cells, proliferation, and apoptosis. In recent years, it has been demonstrated that NgBR plays an important role in human pathophysiological processes, including lipid metabolism, angiogenesis, N-glycosylation, cell apoptosis, chemoresistance in human hepatocellular carcinoma, and epithelial-mesenchymal transition. The pathophysiologic effects of NgBR have garnered increased attention, and the detection and enhancement of NgBR expression may be a novel approach to monitor the development and to improve the prognosis of relevant human clinical diseases.

[Analysis on dosage form theory and current application situation of traditional Chinese medicine pill].

Traditional Chinese medicine(TCM) pill, the most representative and successive dosage form, is called as one of the four classical TCM dosage forms. "Pills could keep the lasting and lenitive therapeutic efficacy for a long period" is the most classical dosage form theory, showing a guidance significance in making recipe, preparations and clinic application. In this article, we would elucidate the inheritance and development significance of TCM pills in three key points, including dosage form theory, pharmaceutical preparation technology and clinic usage based on the pharmaceutics connotation of this theory. From this, it can provide the basis for researches on pills mechanism, material basis and mode of action in clinical application.

TGF-ß Down-regulates Apolipoprotein M Expression through the TAK-1-JNK-c-Jun Pathway in HepG2 Cells.

Apolipoprotein M (apoM) is a relatively novel apolipoprotein that plays pivotal roles in many dyslipidemia-associated diseases; however, its regulatory mechanisms are poorly understood. Many cytokines have been identified that down-regulate apoM expression in HepG2 cells, among which transforming growth factor-ß (TGF-ß) exerts the most potent effects. In addition, c-Jun, a member of the activated protein 1 (AP-1) family whose activity is modulated by c-Jun N-terminal kinase (JNK), decreases apoM expression at the transcriptional level by binding to the regulatory element in the proximal apoM promoter. In this study, we investigated the molecular mechanisms through which TGF-ß decreases the apoM level in HepG2 cells. The results revealed that TGF-ß inhibited apoM expression at both the mRNA and protein levels in a dose- and time-dependent manner and that it suppressed apoM secretion. These effects were attenuated by treatment of cells with either SP600125 (JNK inhibitor) or c-Jun siRNA. 5Z-7-oxozeaenol [(a TGF-ß-activated kinase 1 (TAK-1) inhibitor)] also attenuated the TGF-ß-mediated inhibition of apoM expression and suppressed the activation of JNK and c-Jun. These results have demonstrated that TGF-ß suppresses apoM expression through the TAK-1-JNK-c-Jun pathway in HepG2 cells.

Histone Methyltransferase Enhancer of Zeste Homolog 2-Mediated ABCA1 Promoter DNA Methylation Contributes to the Progression of Atherosclerosis.

ATP-binding cassette transporter A1 (ABCA1) plays a critical role in maintaining cellular cholesterol homeostasis. The purpose of this study is to identify the molecular mechanism(s) underlying ABCA1 epigenetic modification and determine its potential impact on ABCA1 expression in macrophage-derived foam cell formation and atherosclerosis development. DNA methylation induced foam cell formation from macrophages and promoted atherosclerosis in apolipoprotein E-deficient (apoE-/-) mice. Bioinformatics analyses revealed a large CpG island (CGI) located in the promoter region of ABCA1. Histone methyltransferase enhancer of zeste homolog 2 (EZH2) downregulated ABCA1 mRNA and protein expression in THP-1 and RAW264.7 macrophage-derived foam cells. Pharmacological inhibition of DNA methyltransferase 1 (DNMT1) with 5-Aza-dC or knockdown of DNMT1 prevented the downregulation of macrophage ABCA1 expression, suggesting a role of DNA methylation in ABCA1 expression. Polycomb protein EZH2 induced DNMT1 expression and methyl-CpG-binding protein-2 (MeCP2) recruitment, and stimulated the binding of DNMT1 and MeCP2 to ABCA1 promoter, thereby promoting ABCA1 gene DNA methylation and atherosclerosis. Knockdown of DNMT1 inhibited EZH2-induced downregulation of ABCA1 in macrophages. Conversely, EZH2 overexpression stimulated DNMT1-induced ABCA1 gene promoter methylation and atherosclerosis. EZH2-induced downregulation of ABCA1 gene expression promotes foam cell formation and the development of atherosclerosis by DNA methylation of ABCA1 gene promoter.

[Serum amyloid A promotes the inflammatory response via p38-MAPK/SR-BI pathway in THP-1 macrophages].

To investigate the effect and mechanism of serum amyloid A (SAA) on the expression of scavenger receptor class B type I (SR-BI) and inflammatory response in THP-1 macrophages, the human THP-1 cells were treated with SAA and p38-MAPK agonist (anisomycin) or p38-MAPK inhibitor (SB203580). Then, the expressions of SR-BI, phosphorylated p38-MAPK and inflammatory factors (MCP-1, TNF-α, IL-1ß) were examined by real-time quantitative PCR, Western blotting and ELISA, respectively. The results showed that, compared with control group, SAA increased the levels of inflammatory factors (MCP-1, TNF-α, IL-1ß), down-regulated the expressions of SR-BI, and up-regulated the expression of phosphorylated p38-MAPK protein in a concentration- and time-dependent manner in THP-1 cells (P < 0.05). After treatment with SAA and p38-MAPK agonist (anisomycin) in THP-1 cells, the expression of SR-BI was down-regulated, and the levels of inflammatory factors and phosphorylated p38-MAPK protein expression were increased, compared with the group only treated by SAA (P < 0.05). In contrast, the SR-BI expression was up-regulated, whereas inflammatory factors and phosphorylated p38-MAPK protein expressions were decreased after the cells were treated with SAA and p38-MAPK inhibitor (SB203580) (P < 0.05). The results suggest that SAA-promoted inflammatory response in THP-1 macrophages may be through the phosphorylation of p38-MAPK and inhibition of SR-BI expression.

Betulinic acid downregulates expression of oxidative stress-induced lipoprotein lipase via the PKC/ERK/c-Fos pathway in RAW264.7 macrophages.

BACKGROUND: Atherosclerosis is a major cause of coronary artery disease, which is characterized by cellular lipid accumulation. Lipoprotein lipase (LPL) is a key enzyme in lipid metabolism. Studies have shown that macrophage-derived LPL exhibits proatherogenic properties, and plays a major role in lipid accumulation in macrophages. Evidence suggests that oxidative stress can effectively enhance macrophage LPL production. Betulinic acid (BA) is a pentacyclic lupane triterpene with a potent antioxidant activity. In this study, we investigated whether BA affects the expression of macrophage LPL and how it regulates cellular lipid accumulation. METHODS AND RESULTS: We revealed that BA downregulated H2O2-simulated macrophage LPL protein, mRNA levels and its activity in both concentration- and time-dependent manners. Furthermore, BA decreased LPL-involved total cholesterol and triglyceride levels in macrophages. In addition, cellular lipid staining by Oil Red O showed that BA decreased cellular lipid droplet deposition. Next, we confirmed that pretreatment with BA decreased H2O2-induced production of intracellular reactive oxygen species in a concentration-dependent manner. Further studies demonstrated that BA inhibited H2O2-induced membrane translocation of PKC, phosphorylation of ERK1/2 and c-Fos. Finally, the induction of LPL production and activity by H2O2 was abolished by BA, inhibition of PKC or ERK or depletion c-Fos, respectively. CONCLUSIONS: BA, through its role of antioxidant activity, attenuated macrophage-derived LPL expression and activity induced by oxidative stress, and effectively reduced cellular lipid accumulation, likely through inhibition of the pathways involving PKC, ERK and c-Fos. These effects of BA may contribute to its mitigation of atherosclerosis and help develop BA as a therapeutic compound in treatment of atherosclerosis.

Chlamydia pneumoniae negatively regulates ABCA1 expression via TLR2-Nuclear factor-kappa B and miR-33 pathways in THP-1 macrophage-derived foam cells.

OBJECTIVES: ATP-binding cassette transporter A1 (ABCA1) is critical in exporting cholesterol from macrophages and plays a protective role in the development of atherosclerosis. This study was to determine the effects and potential mechanisms of Chlamydia pneumoniae (C. pneumoniae) on ABCA1 expression and cellular cholesterol efflux in THP-1 macrophage-derived foam cells. METHODS AND RESULTS: C. pneumoniae significantly decreased the expression of ABCA1 and reduced cholesterol efflux. Furthermore, we found that C. pneumoniae suppressed ABCA1 expression via up-regulation of miR-33s. The inhibition of C. pneumoniae-induced NF-κB activation decreased miR-33s expression and enhanced ABCA1 expression. In addition, C. pneumoniae increased Toll-like receptor 2 (TLR2) expressions, inhibition of which by siRNA could also block NF-κB activation and miR-33s expression, and promot the expression of ABCA1. CONCLUSION: Taken together, these results reveal that C. pneumoniae may negatively regulate ABCA1 expression via TLR2-NF-κB and miR-33 pathways in THP-1 macrophage-derived foam cells, which may provide new insights for understanding the effects of C. pneumoniae on the pathogenesis of atherosclerosis.

[Protective effect of musk extract on rat's cerebral cortical neurons with inflammatory injury].

OBJECTIVE: To investigate the protective effects of musk extract (ME) and its possible mechanism on rat's cerebral cortical neurons with inflammatory injury induced by lipopolysaccharide (LPS). METHODS: Neurons and astrocytes from newborn rat cerebral cortex were cultured in vitro respectively, and the astrocyte conditioned medium (ACM), obtained by treating astrocytes with 10 mg/L LPS and different concentrations of ME for 24 h, was added in the culture fluid of neurons. The survival rate and apoptotic rate of neurons were measured by MTT method and AO/EB stain; and the changes of inflammatory factors in the ACM were determined by ELISA. RESULTS: The survival rate (%) of neurons treated by ACM with ME in concentrations of 18 mg/L, 36 mg/L, 72 mg/L and 144 mg/L was 52.55 +/- 3.52, 55.77 +/- 2.36, 64.89 +/- 3.45 and 73.67 +/- 1.80, respectively, significantly higher than that in the model neurons (43.62 +/- 4. 51, P < 0.05), while the apoptotic rate (%) in them, 68.11 +/- 2.16, 44.27 +/- 3.68, 32.56 +/- 2.14 and 21.89 +/- 2.46, respectively, was significantly lower than that in model neurons (71.33 +/- 3.25, P < 0.05 or P < 0.01). Level of IL-6 was decreasing along with the raising of ME concentration in the ACM, showing a concentration-dependent state. CONCLUSION: ME shows apparent protective effect on neurons against inflammatory injury, especially in a high concentration (144 mg/L), which may be associated with the reduction of IL-6 secreted by astrocytes.

Anatomic structural study of cerebellopontine angle via endoscope.

BACKGROUND: Minimally invasive surgery in skull base relying on searching for possible anatomic basis for endoscopic technology is controversial. The objective of this study was to observe the spatial relationships between main blood vessels and nerves in the cerebellopontine angle area and provide anatomic basis for lateral and posterior skull base minimally invasive surgery via endoscopic retrosigmoid keyhole approach. METHODS: This study was conducted on thirty dried adult skulls to measure the spatial relationships among the surface bony marks of posterior cranial fossa, and to locate the most appropriate drilling area for retrosigmoid keyhole approach. In addition, we used 10 formaldehyde-fixed adult cadaver specimens for simulating endoscopic retrosigmoid approach to determine the visible scope. RESULTS: The midpoint between the mastoid tip and the asterion was the best drilling point for retrosigmoid approach. A hole centered on this point with the 2.0 cm in diameter was suitable for exposing the related structures in the cerebellopontine angle. Retrosigmoid keyhole approach can decrease the pressure on the cerebellum and expose the related structures effectively which include facial nerve, vestibulocochlear nerve, trigeminal nerve, glossopharyngeal nerve, vagus nerve, accessory nerve, hypoglossal nerve, anterior inferior cerebellar artery, posterior inferior cerebellar artery and labyrinthine artery, etc. CONCLUSIONS: Exact location on endoscope retrosigmoid approach can avoid dragging cerebellum during the minimally invasive surgery. The application of retrosigmoid keyhole approach will extend the application of endoscopic technology.

[Construction of expression vector with BG2 gene and its transformation in wheat].

beta-1,3-glucanase(BG2) is one of the pathogensis-related-proteins(PR). Study of these proteins and their related genes is one of the hot points in plant genetic engineering of disease resistance for a long time. In this research, specific primers were designed with the enzyme cleavage site of Spe I in its forward one and Not I site in the backward according to the BG2 gene sequence. Using this pair of primers, BG2 gene, which was contained in the plasmid of pRTL2, was amplified and confirmed by sequencing the amplified fragment inserted into T-easy vector. The positive clone containing BG2 gene was digested with the enzymes of Spe I/Not I and then BG2 gene was inserted into the Xba I/Not I sites of super expression binary vector pATC940. The reconstructed expression vector named as pATCBG2 was introduced into the wheat of Longfumai10 and Longfumai3 (Triticum aestivum L. em. Thell) through the particle gun transformation method. The Kanamysin resistant (Km') transformants were obtained. PCR, Dot-blotting and PCR-Southern hybridization analysis showed that the BG2 gene was integrated into the genome of wheat. Result of pathogen inoculation assay on the transgenic plants showed that the transgenic plants had a higher resistant disease score of 1-2 grade than the control.