• 제목/요약/키워드: Li Gao

검색결과 442건 처리시간 0.025초

Heterologous Expression of Rhizopus Oryzae CYP509C12 Gene in Rhizopus Nigricans Enhances Reactive Oxygen Species Production and 11α-Hydroxylation Rate of 16α, 17-Epoxyprogesterone

  • Shen, Chaohui;Gao, Xiyang;Li, Tao;Zhang, Jun;Gao, Yuqian;Qiu, Liyou;Zhang, Guang
    • Mycobiology
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    • 제47권3호
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    • pp.301-307
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    • 2019
  • The $11{\alpha}$-hydroxylation of $16{\alpha}$, 17-epoxyprogesterone (EP) catalyzed by Rhizopus nigricans is crucial for the steroid industry. However, lower conversion rate of the biohydroxylation restricts its potential industrial application. The $11{\alpha}$-steroid hydroxylase CYP509C12 from R. oryzae were reported to play a crucial role in the $11{\alpha}$-hydroxylation in recombinant fission yeast. In the present study, the CYP509C12 of R. oryzae (RoCYP) was introduced into R. nigricans using the liposome-mediated mycelial transformation. Heterologous expression of RoCYP resulted in increased fungal growth and improved intracellular reactive oxygen species content in R. nigricans. The $H_2O_2$ levels in RoCYP transformants were approximately 2-folder that of the R. nigricans wild type (RnWT) strain, with the superoxide dismutase activities increased approximately 45% and catalase activities decreased approximately 68%. Furthermore, the $11{\alpha}$-hydroxylation rates of EP in RoCYP transformants (C4, C6 and C9) were 39.7%, 38.3% and 38.7%, which were 12.1%, 8.2% and 9.4% higher than the rate of the RnWT strain, respectively. This paper investigated the effect of heterologous expression of RoCYP in R. nigricans, providing an effective genetic method to construct the engineered strains for steroid industry.

Characteristics of the Infection of Tilletia laevis Kuhn (syn. Tilletia foetida (Wallr.) Liro.) in Compatible Wheat

  • Ren, Zhaoyu;Zhang, Wei;Wang, Mengke;Gao, Haifeng;Shen, Huimin;Wang, Chunping;Liu, Taiguo;Chen, Wanquan;Gao, Li
    • The Plant Pathology Journal
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    • 제37권5호
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    • pp.437-445
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    • 2021
  • Tilletia laevis Kuhn (syn. Tilletia foetida (Wallr.) Liro.) causes wheat common bunt, which is one of the most devastating plant diseases in the world. Common bunt can result in a reduction of 80% or even a total loss of wheat production. In this study, the characteristics of T. laevis infection in compatible wheat plants were defined based on the combination of scanning electron microscopy, transmission electron microscopy and laser scanning confocal microscopy. We found T. laevis could lead to the abnormal growth of wheat tissues and cells, such as leakage of chloroplasts, deformities, disordered arrangements of mesophyll cells and also thickening of the cell wall of mesophyll cells in leaf tissue. What's more, T. laevis teliospores were found in the roots, stems, flag leaves, and glumes of infected wheat plants instead of just in the ovaries, as previously reported. The abnormal characteristics caused by T. laevis may be used for early detection of this pathogen instead of molecular markers in addition to providing theoretical insights into T. laevis and wheat interactions for breeding of common bunt resistance.

Ruptured Spinal Dermoid Cysts with Lipid Droplets into the Syrinx Cavity : Reports of Fourteen Cases

  • Cheng, Cheng;Li, Rong;Gao, Haihao;Tao, Benzhang;Wang, Hui;Sun, Mengchun;Gao, Gan;Wang, Jianzhen;Shang, Aijia
    • Journal of Korean Neurosurgical Society
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    • 제65권3호
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    • pp.430-438
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    • 2022
  • Objective : Dermoid cysts are uncommon in spinal cord tumors, and the phenomenon of their spontaneous rupture into the syrinx cavity is quite rare. We aimed to analyze the imaging characteristics and etiologies, and propose some surgical strategies, for this uncommon phenomenon. Methods : We retrospectively reviewed 14 cases with spinal dermoid cysts that ruptured into the cervical and thoracic syrinx cavity. There were six male and eight female cases, aged 21 to 46 years, who had lipid droplets in the syrinx cavity from C1 to L3. The dermoid cysts were always located at the conus. Based on patients' complaints, clinical manifestations, and imaging results, we adopted tumor excision and/or syrinx cavity aspiration in one stage or multiple stages. Results : Three patients had only a syrinx cavity aspiration surgery due to a history of dermoid cyst excision. Eight patients had dermoid cyst resection and syrinx cavity aspiration in one stage. One patient was operated upon in two stages due to the development of new symptoms at nine months follow-up. Two patients underwent only tumor resection since they did not show similar symptoms or signs caused by the cervicothoracic syrinx. The axial magnetic resonance imaging indicated that the lipid droplets were always not at the center but were eccentric. The clinical effect was satisfactory during the follow-up period in this group. Conclusion : The lipid droplets filled the spinal syrinx cavity, not entirely confined to the central canal. Based on the chief complaints and associated signs, we adopted different surgical strategies and had satisfactory clinical results.

A Multi-center Survey of HPV Knowledge and Attitudes Toward HPV Vaccination among Women, Government Officials, and Medical Personnel in China

  • Zhao, Fang-Hui;Tiggelaar, Sarah M.;Hu, Shang-Ying;Zhao, Na;Hong, Ying;Niyazi, Mayinuer;Gao, Xiao-Hong;Ju, Li-Rong;Zhang, Li-Qin;Feng, Xiang-Xian;Duan, Xian-Zhi;Song, Xiu-Ling;Wang, Jing;Yang, Yun;Li, Chang-Qin;Liu, Jia-Hua;Liu, Ji-Hong;Lu, Yu-Bo;Li, Li;Zhou, Qi;Liu, Jin-Feng;Xu, Li-Na;Qiao, You-Lin
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권5호
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    • pp.2369-2378
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    • 2012
  • Objectives: To assess knowledge of HPV and attitudes towards HPV vaccination among the general female population, government officials, and healthcare providers in China to assist the development of an effective national HPV vaccination program. Methods: A cross-sectional epidemiologic survey was conducted across 21 urban and rural sites in China using a short questionnaire. 763 government officials, 760 healthcare providers, and 11,681 women aged 15-59 years were included in the final analysis. Data were analyzed using standard descriptive statistics and logistic regression. Results: Knowledge of HPV among the general female population was low; only 24% had heard of HPV. Less than 20% of healthcare providers recognized sexually na$\ddot{i}$ve women as the most appropriate population for HPV vaccination. There was high acceptance of the HPV vaccine for all categories of respondents. Only 6% of women were willing to pay more than US $300 for the vaccine. Conclusions: Aggressive education is necessary to increase knowledge of HPV and its vaccine. Further proof of vaccine safety and efficacy and government subsidies combined with increased awareness could facilitate development and implementation of HPV vaccination in China.

Association of CAST Gene Polymorphisms with Carcass and Meat Quality Traits in Chinese Commercial Cattle Herds

  • Li, Jiao;Zhang, Lu-Pei;Gan, Qian-Fu;Li, Jun-Ya;Gao, Hui-Jiang;Yuan, Zheng-Rong;Gao, Xue;Chen, Jin-Bao;Xu, Shang-Zhong
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권11호
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    • pp.1405-1411
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    • 2010
  • Calpastatin (CAST), an endogenous inhibitor of the calpains, plays an important role in post-mortem tenderization of meat. The objectives of this study were to investigate single nucleotide polymorphisms (SNPs) in the bovine CAST gene and association with carcass and meat quality traits. A total of 212 cattle from commercial herds were tested in this study including 2 pure introduced breeds, 4 cross populations, and 3 pure Chinese native breeds. Five SNPs were identified at position 2959 (A/G), 2870 (G/A), 3088 (C/T), 3029 (G/A) and 2857 (C/T) in the CAST gene (GenBank Accession No. AF159246). Allele frequencies of SNP2959 and SNP2870 were 0.701 (A) and 0.462 (A), respectively. A general linear model was used to evaluate the associations between the two markers and 7 traits. The results showed that both SNP2959 and SNP2870 were significantly (p<0.01) associated with the Warner-Bratzler shear force (WBSF), while they had no significant association with the other 6 traits in the whole population. However, in Chinese native pure breeds, only SNP2870 had significant association with WBSF (p<0.05). The simultaneous analysis of two-marker genotype effects indicated animals containing the A/G haplotype (A for SNP2959 and G for SNP2870) tended to have lower shear force than those containing the G/A haplotype, and, especially, animals homozygous for the A/G haplotype had approximately 2 kg lower shear force than those homozygous for the G/A haplotype (p<0.01). These results suggested that both markers may be effective for the marker-assisted selection of meat quality traits in Chinese commercial herds, especially SNP2870 which can be used for Chinese native cattle.

Clinical Risk Factor Analysis for Breast Cancer: 568,000 Subjects Undergoing Breast Cancer Screening in Beijing, 2009

  • Pan, Lei;Han, Li-Li;Tao, Li-Xin;Zhou, Tao;Li, Xia;Gao, Qi;Wu, Li-Juan;Luo, Yan-Xia;Ding, Hui;Guo, Xiu-Hua
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권9호
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    • pp.5325-5329
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    • 2013
  • Objectives: Although there are many reports about the risk of breast cancer, few have reported clinical factors including history of breast-related or other diseases that affect the prevalence of breast cancer. This study explores these risk factors for breast cancer cases reported in Beijing in 2009. Materials and Methods: Data were derived from a Beijing breast cancer screening performed in 2009, of 568,000 women, from 16 districts of Beijing, all aged between 40 and 60 years. In this study, multilevel statistical modeling was used to identify clinical factors that affect the prevalence of breast cancer and to provide more reliable evidence for clinical diagnostics by using screening data. Results and Conclusion: Those women who had organ transplants, compared with those with none, were associated with breast cancer with an odds ratio (OR)=65.352 [95% confidence interval (CI): 8.488-503.165] and those with solid breast mass compared with none had OR=1.384 (95% CI: 1.022-1.873). Malignant tendency was strongly associated with increased risk of breast cancer, OR=207.999(95% CI: 151.950-284.721). The risk of breast cancer increased with age, $OR_1$=2.759 (95% CI: 1.837-4.144, 56-60 vs. 40-45), $OR_2$=2.047 (95% CI: 1.394-3.077, 51-55 vs. 40-45), $OR_3$=1.668 (95% CI: 1.145-2.431). Normal results of B ultrasonic examination show a lower risk among participants, OR= 0.136 (95% CI: 0.085-0.218). Those women with ductal papilloma compared with none were associated with breast cancer, OR=6.524 (95% CI: 1.871-22.746). Therefore, this study suggests that clinical doctors should pay attention to these high-risk factors.

Synthesis and Biological Evaluation of Heterocyclic Ring-substituted Chalcone Derivatives as Novel Inhibitors of Protein Tyrosine Phosphatase 1B

  • Chen, Zhen-Hua;Sun, Liang-Peng;Zhang, Wei;Shen, Qiang;Gao, Li-Xin;Li, Jia;Piao, Hu-Ri
    • Bulletin of the Korean Chemical Society
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    • 제33권5호
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    • pp.1505-1508
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    • 2012
  • Protein tyrosine phosphatase 1B (PTP1B) is a key factor in negative regulation of the insulin pathway, and is a promising target for the treatment of type-II diabetes, obesity and cancer. Herein, compound ($\mathbf{4}$) was first observed to have moderate inhibitory activity against PTP1B with an $IC_{50}$ value of $13.72{\pm}1.53{\mu}M$. To obtain more potent PTP1B inhibitors, we synthesized a series of chalcone derivatives using compound ($\mathbf{4}$) as the lead compound. Compound $\mathbf{4l}$ ($IC_{50}=3.12{\pm}0.18{\mu}M$) was 4.4-fold more potent than the lead compound $\mathbf{4}$ ($IC_{50}=13.72{\pm}1.53{\mu}M$), and more potent than the positive control, ursolic acid ($IC_{50}=3.40{\pm}0.21{\mu}M$). These results may help to provide suitable drug-like lead compounds for the design of inhibitors of PTP1B as well as other PTPs.

Involvement of Estrogen Receptor-α in the Activation of Nrf2-Antioxidative Signaling Pathways by Silibinin in Pancreatic β-Cells

  • Chu, Chun;Gao, Xiang;Li, Xiang;Zhang, Xiaoying;Ma, Ruixin;Jia, Ying;Li, Dahong;Wang, Dongkai;Xu, Fanxing
    • Biomolecules & Therapeutics
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    • 제28권2호
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    • pp.163-171
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    • 2020
  • Silibinin exhibits antidiabetic potential by preserving the mass and function of pancreatic β-cells through up-regulation of estrogen receptor-α (ERα) expression. However, the underlying protective mechanism of silibinin in pancreatic β-cells is still unclear. In the current study, we sought to determine whether ERα acts as the target of silibinin for the modulation of antioxidative response in pancreatic β-cells under high glucose and high fat conditions. Our in vivo study revealed that a 4-week oral administration of silibinin (100 mg/kg/day) decreased fasting blood glucose with a concurrent increase in levels of serum insulin in high-fat diet/streptozotocin-induced type 2 diabetic rats. Moreover, expression of ERα, NF-E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) in pancreatic β-cells in pancreatic islets was increased by silibinin treatment. Accordingly, silibinin (10 μM) elevated viability, insulin biosynthesis, and insulin secretion of high glucose/palmitate-treated INS-1 cells accompanied by increased expression of ERα, Nrf2, and HO-1 as well as decreased reactive oxygen species production in vitro. Treatment using an ERα antagonist (MPP) in INS-1 cells or silencing ERα expression in INS-1 and NIT-1 cells with siRNA abolished the protective effects of silibinin. Our study suggests that silibinin activates the Nrf2-antioxidative pathways in pancreatic β-cells through regulation of ERα expression.

Induction of Apoptosis in Glioma Cells and Upregulation of Fas Expression Using the Human Interferon-β Gene

  • Guo, Yan;Wang, Gan;Gao, Wen-Wei;Cheng, Shi-Wen;Wang, Ren;Ju, Shi-Ming;Cao, He-Li;Tian, Heng-Li
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권6호
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    • pp.2837-2840
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    • 2012
  • We investigated whether IFN-${\beta}$ inhibits the growth of human malignant glioma and induces glioma cell apoptosis using the human IFN-${\beta}$ gene transfected into glioma cells. A eukaryonic expression vector ($pSV2IFN{\beta}$) for IFN-${\beta}$ was transfected into the glioma cell line SHG44 using liposome transfection. Stable transfection and IFN-${\beta}$ expression were confirmed using an enzyme-linked immunosorbent assay (ELISA). Cell apoptosis was also assessed by Hoechst staining and electron microscopy. In vivo experiments were used to establish a SHG44 glioma model in nude mice. Liposomes containing the human IFN-${\beta}$ gene were injected into the SHG44 glioma of nude mice to observe glioma growth and calculate tumor size. Fas expression was evaluated using immunohistochemistry. The IFN-${\beta}$ gene was successfully transfected and expressed in the SHG44 glioma cells in vitro. A significant difference in the number of apoptotic cells was observed between transfected and non-transfected cells. Glioma growth in nude mice was inhibited in vivo, with significant induction of apoptosis. Fas expression was also elevated. The IFN-${\beta}$ gene induces apoptosis in glioma cells, possibly through upregulation of Fas. The IFN-${\beta}$ gene modulation in the Fas pathway and apoptosis in glioma cells may be important for the treatment of gliomas.

EGF Reverses Multi-drug Resistance via the p-ERK Pathway in HepG2/ADM and SMMC7721/ADM Hepatocellular Carcinoma Models

  • Yan, Feng;Bai, Li-Ping;Gao, Hua;Zhu, Chang-Ming;Lin, Li;Kang, Xiang-Peng
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권6호
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    • pp.2619-2623
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    • 2014
  • Aim: To investigate signaling pathways for reversal of EGF-mediated multi-drug resistance (MDR) in hepatocellular carcinoma (HCC) models. Materials and Methods: HCC MDR cell strain HepG2/adriamycin (ADM) and SMMC7721/ADM models were established using a method of exposure to medium with ADM between low and high concentration with gradually increasing concentration. Drug sensitivity and reversal of multi-drug resistance by EGF were determined and the cell cycle distribution and apoptosis were analyzed by flow cytometry. Phosphorylation of ERK1, ERK2, ERK5 and expression of Bim were detected by Western blotting. Results: The results showed that HepG2/ADM and SMMC7721/ADM cells were resistant not only to ADM, but also to multiple anticancer drugs. When used alone, EGF had no anti-tumor activity in HepG2/ADM and SMMC7721/ADM cells in vitro, while it increased the cytotoxicity of ADM. EGF induced cell apoptosis and G0/G1 phase cell cycle arrest in HepG2/ADM And SMMC7721/ADM cells, while enhancing activity of p-ERKs and up-regulated expression of BimEL. Conclusions: EGF might enhance the chemosensitivity of HepG2/ADM and SMMC7721/ADM cells via up-regulating p-ERKs and BimEL protein.