Laminaria Japonica Polysaccharides effectively inhibited the growth of nasopharyngeal carcinoma cells in vivo and in vitro study

Aims

Laminaria Japonica Polysaccharides (LJP) is a kind of plant polysaccharide isolated from Laminaria Japonica Aresch. LJP has a variety of biological activity, including anti-tumor, improving immune function, anti-radiation and others. This study observed the biological activity of LJP in vitro and in vivo on human nasopharyngeal carcinoma(NPC), and the possible anticancer mechanism was explored.

Alkyl hydroperoxide reductase: a candidate Helicobacter pylori vaccine

Helicobacter pylori (H. pylori) is the most important etiological agent of chronic active gastritis, peptic ulcer disease and gastric cancer. The aim of this study was to evaluate the efficacy of alkyl hydroperoxide reductase (AhpC) and mannosylated AhpC (mAhpC) as candidate vaccines in the C57BL/6J mouse model of H. pylori infection. Recombinant AhpC was cloned, over-expressed and purified in an unmodified form and was also engineered to incorporate N and C-terminal mannose residues when expressed in the yeast Pichia pastoris. Mice were immunized systemically and mucosally with AhpC and systemically with mAhpC prior to challenge with H. pylori. Serum IgG responses to AhpC were determined and quantitative culture was used to determine the efficacy of vaccination strategies. Systemic prophylactic immunization with AhpC/alum and mAhpC/alum conferred protection against infection in 55% and 77.3% of mice, respectively. Mucosal immunization with AhpC/cholera toxin did not protect against infection and elicited low levels of serum IgG in comparison with systemic immunization. These data support the use of AhpC as a potential vaccine candidate against H. pylori infection.     

SPF级实验兔研究进展

SPF级实验兔的研究始于1950年代末,至今已有50多年的发展历程.为更好了解国内外SPF级实验兔的发展状况,为今后的研究提供更丰富的资料,本文从SPF级实验兔的培育和饲养管理、生物学特性和应用研究三个方面进行阐述.     

SPF级实验动物屏障环境设施技术指标的检测及分析

目的:对皖南医学院SPF级实验动物屏障环境设施技术指标进行检测及分析,以确保达到保障实验动物和动物实验质量的目的。方法:以GB14925-2010为检测依据和综合判定原则,选用专业检测仪器进行屏障环境相关指标采集和评判。结果:屏障环境设施各项技术指标,如温度、相对湿度、噪声、工作照度、动物照度、换气次数、气流速度、静压差、空气洁净度、沉降菌、氨浓度等均符合国家标准。结论:皖南医学院SPF级实验动物屏障环境设施可以有力保障实验动物和动物实验的质量,为科学研究提供高品质的实验材料,确保实验结果的科学性、准确性与可重复性。     

H7 avian influenza virus vaccines protect chickens against challenge with antigenically diverse isolates

Vaccination has been a critical tool in the control of some avian influenza viruses (AIV) and has been used routinely in Pakistan to help control sporadic outbreaks of highly pathogenic (HP) H7 AIV since 1995. During that time, several AIV isolates were utilized as inactivated vaccines with varying degrees of success. In order to evaluate which H7 AIV strains may serve as optimal vaccines for diverse H7 AIVs from Pakistan we conducted vaccination-challenge studies with five H7 vaccines against challenge with two HPAIVs: A/chicken/Murree/NARC-1/1995 H7N3 and A/chicken/Karachi/SPVC-4/2004 H7N3. To further characterize the isolates antigenic cartography was used to visually demonstrate the antigenic relationships among the isolates. All vaccines provided similar protection against mortality, morbidity and shedding of challenge virus from the respiratory tract. However, some minor (not statistically significant) differences were observed and correlated with antibody levels induced by the vaccine prior to challenge.     

杭州师范大学实验动物设施的建立

杭州师范大学新建实验动物中心设有标准化的实验动物生产设施与动物实验设施，总面积3090m^2，包括大小鼠生产屏障环境、实验屏障环境和大动物实验普通环境，各项指标已通过相关部门验收并投入使用。现为浙江省实验动物从业人员实习培训基地和大动物实验基地。本文介绍该动物中心的设施建设规模和设计工艺等情况及运行过程中的一些体会。     

C-erbB-2表达、SPF与乳腺癌的预后关系

ｃｅｒｂＢ２又称ｎｅｕ或ＨＥＲ２基因,在１０％～４０％的乳腺癌病人中有扩增［１～３］,其编码为１８５ｋＤａ,具有酪氨酸激酶活性的糖蛋白,位于１７号染色体ｑ２１区带上［４］。有报道ｃｅｒｂＢ２蛋白的过度表达同乳腺癌病人较短期的无复发生存有关,尤其是对腋淋巴结阳性者［２,５,６］。在乳腺癌良性病变及正常乳腺组织中无ｃｅｒｂＢ２基因蛋白表达［７］。由于其与表皮生长因子受体（Ｅｐｉｄｅｒｍａｌｇｒｏｗｔｈｆａｃｔｏｒｒｅｃｅｐｔｏｒ,ＥＧＦＲ）近似（１７０ｋＤａ）［８,９］,人们推断它的过…     

Intestinal α-glucosidase inhibitory activity and toxicological evaluation of Nymphaea stellata flowers extract

Aim of the study

Nymphaea stellata willd. flowers (NSF) are used as a traditional medicine in India and Nepal to treat diabetic disease. Different works have demonstrated that NSF extract showed antihyperglycemic effect on alloxan-induced diabetic rats. In the present work we evaluated in vitro intestinal α-glucosidase inhibition as the possible mode of action of NSF extract on suppressing postprandial hyperglycemia for curing diabetic mellitus. In addition, NSF extract was studied to assess its possible acute oral toxicity and genotoxicity.

Materials and methods

Rat intestinal crude enzyme preparation and Caco-2 monolayer were used to evaluate α-glucosidase inhibitory activity of NSF extract. The main α-glucosidase inhibitors were detected by HPLC. For acute toxicity test, NSF extract was administered at doses of 2000, 5000 and 10,000 mg/kg body to three groups of 10 ICR mice each, and then clinical symptoms including mortality, clinical sign and gross findings were observed once a day for 14 days. In Ames test, histidine-dependent auxotrophic mutants of Salmonella typhimurium (strains TA97, TA98, TA100, TA102 and TA1535) were used and incubated in the presence and absence of S9 metabolic activation using NSF extract with concentrations of 150-5000 μg/plate. The chromosome aberration test was conducted with Chinese hamster lung (CHL) cells treated with NSF extract at doses of 150-5000 μg/ml in the presence and absence of S9 metabolic activation. In the in vivo mouse micronucleus assay, 9-week-old male and female ICR mice (n = 90, 25-30 g) were administered daily by oral gavage at doses of 2.5, 5.0 and 10.0 g/kg body for 1 or 2 days. Bone marrow smears were prepared from each treatment group 24 h after last administration and then polychromatic erythrocytes (PCEs) and normochromatic erythrocytes (NCEs) were identified.

Results

NSF extract showed potent rat intestinal α-glucosidase inhibitory activity for maltose hydrolysis with ED₅₀ value of 0.1 mg/ml. In Caco-2 monolayer, α-glucosidase activity for the maltose hydrolysis was down-regulated by NSF extract at a concentration of 0.05 mg/well level, showing 74% inhibition compared to the saline treated control. NSF was rich in phenol contents and the main α-glucosidase inhibitor, 1,2,3,4,6-penta-O-galloyl-β-d-glucose, was identified together with two phenolic compounds of gallic acid and corilagin. In acute toxicity test, NSF extract did not produce any toxic signs or deaths and the LD₅₀ value of this extract could be greater than 10,000 mg/kg body weight. These results of genotoxicity assessment showed that NSF extract did not cause genotoxic effects in Ames test, in the in vitro chromosomal aberration assay and in the in vivo micronucleus assay.

Conclusion

The current study shows that the extract from Nymphaea stellata flowers exhibits significant intestinal α-glucosidase inhibitory activity, without showing any acute toxicity or genotoxicity, which may be useful in suppressing postprandial hyperglycemia in diabetics. The results presented here suggest that the use of NSF in folk medicine as a natural antidiabetic treatment could be safe as well as beneficial.