麦冬多糖MDG-1的分离纯化和结构分析

目的分离纯化麦冬多糖抗心肌缺血的活性部位，得到相对分子质量均一的组分MDG-1，并进行结构分析。方法水提醇沉得麦冬粗多糖，超滤后经DEAE Sepharose FF柱和Sephadex G25柱色谱纯化后得MDG-1。经完全酸水解、高碘酸氧化、Smith降解、甲基化分析、¹H NMR及¹³C NMR等研究分析MDG-1的化学结构。结果和结论 MDG-1为β-D-果聚糖，易溶于水，数均分子量(M_n)为3 400，重均分子量(M_w)为4 800，峰尖分子量(M_p)为5 000，以2→1连接的呋喃型果糖为主，平均每2.8个主链残基上有一个Fruf(2→6)Fruf(2→分支)。该多糖还含有微量葡萄糖(果糖∶葡萄糖=35∶1)，可能连接在多糖的还原端。     

细脚拟青霉总多糖对人外周血单核细胞TNF-α水平及增殖活性的影响

目的提取分离细脚拟青霉总多糖 (PtPs) ,探讨其对人外周血单核细胞 (PBMC)的调节作用。方法采用水提醇沉淀法提取PtPs成分 ;用不同浓度的PtPs单独或协同脂多糖 (LPS)在体外刺激PBMC ,酶联免疫法测定TNF α的水平 ,溴化四唑蓝法测定增殖活性。结果所得PtPs制品的纯度为 76 .1% ;适当剂量的PtPs (10 0～ 5 0 0 μg/ml)能够单独或协同LPS提高PBMC对TNF α的分泌 ;还可剂量依赖性地促进PBMC的增殖活性。结论PtPs对体外培养的PBMC具有激活作用 ,可能是发挥免疫药理作用的主要活性成分。     

雷公藤多糖的提取和含量测定方法研究

目的建立雷公藤中多糖的测定方法,进行不同提取条件时,药物中多糖的含量比较.方法采用苯酚-硫酸比色法,于490nm处测定含量.结果该方法线性关系良好,平均加样回收率为100.5%,RSD＝1.23%.结论本法准确,可作为雷公藤中多糖的质量控制.     

0.8%黄精多糖滴眼液对干眼症的实验研究

目的观察0.8%黄精多糖滴眼液对实验性干眼症模型的治疗效果.方法将实验性干眼症日本大耳白兔随机分为空白对照组(模型组)、受试药物组(治疗组)和阳性药物对照组(对照组),分别用溶媒、0.8%黄精多糖滴眼液和泪然滴眼液治疗.观察Schirmer I试验和角膜结膜虎红染色点数,每周1次,共5周.结果各组模型动物Schirmer I试验滤纸湿长度和角结膜虎红染色点数分别在用药2周后和3周后差异有显著性,治疗组在用药2周后Schirmer I试验滤纸湿长明显增加,用药3周后虎红染色点数减少.结论 0.8%黄精多糖滴眼液对实验性干眼症有明显疗效.     

卡介菌多糖核酸的抗炎和抗过敏作用

目的　研究卡介菌多糖核酸 (BCG PSN)的抗炎、抗过敏作用。方法　观察对磷酸组胺所致豚鼠皮肤瘙痒的影响 ;采用二甲苯所致小鼠耳廓肿胀及角叉菜胶所致大鼠足跖肿胀实验观察抗炎作用 ;以 2 ,4 二硝基氟苯所致小鼠皮肤迟发型变态反应、大鼠同种被动皮肤过敏反应及小鼠异种被动皮肤过敏反应 ,探讨抗过敏作用。结果　豚鼠隔日肌内注射BCG PSN(0 1,0 2 ,0 4mg·kg-1) 3wk ,对磷酸组胺所致皮肤瘙痒无明显影响。小鼠隔日肌内注射BCG PSN(0 15 ,0 30 ,0 6 0mg·kg-1) 3wk ,可剂量依赖性地抑制二甲苯所致耳廓肿胀和耳异种被动皮肤过敏反应 ,高剂量时也可显著抑制 2 ,4 二硝基氟苯诱导的迟发型变态反应。大鼠隔日肌内注射BCG PSN(0 1,0 2 ,0 4mg·kg-1) 3wk ,可剂量依赖性地抑制角叉菜胶所致足跖肿胀和同种被动皮肤过敏反应。收稿日期 :2 0 0 3 -12 -2 4,修回日期 :2 0 0 4-0 2 -12作者简介 :刘桂珍 ( 1965 -) ,女 ,主管实验师 ,研究方向 :心血管药理学。Tel:0 73 1 2 3 5 5 0 77;胡长平 ( 1969-) ,男 ,博士 ,副教授 ,通迅作者 ,研究方向 :心血管药理学 ,Tel:0 73 1 2 3 5 5 0 77,E mail:huchangping2 0 0 1@yahoo .com .cn结论　BCG PSN对急性炎症、速发型变态反应和迟发型变态反应具有抑制作用。     

拟康氏木霉胞外多糖联合奥沙利铂可体外协同抑制结直肠癌细胞的增殖

目的 探讨拟康氏木霉胞外多糖（EPS）联合奥沙利铂（Oxa）用药对结肠癌细胞HCT116的协同抑制作用。方法 实验分为Control组（0 μg/mL）、Oxa组（8 μg/mL Oxa）、EPS组（100 μg/mL EPS）、EPS+Oxa组（8 μg/mL Oxa+100 μg/mL EPS）。CCK-8检测细胞活力，CompuSyn软件拟合Fa-CI曲线评价联用效果。流式检测凋亡和周期、划痕实验和transwell实验检测细胞迁移能力，Oxa和EPS相关基因与结直肠癌相关基因取交集进行PPI分析以及GO和KEGG富集分析。结果 Oxa单用或与EPS联用处理HCT116细胞，均可使HCT116细胞活力受到抑制，并呈现剂量与时间依耐性，两者联用有明显的协同作用（CI<1）。两药联用组的细胞总凋亡率与Oxa组以及对照组比较均显著升高（P<0.05）；联合用药组处于S期的比例高于其他各组。EPS和Oxa均具有抑制HCT116细胞迁移的作用，两者联用后抑制作用更为明显。KEGG分析显示主要涉及耐药、凋亡、血管新生等通路。结论 EPS联合奥沙利铂可协同抑制HCT116细胞增殖，促进该细胞凋亡和细胞S周期阻滞、抑制细胞迁移，铂耐药、PI3K-Akt、MAPK等信号通路发挥了关键作用。     

牛蒡多糖对K562细胞增殖的抑制及其机制的探讨

目的研究牛蒡多糖对K562细胞增殖的抑制作用并初步探索其机制。方法 MTT法检测牛蒡多糖对K562细胞增殖的抑制作用,RT-PCR检测BCL-2mRNA、Bax mRNA的表达。结果牛蒡多糖能明显抑制K562细胞的增殖;BCL-2基因表达下调,Bax的基因表达增多。结论牛蒡多糖对K562细胞增殖有抑制作用,其机制可能与BCL-2基因表达下调,Bax的表达上调有关。     

Lack of effectiveness of 13-valent pneumococcal conjugate vaccination against pneumococcal carriage density in Papua New Guinean infants

BackgroundPapua New Guinea (PNG) introduced the 13-valent pneumococcal conjugate vaccine (PCV13) in 2014, with administration at 1, 2, and 3 months of age. PCV13 has reduced or eliminated carriage of vaccine types in populations with low pneumococcal carriage prevalence, carriage density and serotype diversity. This study investigated PCV13 impact on serotype-specific pneumococcal carriage prevalence, density, and serotype diversity in PNG infants, who have some of the highest reported rates of pneumococcal carriage and disease in the world.MethodsNasopharyngeal swabs were collected at 1, 4 and 9 months of age from PCV13-vaccinated infants (n = 57) and age-/season-matched, unvaccinated infants (at approximately 1 month, n = 53; 4 months, n = 57; 9 months, n = 52). Serotype-specific pneumococcal carriage density and antimicrobial resistance genes were identified by qPCR and microarray.ResultsPneumococci were present in 89% of swabs, with 60 different serotypes and four non-encapsulated variants detected. Multiple serotype carriage was common (47% of swabs). Vaccine type carriage prevalence was similar between PCV13-vaccinated and unvaccinated infants at 4 and 9 months of age. The prevalence of non-vaccine type carriage was also similar between cohorts, with non-vaccine types present in three-quarters of samples (from both vaccinated and unvaccinated infants) by 4 months of age. The median pneumococcal carriage density was high and similar at each age group (~7.0 log₁₀ genome equivalents/mL). PCV13 had no effect on overall pneumococcal carriage density, vaccine type density, non-vaccine type density, or the prevalence of antimicrobial resistance genes.ConclusionPNG infants experience dense and diverse pneumococcal colonisation with concurrent serotypes from 1 month of age. PCV13 had no impact on pneumococcal carriage density, even for vaccine serotypes. The low prevalence of vaccine serotypes, high pneumococcal carriage density and abundance of non-vaccine serotypes likely contribute to the lack of PCV13 impact on carriage in PNG infants. Indirect effects of the infant PCV programs are likely to be limited in PNG. Alternative vaccines with broader coverage should be considered.     

Repeat pneumococcal polysaccharide vaccine in Indigenous Australian adults is associated with decreased immune responsiveness

BackgroundIndigenous adults residing in the Northern Territory of Australia experience elevated rates of invasive pneumococcal disease despite the routine use of 23-valent pneumococcal polysaccharide vaccine (23vPPV). We hypothesised that the limited protection from 23vPPV may be due to hyporesponsiveness as a result of vaccine failure from repeated vaccination. To explore this possibility, we evaluated the immune response to a first and second dose of 23vPPV in Indigenous adults and a first dose of 23vPPV in non-Indigenous adults.MethodsSerotype-specific IgG was measured by ELISA for all 23 vaccine serotypes at baseline and at one month post-vaccination. Individuals were considered to have an adequate immune response if paired sera demonstrated either: a four-fold rise in antibody concentration; a two-fold rise if the post vaccination antibody was >1.3 μg/ml but <4.0 μg/ml; or a post-vaccination antibody concentration >4.0 μg/ml for at least half of the serotypes tested (12/23). Our per-protocol analysis included the comparison of outcomes for three groups: Indigenous adults receiving a second 23vPPV dose (N = 20) and Indigenous (N = 60) and non-Indigenous adults (N = 25) receiving their first 23vPPV dose.ResultsAll non-Indigenous adults receiving a first dose of 23vPPV mounted an adequate immune response (25/25). There was no significant difference in the proportion of individuals with an adequate response using our definition (primary endpoint), with 88% of Indigenous adults mounted an adequate response following first dose 23vPPV (53/60) compared to 70% having an adequate response following a second dose of 23vPPV (14/20; p = 0.05). The risk difference between Indigenous participants receiving first dose compared to non-Indigenous participants receiving first dose was significant when comparing a response threshold of at least 70% (−27%, 95% CI: −43% to −11%; p = 0.01) and 90% (−38%, 95% CI: −60% to −16%; p = 0.006) of serotypes with a positive response.ConclusionIndigenous participants demonstrated a poorer response to a first dose 23vPPV compared to their non-Indigenous counterparts, with lower IgG following a second 23vPPV dose. These findings highlight the critical need to evaluate the efficacy of future pneumococcal vaccine programs in the Australian Indigenous populations that recommend repeated doses of 23vPPV.