蝉拟青霉多糖对免疫抑制大鼠脾细胞促增殖作用及其机制的研究

自从1969年13本学者千原首次报道香菇多糖具有抗肿瘤活性以后，真菌多糖引起越来越多的关注，成为一个非常活跃的研究领域。人们研究发现真菌多糖有很多重要生物学活性，而其中以免疫学活性最为重要，并且常作为一种免疫调节剂。真菌多糖不仅能激活T细胞、B细胞、巨噬细胞（Mφ）、自然杀伤细胞（NK）等免疫细胞，     

甲壳素及其衍生物的生物活性和医学应用

本文简要总结了国内外甲壳素类多糖的生物活性肥及在医学上的应用研究结果，这些结果表明，甲壳素一类性能优异的生物材料，在医学方面具有广阔的应用前景。     

激光生物刺激作用与多糖生物活性的比较研究

本文从生物信息传导的角度比较了激光生物刺激作用民多糖生物活性，揭示了它们的相似性及其在开发亲的弱激光疗法方面的应用。     

生药活性多糖对淋巴细胞／细胞素的调节与抗肿瘤作用

生药活性多糖基本上是由D型和/或L型单糖组成的有一定空间构型的葡聚糖构成,含有少量蛋白质和微量元素。一些补益类中药的活性多糖如黄芪多糖、枸杞子多糖、香菇多糖、刺五加多糖等都有一定的免疫增强作用。在一定的剂量范围内,生药多糖在体内能非特异性增强机体免疫功能,增强机体的抗肿瘤作用,在体外参与活化免疫细胞,促进某些细胞因子的分泌。几种生药皂甙如人参皂甙、中国商陆皂甙都有很强的免疫增强作用。本文拟对此做一简要报道。一、生药活性多糖对活化T细胞和增强某些细胞素分泌的调节作用1.香菇多糖(Lentinan)香菇多糖是以直链β-1,3-葡萄糖基的5位有两个β-1,6-葡萄糖侧链为基本骨架的β-1,3-D-葡聚糖,具有右旋三垂螺旋结构,分子量为40万—80     

羟基磷灰石在口腔保健领域的应用

本文通过分析羟基磷灰石的生物活性和作用原理，结合龋齿等口腔疾病的发生原因，对这种生物活性材料在预防龋齿、炎症、溃疡和牙齿美白等口腔保健领域中的应用做一综述。     

蛹虫草多糖免疫调节机制的研究进展

蛹虫草多糖（CMP）是蛹虫草的主要生物活性成分，具有免疫调节、抗肿瘤、降血糖等多种生物活性功能。本文综述了CMP主要通过细胞因子、自然杀伤细胞、T/B淋巴细胞和巨噬细胞等发挥免疫调节机制的作用，同时也介绍了CMP抗肿瘤及抗炎、降血糖等作用的新进展。     

自制黄芪多糖对鸡免疫功能的影响

黄芪是祖国传统医学中最常用的补气药之一，其性甘、微苦，人肺、脾经，具有补气升阳、固表止汗、托毒生肌等功能。它含有多糖、生物碱、氨基酸、黄酮类等多种生物活性物质。其中黄芪多糖（Astragalus Polysaccharides，APS）是黄芪的主要生物活性成分，并且黄芪多糖的免疫活性尤为突出。现代医学研究表明，黄芪多糖除能增强机体免疫功能，促进细胞代谢，调节DNA、RNA和蛋白质的合成外，还兼有固肾降压、保肝消炎等功效。     

岩藻聚糖硫酸酯衍生物的研究进展

岩藻聚糖硫酸酯是一种硫酸多糖,具有多种生物活性.多糖化学修饰可提高多糖活性或使多糖产生新的活性.作者对岩藻聚糖硫酸酯衍生物的制备工艺和活性等进行了综述,包括低分子衍生物、脱硫衍生物、过硫酸化衍生物、乙酰化衍生物、苯酰化衍生物、磷酸化衍生物和氨基化衍生物等,以期促进岩藻聚糖硫酸酯的研究,获得高效、新型多糖药物.     

具有生物活性的高导复合支架材料制备表征及其生物相容性☆

背景：组织工程新材料必须既能支持组织生长,又能激发理想的细胞反应(如血管发生),而导电性则可促进包括神经在内的组织再生。 目的：构建一种新型材料,能将导电性和生物活性有效的结合起来,为组织工程提供一种理想的备选材料。 方法：将具有生物活性的透明质酸多糖和导电聚合物聚吡咯进行结合,制备具有生物活性的导电聚合物复合材料。 结果与结论：含有透明质酸多糖的聚吡咯/透明质酸双层膜具有光滑的表面形貌和良好的导电性。体外细胞相容性实验显示这种复合材料可显著促进神经轴突的延伸。体内实验显示该复合材料还具有良好的惰性和促血管生成效应,是一种较为理想的组织工程备选材料。     

A-W生物活性玻璃陶瓷的研究和发展

生物活性玻璃陶瓷和玻璃陶瓷是生物医用材料领域的一个重要研究方向，其生物活性使材料被植入后能与骨形成紧密的化学键结合。A-W(Apatite／Wollastonite)生物活性玻璃陶瓷作为此类材料的杰出代表，不但拥有出色的生物活性和生物相容性，还具有优异的力学性能，因此在临床上得到了大量应用和发展。本文主要介绍了A-W生物活性玻璃陶瓷的研究进展、研制方法、性能、应用及骨结合机理，并对A-W生物活性玻璃陶瓷的研究和发展作出了展望。     

Characterization of polysaccharides from the flowers of Nerium indicum and their neuroprotective effects

Degeneration of neurons is a key problem in Alzheimer's disease (AD) and neuroprotection is a possible way to safeguard neurons from neurodegeneration. Polysaccharides isolated from Chinese medicinal herbs have been investigated extensively for their anti-tumor and immune stimulating effects. Yet, little is known about the effects of polysaccharides in neurons. Recently, two pure polysaccharides isolated from the flowers of Nerium indicum were shown to stimulate proliferation and differentiation of PC12 pheochromocytoma cells, an effect similar to that observed from nerve growth factor. In this notion, it is hypothesized that polysaccharides isolated from the flowers of N. indicum could exhibit beneficial effects in neurons. In this study, we isolated, characterized and investigated two new polysaccharides from the flowers of N. indicum for their neuroprotective effects on neurons against serum-deprivation and beta-amyloid (Abeta) peptide toxicity in primary rat cortical neuronal cultures. Pretreatment of the polysaccharides significantly reduced the number of apoptotic neurons revealed by DAPI staining when neurons were exposed to serum-free medium. Besides, the polysaccharides could also decrease the activity of caspase-3 triggered by Abeta peptides. Western blot analysis indicated that polysaccharides stimulated the phosphorylation of PDK-1 (Serine 241) and Akt (Threonine 308). In conclusion, the polysaccharides J2, J3 and J4 isolated from N. indicum provide a lead for future development of neuroprotective agent against neuronal death in neurodegenerative diseases and the neuroprotective mechanism may primarily rely on activation of Akt survival signaling pathway.     

Comparison of the induction of immunoglobulin M and G antibodies in mice with purified pneumococcal type 3 and meningococcal group C polysaccharides and their protein conjugates.

The nature and kinetics of the serum antibody response to pneumococcal type 3 and meningococcal group C polysaccharides and their protein conjugates were studied in mice. Bovine serum albumin and diphtheria and tetanus toxoids were used as carrier proteins. The purified polysaccharides induced only immunoglobulin M (IgM) antibodies in thymus-bearing as well as congenic athymic (nude) mice. The polysaccharides covalently conjugated to proteins produced IgM and IgG antibodies in normal mice, but only IgM antibodies in nude mice. A second dose of the polysaccharide-protein conjugates resulted in a booster effect in the IgG response to the polysaccharides. Moreover, memory B-cells, generated after a primary injection with the polysaccharide-protein conjugates, could be triggered to the production of IgG antibodies after a second injection with the pure polysaccharides alone. These data indicate that the antibody response to the pure polysaccharides is thymus independent and that this response can be changed into a thymus-dependent response by covalent conjugation of the polysaccharide to a thymus-dependent protein.     

Pneumococcal Conjugate Vaccines Overcome Splenic Dependency of Antibody Response to Pneumococcal Polysaccharides

Protection against infections with Streptococcus pneumoniae depends on the presence of antibodies against capsular polysaccharides that facilitate phagocytosis. Asplenic patients are at increased risk for pneumococcal infections, since both phagocytosis and the initiation of the antibody response to polysaccharides take place in the spleen. Therefore, vaccination with pneumococcal polysaccharide vaccines is recommended prior to splenectomy, which, as in the case of trauma, is not always feasible. We show that in rats, vaccination with a pneumococcal conjugate vaccine can induce good antibody responses even after splenectomy, particularly after a second dose. The spleen remains necessary for a fast, primary response to (blood-borne) polysaccharides, even when they are presented in a conjugated form. Coadministration of a conjugate vaccine with additional nonconjugated polysaccharides of other serotypes did not improve the response to the nonconjugated polysaccharides. We conclude that pneumococcal conjugate vaccines can be of value in protecting asplenic or hyposplenic patients against pneumococcal infections.     

The symbiotic defect in a Sinorhizobium meliloti lipopolysaccharide mutant can be overcome by expression of other surface polysaccharides

In this work we have examined the extent of functional complementation in symbiosis among different Sinorhizobium meliloti surface polysaccharides including lipopolysaccharide (LPS).We show that a symbiotic deficiency associated with an LPS defect can be reversed by appropriate expression of other surface polysaccharides such as galactoglucan (EPSII) and a particular form of capsular polysaccharide (KdoPS). It is noteworthy that, while succinoglycan EPSI and LPS cannot functionally substitute for each other, they can both be replaced by the same common set of polysaccharides (i.e., EPSII/KdoPS). The complex pattern of functional complementation in symbiosis among S. meliloti surface polysaccharides was shown to be different in Medicago truncatula compared to that previously reported for M. sativa.     

Modification of lymphocyte migration by sulfated polysaccharides

The role of sulfated polysaccharides in lymphocyte migration has been analyzed in vivo using lymphocytes labeled with an intracellular DNA-binding fluorochrome Hoechst 33342. The influence of a panel of sulfated polysaccharides on entry (by injecting the sulfated polysaccharide prior to the labeled cells) and displacement from lymphoid organs (by injecting the sulfated polysaccharide after the labeled cells have localized) indicated that different sulfated polysaccharides have selective effects on entry and displacement, and furthermore positioning of subpopulations within organs. Additional experiments suggested that receptors for sulfated polysaccharides on high endothelial venules may interact with complementary structures on lymphocytes. The data supporting this conclusion were: (a) the normal localization behavior of lymphocytes preincubated with sulfated polysaccharides; (b) an inverse relationship between the expression of lymphocyte surface receptors for sulfated polysaccharides and the ability of the lymphocytes to enter lymphoid organs and (c) the selective binding of sulfated polysaccharide-coupled fluoresceinated beads to high endothelial venules. In this case only the beads coupled with the sulfated polysaccharides that inhibited entry bound to the high endothelial venules. These findings are discussed in terms of a fundamental cellular recognition system utilizing sulfated polysaccharides.     

当归多糖对小鼠腹腔巨噬细胞释放细胞效应分子的诱导作用

目的 :观察当归多糖对小鼠腹腔巨噬细胞产生细胞毒效应分子的影响。方法 :从BALB/c小鼠的腹腔分离巨噬细胞 ,并进行原代细胞培养。采用MTT比色法及紫外分光光度法 ,检测当归多糖对腹腔巨噬细胞释放一氧化氮 (NO)、肿瘤坏死因子α(TNF α)、活性氧 (ROS)以及诱导型一氧化氮合酶 (iNOS)和溶菌酶 (LSZ)活性的影响。结果 :当归多糖可激活巨噬细胞释放NO、TNF α和ROS等效应分子 ,并显著提高LSZ的活性。当归多糖可能通过提高巨噬细胞iNOS的活性而增加NO的释放量 ,但其与脂多糖 (LPS)无协同促进NO释放的作用。当归多糖体外无直接杀伤肿瘤细胞的作用 ,但其与巨噬细胞共孵育的培养上清具有杀伤L92 9细胞的作用。结论 :当归多糖可促进巨噬细胞释放NO、TNF α及ROS等细胞效应分子 ,并可通过作用于巨噬细胞而促进TNF α的分泌 ,发挥间接的抗肿瘤免疫作用     

Structural and antigenic types of cell wall polysaccharides from viridans group streptococci with receptors for oral actinomyces and streptococcal lectins.

Lectin-mediated interactions between oral viridans group streptococci and actinomyces may play an important role in microbial colonization of the tooth surface. The presence of two host-like motifs, either GalNAc beta1-->3Gal (Gn) or Gal beta1-->3GalNAc (G), in the cell wall polysaccharides of five streptococcal strains accounts for the lactose-sensitive coaggregations of these bacteria with Actinomyces naeslundii. Three streptococcal strains which have Gn-containing polysaccharides also participate in GalNAc-sensitive coaggregations with strains of Streptococcus gordonii and S. sanguis. Each Gn- or G-containing polysaccharide is composed of a distinct phosphodiester-linked hexa- or heptasaccharide repeating unit. The occurrence of these polysaccharides on 19 additional viridans group streptococcal strains that participate in lactose-sensitive coaggregations with actinomyces was examined. Negatively charged polysaccharides that reacted with Bauhinia purpurea agglutinin, a Gal and GalNAc binding plant lectin, were isolated from 17 strains by anion exchange column chromatography of mutanolysin-cell wall digests. Results from nuclear magnetic resonance and immunodiffusion identified each of 16 polysaccharides as a known Gn- or G-containing structural type and one polysaccharide as a new but closely related Gn-containing type. Unlike the reactions of lectins, the cross-reactions of most rabbit antisera with these polysaccharides were correlated with structural features other than the host-like motifs. Gn-containing polysaccharides occurred primarily on the strains of S. sanguis and S. oralis while G-containing polysaccharides were more common among the strains of S. gordonii and S. mitis examined. The findings strongly support the hypothesis that lectin-mediated recognition of these streptococci by other oral bacteria depends on a family of antigenically diverse Gn- and G-containing cell wall polysaccharides, the occurrence of which may differ between streptococcal species.     

Corynebacterium parvum augments antibody production in splenectomized mice and mice with sham operations

The antibody response to a variety of antigens, including pneumococcal polysaccharides, is diminished in splenectomized (splx) mice. We investigated the capacity for the biological response modifier Corynebacterium parvum to augment antibody production in splx and sham-splx mice inoculated with pneumococcal polysaccharides and tetanus toxoid. As expected, antibody response to tetanus toxoid was similar in both splx mice and sham-splx mice. C. parvum augmented anti-tetanus toxoid antibody in both sham-splx (P less than 0.05) and splx mice (P less than 0.05). Antibody against pneumococcal type 3 polysaccharides was decreased in splx mice compared with sham-splx mice (P less than 0.05). Both groups treated coincidently with C. parvum and pneumococcal type 3 polysaccharides demonstrated a biphasic antibody response which was greater than that observed in saline-treated controls (sham-splx, P less than 0.001; splx, P less than 0.05). Whereas the secondary peak response to pneumococcal type 3 polysaccharides after treatments with C. parvum appears to be due to persistent elevations of immunoglobulin G and immunoglobulin M in sham-splx mice, it is primarily due to antibody of the immunoglobulin G class alone in the splx mice.     

Immunochemical and biological characterization of three capsular polysaccharides from a single Bacteroides fragilis strain

Although Bacteroides fragilis accounts for only 0.5% of the normal human colonic flora, it is the anaerobic species most frequently isolated from intra-abdominal and other infections with an intestinal source. The capsular polysaccharides of B. fragilis are part of a complex of surface polysaccharides and are the organism's most important virulence factors in the formation of intra-abdominal abscesses. Two capsular polysaccharides from strain NCTC 9343, PS A1 and PS B1, have been characterized structurally. Their most striking feature is a zwitterionic charge motif consisting of both positively and negatively charged substituent groups on each repeating unit. This zwitterionic motif is essential for abscess formation. In this study, we sought to elucidate structural features of the capsular polysaccharide complex of a commonly studied B. fragilis strain, 638R, that is distinct from strain 9343. We sought a more general picture of the species to establish basic structure-activity and structure-biosynthesis relationships among abscess-inducing polysaccharides. Strain 638R was found to have a capsular polysaccharide complex from which three distinct carbohydrates could be isolated by a complex purification procedure. Compositional and immunochemical studies demonstrated a zwitterionic charge motif common to all of the capsular polysaccharides that correlated with their ability to induce experimental intra-abdominal abscesses. Of interest is the range of net charges of the isolated polysaccharides-from positive (PS C2) to balanced (PS A2) to negative (PS 3). Relationships among structural components of the zwitterionic polysaccharides and their molecular biosynthesis loci were identified.     

植物多糖对巨噬细胞免疫功能的影响

植物多糖的作用机理与天然免疫调节,尤其是巨噬细胞的功能有关.总的来说,植物多糖首要作用是通过与巨噬细胞表面特异性受体的结合,进而增强和/或激活巨噬细胞免疫应答反应,从而起到免疫调节、抗肿瘤、促进创伤愈合及其它治疗作用.因此,研究植物多糖对巨噬细胞的免疫调节机制对于植物多糖功能的研究具有重要的参考价值.