Preparation of tritium‐labeled Silybin—a protectant for common liver diseases

Silymarin, the seed extract of milk thistle plant, Silybum marianum, has been used traditionally for the treatment of liver diseases and bile duct infection. Silybin 1 is the main bioactive components of silymarin, consisting a pair of diastereomers: Silybin A and Silybin B. In this article, we report the preparation of tritium‐labeled Silybin, which was accomplished by protection of Silybin as tritylated compound 2 and followed by oxidation of the primary alcohol to its corresponding aldehyde 3 . Subsequent reduction with NaB[³H]₄ and deprotection of the trityl group provided the tritium‐labeled Silybin 4 . Copyright © 2006 John Wiley & Sons, Ltd.     

Intranasal treatment with ovalbumin but not the major T cell epitope ovalbumin 323–339 generates interleukin-10 secreting T cells and results in the induction of allergen systemic tolerance

BACKGROUND: Nasal administration of major peptide T cell epitopes gives contradictory data on the induction of peripheral tolerance. OBJECTIVE: To compare the prophylactic effect of intranasal treatment (INT) on the development of an allergic response, using either ovalbumin (OVA) or its major T cell epitope OVA 323-339 (OVAp). METHODS: BALB/c mice were treated intranasally with OVA or OVAp and subsequently immunized s.c. with OVA. Anti-OVA-specific antibody, T cell proliferation and cytokine responses were analysed. In an adoptive transfer model using OVAp specific TCR transgenic (Tg) T cells from D011.10 mice, in vivo tracking and characterization of transferred T cells in the cervical, inguinal and bronchial lymph nodes (BLN) and in the spleen were determined by FACS analysis. RESULTS: Prophylactic INT with OVA induced T cell tolerance towards subsequent OVA s.c. immunizations, inhibiting OVA specific T cell proliferation, IgE and IgG1 production, in contrast to INT with OVAp, which was unable to induce tolerance. In vivo analysis of transferred OVA-specific TCR Tg T cells showed that INT with OVA induced a preferential activation of T cells in BLN, as opposed to a broad, systemic activation with OVAp. In vivo, OVAp INT led to faster and more sustained cell division cycles than OVA INT. Ex vivo, tolerance to OVA was associated with the generation of IL-10 secreting CD4(+) T cells in BLN of OVA-treated mice only. CONCLUSION: INT with OVA but not with OVAp led to regional (as opposed to systemic) T cell activation and the induction of IL-10 secreting CD4(+) T cells in BLN, potentially critical steps in the induction of T cell-specific tolerance via the nasal route.     

超顺磁性氧化铁Resovist标记神经干细胞的实验研究

目的研究超顺磁性氧化铁（superparamgnetic iron oxides，SPIOs）标记神经干细胞及其生物学特性．方法：神经干细胞培养、传代和诱导分化；Resovist（一种SPIOs）标记神经干细胞。制备磁标记神经干细胞；利用免疫细胞化学、透射电镜和Prussian blue染色等方法对磁标记神经干细胞生物学特性进行研究。结果：在原代及传代细胞中有Nestin阳性细胞即神经干细胞．血清诱导下，神经干细胞可分化为GFAP、NF200阳性细胞．Resovist与神经干细胞共同孵育后，透射电镜及Prussian blue染色显示胞浆中含有铁颗粒，Resovist也可以随细胞的分裂增殖而传到子代细胞中。随Resovist浓度的增高（5．6μg／ml-11．2μg/ml），Resovist对神经干细胞存活、分化能力的影响无显著性差异（P〉0．05）．当Resovist的浓度大于22．4μg／ml时。Resovist影响其存活和分化（P〈0．05）。结论：本实验利用Resovist作为磁标记探针，对神经干细胞进行成功磁标记，为进一步利用核磁共振（MRI）对神经干细胞活体追踪奠定实验基础。     

Characteristics of antibody responses induced in mice by protein allergens

Whereas many foreign proteins are immunogenic, only a proportion is also allergenic, having the capacity to induce the quality of immune response necessary to support the production of IgE antibody. We have demonstrated previously that intraperitoneal administration to mice of proteins such as ovalbumin (OVA) or the industrial enzyme A. oryzae lipase, which possess significant allergenic potential, stimulates the production of both IgG and IgE antibody. Identical exposure to bovine serum albumin (BSA), a protein with limited potential to cause immediate respiratory or gastrointestinal hypersensitivity reactions, induced IgG responses only. In the current investigations, the quality of immune responses induced following exposure to these proteins via mucosal tissue (intranasal) has been compared with those provoked following administration via a non-mucosal (intraperitoneal) route of exposure. Intranasal or intraperitoneal administration of BSA, OVA or A. oryzae lipase elicited in each case vigorous IgG and IgG1 antibody responses. For all three proteins, at every concentration tested, and via both routes of exposure, IgG1 antibody titres paralleled closely IgG titres. However, the three materials displayed a differential potential to provoke IgE responses and this correlated with their known allergenic potential in humans. Thus, OVA and A. oryzae lipase stimulated strong IgE antibody responses, whereas BSA provoked low titre IgE only at the highest concentration tested (5% administered intraperitoneally). The quality of induced responses was not affected by the route of exposure. It would appear, therefore, that the stimulation of IgG and IgG1 antibody responses is a reflection of protein immunogenicity whereas protein allergenicity is associated with the induction of strong IgE responses.     

抗晶状体蛋白的特异性抗体免疫示踪研究

目的：了解针对晶状体组织的特异性抗体到达眼前节的途经、部位及其对晶状体生理功能的影响。方法：采用荧光标记抗体，观察被动免疫动物眼前节组织中荧光反应的变化，测定晶状体调节力和进行眼前节裂隙灯检查。结果：特异性抗体(IgG)首先到达睫状体部，而后出现在晶状体囊膜、虹膜和角膜内皮上；眼前节抗体含量峰值与裂隙灯观察的房闪、即同时出现；晶状体上皮细胞的损伤与晶状体的调节力下降则出现于转移免疫后2w。结论：针对晶状体组织抗原的特异性抗体可通过体循环先到达睫状体部，然后随房水而作用于晶状体上皮细胞。     

Hydrophobic interactions in Plasmodium falciparum invasion into human erythrocytes

Human glycophorins block in vitro invasion of Plasmodium falciparum merozoites into human erythrocytes. A segment of glycophorin A which appears to be involved in the inhibition, is at, or adjacent to, the membrane-spanning domain of the molecule. To study the role of hydrophobic interactions in the inhibition, a series of proteins were derivatized with lipophilic side groups, and tested for inhibitory activity. Glycophorin A became five times more inhibitory after derivatization with nitrobenzylfurazan groups. Bovine serum albumin was derivatized to different degrees with nitrobenzylfurazan, dinitrobenzyl, trinitrobenzyl, dansyl, disulfonic stilbene, and fluorescein groups. The presence of hydrophobic side groups on the protein rendered it highly inhibitory to invasion, whereas the presence of hydrophilic substitutes such as disulfonic stilbenes did not. Other soluble proteins such as human serum albumin, transferrin, ovalbumin, fetuin and casein derivatized with dinitrobenzyl groups, were also found to block invasion. Inhibition was not a result of toxic effects of the protein derivatives on parasite metabolism or development. A minimum of ten hydrophobic side groups per bovine serum albumin was required in order to elicit appreciable inhibition. The invasion blocking activity was highly correlated with the rate and affinity of binding of the derivatized macromolecules to heptyl-Sepharose. The latter provided a quantitative measure for the capacity of amphiphiles to undergo hydrophobic interactions with insoluble matrices. The results of the present study indicate that hydrophobic interactions may be an essential component in the invasion of P. falciparum merozoites into human erythrocytes.     

Induction of specific anti-actin antibodies and their measurement by ELISA technique.

Using the ELISA technique we have been able to quantify antibodies directed against actin and to follow the kinetics of antibody production. Specific anti-actin antisera have been raised in rabbits by immunization with chemically modified white muscle rabbit actin. Two or three dinitrophenyl groups linked per actin molecule were sufficient to break natural tolerance, while linkage of three phosphorylcholine groups to actin was not.     

包埋前免疫电镜双标技术在神经解剖学研究中的应用

目的　在超微结构水平观察两种神经递质在纤维终末内的共存或一种神经递质与其相应受体之间的关系。　方法　包埋前免疫电镜双重标记技术———酶标法和免疫金 银标记法相结合的方法。　结果　在免疫反应双重标记的纹状体切片上 ,电镜下观察到大量的SP样 (过氧化物酶免疫反应产物 )阳性终末和SP受体 (SPR ,免疫金 银标记颗粒 )样阳性神经元的胞体和树突 ,同时可见部分SP样阳性轴突终末分别与SPR样阳性神经元的胞体或树突形成对称性轴 体或轴 树突触联系。而在三叉神经脊束核尾侧亚核切片上 ,电镜下可观察到大量的两种囊泡膜谷氨酸转运体 ,即DNPI样 (过氧化物酶免疫反应产物 )和VGluT1样 (免疫金 银标记颗粒 )阳性轴突终末 ,同时还观察到DNPI样和VGluT1样双标的轴突终末与阴性树突形成非对称性突触。　结论　包埋前免疫电镜双重标记技术敏感性较高 ,组织的抗原性保存好 ,特别是在神经解剖学研究中 ,用于研究两种神经递质在同一个细胞或终末内的共存或分析神经递质与其相应受体之间的联系中有独到之处。     

Humoral Immunity to Dietary Antigens in Atopic Dermatitis

Enzyme-linked immunosorbent assays (ELISA) employing a biotin-avidin amplification step are described for the quantification of human serum IgG antibodies to the dietary antigens ovalbumin (OA) and beta-lactoglobulin (BLG). The analytical quality of these assays was acceptable. Antibodies were measured in 16 patients with mild or moderate atopic dermatitis (AD), in 31 patients with a history of AD, and in closely matched controls. Levels of serum anti-OA antibodies did not differ in patients and controls, whereas anti-BLG antibodies tended to be higher in patients with mild or moderate AD than in controls (P less than 0.05).