HBeAg(+)或抗-Hbe(+)病人血清中HBV标志检测临床意义

近年来,由于乙肝病毒(HBV)分子生物学研究取得很大进展,为HBV标志物检测提供了灵敏的方法,从而使临床评价HBV标志物的工作得到广泛开展[1]。本文报告90份HBeAg( )和56份抗HBe( )病人血清HBV标志物检测结果,探讨其临床意义。临床资料1检测血清本文检测血清标本均为我院住院病人,HBeAg( )病人90例,其中急性乙型肝炎(急肝)13例,慢性活动性肝炎(慢迁肝)39例,慢性迁延性肝炎(慢迁肝)31例,肝硬化7例。抗Hbe( )病人56例,其中急肝5例,慢活肝13例,慢迁肝29例,肝硬化9例。肝炎诊断依据1990年第六次全国肝炎会议修订标准,肝硬化诊断依据内科学…     

天然产物(+)-Balasubramide的合成

以肉桂醛为起始原料,经一锅法不对称环氧化、酯胺缩合和分子内环合三步反应,不对称合成天然产物(+)-balasubramide,总收率为44%,ee值为99%。其结构经1H NMR、13C NMR、HR-MS和IR确证。本化学合成方法简单,产率较高,为进一步研究该天然产物的生物活性及构效关系奠定一定基础。     

Cyclohexene epoxides, (+)-pandoxide, (+)β-senepoxide and (−)-pipoxide,from Uvaria pandensis

The new cyclohexene epoxide (+)-pandoxide along with (+)-β-senepoxide and (−)-pipoxide were isolated from the stembark, roots and leaves of the new Uvaria species U. pandensis. Their structures and stereochemical configurations were determined by spectroscopic methods. The pipoxide has an absolute configuration opposite to the one previously isolated from Uvaria species. The absolute stereochemical configuration of (+)-β-senepoxide was assigned unambiguously by an X-ray diffraction analysis.     

Role of the frequency of blood CD4(+) CXCR5(+) CCR6(+) T cells in autoimmunity in patients with Sjögren's syndrome

The blood CD4⁺ CXCR5⁺ T cells, known as “circulating” Tfh, have been shown to efficiently induce naïve B cells to produce immunoglobulin. They play an important role in certain autoimmune diseases. In the present study, we show for the first time that the frequency of CD4⁺ CXCR5⁺ T cells is increased in pSS patients and positively correlated with autoantibodies in the blood. The concentration of Th17-like subsets (CD4⁺ CXCR5⁺ CCR6⁺) in pSS patients was found to be significantly higher than in healthy controls. Functional assays showed that activated Th17-like subtypes in the blood display the key features of Tfh cells, including invariably coexpressed PD-1, ICOS, CD40L and IL-21. Th17 subsets were found to highly express Bcl-6 protein and Th1 and Th2 were not. Bcl-6 is believed to be a master transforming factor for Tfh cell differentiation and facilitate B cell proliferation and somatic hypermutation within the germinal center. These data indicate that Th17 subsets of CD4⁺ CXCR5⁺ T cells in the blood may participate in the antibody-related immune responses and that high frequency of CD4⁺ CXCR5⁺ CCR6⁺ Tfh cells in blood may be suitable biomarkers for the evaluation of the active immune stage of pSS patients. It might provide insights into the pathogenesis and perhaps help researchers identify novel therapeutic targets for pSS.     

E2→E1 transition and Rb(+) release induced by Na(+) in the Na(+)/K(+)-ATPase. Vanadate as a tool to investigate the interaction between Rb(+) and E2

This work presents a detailed kinetic study that shows the coupling between the E2→E1 transition and Rb(+) deocclusion stimulated by Na(+) in pig-kidney purified Na,K-ATPase. Using rapid mixing techniques, we measured in parallel experiments the decrease in concentration of occluded Rb(+) and the increase in eosin fluorescence (the formation of E1) as a function of time. The E2→E1 transition and Rb(+) deocclusion are described by the sum of two exponential functions with equal amplitudes, whose rate coefficients decreased with increasing [Rb(+)]. The rate coefficient values of the E2→E1 transition were very similar to those of Rb(+)-deocclusion, indicating that both processes are simultaneous. Our results suggest that, when ATP is absent, the mechanism of Na(+)-stimulated Rb(+) deocclusion would require the release of at least one Rb(+) ion through the extracellular access prior to the E2→E1 transition. Using vanadate to stabilize E2, we measured occluded Rb(+) in equilibrium conditions. Results show that, while Mg(2+) decreases the affinity for Rb(+), addition of vanadate offsets this effect, increasing the affinity for Rb(+). In transient experiments, we investigated the exchange of Rb(+) between the E2-vanadate complex and the medium. Results show that, in the absence of ATP, vanadate prevents the E2→E1 transition caused by Na(+) without significantly affecting the rate of Rb(+) deocclusion. On the other hand, we found the first evidence of a very low rate of Rb(+) occlusion in the enzyme-vanadate complex, suggesting that this complex would require a change to an open conformation in order to bind and occlude Rb(+).     

A bioprocess for the production of high concentrations of R-(+)-α-terpineol from R-(+)-limonene

A bioprocess with a high conversion rate of limonene to α-terpineol was described. The enzyme hydratase involved in this process was found as being cofactor independent, non-inducible and able to perform the transformation of both R-(+) and S-(−)-limonene. The system used consisted of a biphasic medium in which the aqueous phase contained a concentrated resting cells of Sphingobium sp. and the organic phase was sunflower oil. After 30 h at 30 °C ca. 25 g of R-(+)-α-terpineol per liter of organic phase were obtained from R-(+)-limonene in Erlenmeyer flasks. Performance of the bioconversion in a bioreactor increased the production rate with no changes in yield and maximal R-(+)-α-terpineol concentration, which demonstrated that experiments in flasks were limited by liquid–liquid transport phenomena. A mathematical model able to explain the fact that the reaction always stopped before the precursor became exhausted has also been proposed and validated. Finally, the process reported was the most promising alternative for the biotechnological production of natural R-(+)-α-terpineol published so far and up to ca. 130 g L⁻¹ metabolite could finally be obtained.     

SA-4-1BBL Costimulation Inhibits Conversion of Conventional CD4(+) T Cells into CD4(+)FoxP3(+) T Regulatory Cells by Production of IFN-γ

Tumors convert conventional CD4⁺ T cells into induced CD4⁺CD25⁺FoxP3⁺ T regulatory (iTreg) cells that serve as an effective means of immune evasion. Therefore, the blockade of conventional CD4⁺ T cell conversion into iTreg cells represents an attractive target for improving the efficacy of various immunotherapeutic approaches. Using a novel form of 4-1BBL molecule, SA-4-1BBL, we previously demonstrated that costimulation via 4-1BB receptor renders both CD4⁺and CD8⁺ T effector (Teff) cells refractory to inhibition by Treg cells and increased intratumoral Teff/Treg cell ratio that correlated with therapeutic efficacy in various preclinical tumor models. Building on these studies, we herein show for the first time, to our knowledge, that signaling through 4-1BB inhibits antigen- and TGF-β-driven conversion of naïve CD4⁺FoxP3⁻ T cells into iTreg cells via stimulation of IFN-γ production by CD4⁺FoxP3⁻ T cells. Importantly, treatment with SA-4-1BBL blocked the conversion of CD4⁺FoxP3⁻ T cells into Treg cells by EG.7 tumors. Taken together with our previous studies, these results show that 4-1BB signaling negatively modulate Treg cells by two distinct mechanisms: i) inhibiting the conversion of CD4⁺FoxP3⁻ T cells into iTreg cells and ii) endowing Teff cells refractory to inhibition by Treg cells. Given the dominant role of Treg cells in tumor immune evasion mechanisms, 4-1BB signaling represents an attractive target for favorably tipping the Teff:Treg balance toward Teff cells with important implications for cancer immunotherapy.     

Enzymatic activity of cell-free extracts from Burkholderia oxyphila OX-01 bio-converts (+)-catechin and (−)-epicatechin to (+)-taxifolin

This study characterized the enzymatic ability of a cell-free extract from an acidophilic (+)-catechin degrader Burkholderia oxyphila (OX-01). The crude OX-01 extracts were able to transform (+)-catechin and (?)-epicatechin into (+)-taxifolin via a leucocyanidin intermediate in a two-step oxidation. Enzymatic oxidation at the C-4 position was carried out anaerobically using H₂O as an oxygen donor. The C-4 oxidation occurred only in the presence of the 2R-catechin stereoisomer, with the C-3 stereoisomer not affecting the reaction. These results suggest that the OX-01 may have evolved to target both (+)-catechin and (?)-epicatechin, which are major structural units in plants.     

牛NAD(+)异柠檬酸脱氢酶生物信息学分析

异柠檬酸脱氢酶(IDH)是三羧酸循环中的关键酶。为了进一步探索IDH的结构与功能,利用生物信息学方法对牛NAD(+)IDH进行分析。结果表明,该蛋白为亲水性蛋白,呈碱性,无跨膜区,在β亚基N端存在长度为16个氨基酸的信号肽,亚细胞定位在线粒体。二级结构预测结果显示该蛋白的三个亚基均以α螺旋为主,并且其上的螺旋和折叠均紧密有序排列,这有助于形成特定的结构域并发挥特定的生物学功能。对α和γ两个亚基采用同源建模法预测其三级结构模型,β亚基采用折叠识别法预测其三级结构模型,预测结果质量评估均较好。此外,分析了不同亚基的表面电荷分布,并预测了最可能的异柠檬酸和ADP的结合位点。通过生物信息学方法进行合理预测,为进一步研究IDH家族尤其是哺乳动物NAD(+)IDH提供了重要理论依据。     

Expansion of CD14(+)CD16(+) monocytes producing TNF-α in complication-free diabetes type 1 juvenile onset patients

We concentrated on the complication-free phase of juvenile onset type 1 diabetes mellitus (T1DM) searching for associations between concentration of inflammatory factors TNF-α, CRP and VEGF and two monocyte subsets the CD14(++)CD16(-) and CD14(+)CD16(+). We analysed a randomly selected group of 150 patients without complications (disease duration 2.74±2.51years) at the start of the project and 5years later. They were compared with 24 patients with retinopathy (6.53±3.39years of disease) and 30 healthy volunteers. Our results indicate that in the complication-free period the concentration of TNF-α significantly increased and continued to increase after retinopathy was established. After 5years the percentage and absolute number of CD14(+)CD16(+) monocytes doubled in complication-free patients. Our study indicates that the size of CD14(+)CD16(+) monocyte subset may be used alternatively to CRP values as an indicator of inflammation grade. Our results imply the necessity of trials using anti-TNF-α therapy in the complication-free phase of the disease.     

CD137^(+)T细胞效应功能研究进展

CD137^(+)(又称4-1BB、TNFRSF9)T细胞亚群是一类抗原特异性活化的效应细胞。CD137^(+)T细胞产生细胞毒效应因子以及在抗原刺激后进行增殖的能力较强,使其在多种疾病中发挥免疫调节作用,其中CD137^(+)调节性T细胞分泌的分泌型CD137具有重要的免疫抑制作用。因此,全面了解CD137^(+)T细胞在疾病中的作用,对开发有效的疾病免疫防治策略至关重要。本文通过介绍CD137相关信号对T细胞尤其是CD8^(+)T细胞功能的调控机制、CD137^(+)T细胞的特征和效应功能、CD137^(+)T细胞在多种疾病进展中的免疫调控作用,为靶向CD137^(+)T细胞的免疫治疗提供参考。     

Biotransformation of (−)-epicatechin, (+)-epicatechin, (−)-catechin,and (+)-catechin by intestinal bacteria involved in isoflavone metabolism

Isoflavone-metabolizing bacteria, Adlercreutzia equolifaciens, Asaccharobacter celatus, Slackia equolifaciens, and Slackia isoflavoniconvertens catalyzed C-ring cleavage of (–)-epicatechin and (+)-catechin, (+)-epicatechin, and (–)-catechin in varying degrees. The cleaving abilities of (–)-epicatechin and (+)-catechin were enhanced by hydrogen, except (+)-catechin cleavage by S. equolifaciens, which was not accelerated. (?)-Catechin cleavage by Ad. equolifaciens was remarkably accelerated by hydrogen.     

天然产物(+)-Balasubramide的合成北大核心CSCD

以肉桂醛为起始原料,经一锅法不对称环氧化、酯胺缩合和分子内环合三步反应,不对称合成天然产物(+)-balasubramide,总收率为44%,ee值为>99%。其结构经1H NMR、13C NMR、HR-MS和IR确证。本化学合成方法简单,产率较高,为进一步研究该天然产物的生物活性及构效关系奠定一定基础。     

棒状杆菌固定化细胞生产L(+)-酒石酸

以卡拉胶为载体,固定化棒状杆菌(Corynebacterium sp.)JZ1菌株细胞,再经活化处理,顺式环氧琥珀酸水解酶(ESH)酶活力总回收率在100%以上。摇瓶反应10批,酶活力没有明显降低。1500L酶柱中连续运行90d,酶稳定性很好。固定化后酶反应的最适温度(45℃)和最适pH(90)没有改变,而热稳定性、pH稳定性增强     

L(+)-酒石酸发酵法生产工艺改进的研究

虽然具有广泛用途的Ｌ( ) 酒石酸的生产方法有 4种[1 ] ,但目前研究最多 ,最具工业生产前景的方法 ,是应用化学合成的前体为底物 ,发酵生产Ｌ( ) 酒石酸的方法。该法中的微生物发酵转化适宜在弱碱性的条件下进行 ,通常都是把顺式环氧琥珀酸制备成相应的二钠盐来作为前体 ,再进行微生物转化生成Ｌ( ) 酒石酸。张建国[2 ] 、黄腾华等人[3 ] 在实验室按以上路线生产Ｌ( ) 酒石酸 ;孙志浩等人[4] 以明胶为载体固定化微生物细胞生产Ｌ( ) 酒石酸 ;张建国等人[5 ]在他们自己工作的基础上进一步探讨了细胞固定化的方法 ,找到了一种…     

商陆皂苷甲基于CD19^(+)IL-35^(+)Breg细胞对MRL/lpr小鼠肾炎的影响

[目的]探讨商陆皂苷甲对MRL/lpr小鼠肾炎的影响和作用机制。[方法] 24只16周龄MRL/lprx小鼠随机分为对照组、商陆皂苷甲组、商陆皂苷甲+IL-12p35抗体组,每组8只。实验组分别注射相应药物,1次/d,对照组给予等量生理盐水,持续4 w。给药结束后,检测血肌酐、尿蛋白/肌酐值水平;HE染色、Masson+PASM染色观察肾脏病理表现;计算AI指数、脾脏指数;检测CD19^(+)IL-35^(+)Breg细胞含量,IL-17、IL-35水平;分析CD19^(+)IL-35^(+)Breg细胞与IL-17、IL-35的相关性。[结果]与对照组比较,实验组尿蛋白/肌酐值、血肌酐浓度含量降低(P<0.05),其中商陆皂苷甲组尿蛋白/肌酐值、血肌酐浓度含量低于商陆皂苷甲+IL-12p35抗体组(P<0.05);实验组肾脏损伤情况优于对照组,其中商陆皂苷甲组优于商陆皂苷甲+IL-12p35抗体组;实验组脾脏指数、AI评分低于对照组(P<0.05),其中商陆皂苷甲组脾脏指数、AI评分低于商陆皂苷甲+IL-12p35抗体组(P<0.05);实验组IL-17较对照组下降,CD19^(+)IL-35^(+)Breg细胞含量、IL-35值较对照组升高(P<0.05),其中商陆皂苷甲组IL-17值低于商陆皂苷甲+IL-12p35抗体组(P<0.05),CD19^(+)IL-35^(+)Breg细胞含量、IL-35值高于商陆皂苷甲+IL-12p35抗体组(P<0.05);IL-35上调、IL-17下调与CD19^(+)IL-35^(+)Breg细胞变化相关(P<0.05)。[结论]商陆皂苷甲降低MRL/lprx小鼠肾脏炎症反应,其机制可能与促进CD19^(+)IL-35^(+)Breg细胞增殖有关。     

A 133Cs nuclear magnetic resonance study of endothelial Na(+)-K(+)-ATPase activity: can actin regulate its activity?

Using (133)Cs+ NMR, we developed a technique to repetitively measure, in vivo, Na(+)-K(+)-ATPase activity in endothelial cells. The measurements were made without the use of an exogenous shift reagent, because of the large chemical shift of 1.36 +/- 0.13 ppm between intra- and extracellular Cs+. Intracellularly we obtained a spin lattice relaxation time (T1) of 2.0 +/- 0.3 s, and extracellular T1 was 7.9 +/- 0.4 s. Na(+)-K+ pump activity in endothelial cells was determined at 12 +/- 3 nmol Cs+ x min(-1) x (mg Prot)[-1] under control conditions. When intracellular ATP was depleted by the addition of 5 mM 2-deoxy-D-glucose (DOG) and NaCN to about 5% of control, the pump rate decreased by 33%. After 80 min of perfusion with 5 mM DOG and NaCN, reperfusion with control medium rapidly reestablished the endothelial membrane Cs+ gradient. Using (133)Cs+ NMR as a convenient tool, we further addressed the proposed role of actin as a regulator of Na(+)-K+ pump activity in intact cells. Two models of actin rearrangement were tested. DOG caused a rearrangement of F-actin and an increase in G-actin, with a simultaneous decrease in ATP concentration. Cytochalasin D, however, caused an F-actin rearrangement different from that observed for DOG and an increase in G-actin, and cellular ATP levels remained unchanged. In both models, the Na(+)-K(+)-pump activity remained unchanged, as measured with (133)Cs NMR. Our results demonstrate that (133)Cs NMR can be used to repetitively measure Na(+)-K(+)-ATPase activity in endothelial cells. No evidence for a regulatory role of actin on Na(+)-K(+)-ATPase was found.     

Potential α-glucosidase inhibitors from thermal transformation of (+)-catechin

Thermal transformation of the (+)-catechin (1) with heating processing afforded a new oxidation product, gambiriin D (2), along with catechin [6′–8]-catechin (3), and (+)-epicatechin (4). The structure of a new catechin dimer with C–C linkage was determined on the basis of spectroscopic data interpretation. The catechin dimers 2 and 3 exhibited significantly improved inhibitory activities against α-glucosidase, with IC₅₀ values of 0.16 ± 0.2 and 0.14 ± 0.2 μM, respectively, when compared to parent (+)-catechin. Kinetic analysis showed that the two effective compounds 2 and 3 have noncompetitive modes of action.     

微波诱变L(+)-乳酸高产菌株的选育

为了获得L-乳酸高产菌株,对干酪乳杆菌（Lactobacillus casei）CICC6028进行微波诱变。通过考察微波辐照功率和时间等因素对诱变结果的影响,得出最佳诱变方法是：间歇诱变方法,微波输出功率480W,辐照时间40s。最后得到一株遗传稳定的L（＋）-乳酸高产菌株MW-46,产酸量最高为98．12g／L,与出发菌相比,提高了54．14％。