Cultivation of Encapsulated Primary Human B Lymphocytes: A First Step toward a Bioartificial Germinal Center

Polyelectrolyte microcapsules based on sodium cellulose sulfate (SCS) and poly-diallyl-dimethyl-ammonium chloride (PDADMAC) have previously been proposed as a suitable ex vivo microenvironment for the cultivation and differentiation of primary human T lymphocytes. Here, the same system is investigated for the cultivation of human primary B cells derived from adult tonsillar tissue. Proliferation and differentiation into subtypes are followed and compared to suspension cultures of B cells from the same pool performed in parallel. Total cell expansion is somewhat lower in the capsules than in the suspension cultures. More importantly, however, the differentiation of the initially mainly memory B cells into various subtypes, in particular into plasma cell (PC), shows significant differences. Clearly, the microenvironment provided by the microcapsules is beneficial for an accelerated induction of a germinal center-like B cell phenotype and afterward supports the long-term survival of the PC cells. Then, varying the encapsulation conditions (i.e., presence of human serum and dedicated cytokines in the capsule core) provides a tool for finetuning the B cell response. Hence, this methodology is suggested to pave the way toward ex vivo development of human immune organoids.     

Boundedness for the Singular Integral with Variable Kernel and Fractional Differentiation on Weighted Morrey Spaces

Let T be the singular integral operator with variable kernel, T*be the adjoint of T and T~#be the pseudo-adjoint of T. Let T_1T_2 be the product of T_1 and T_2, T_1? T_2 be the pseudo product of T_1 and T_2. In this paper, we establish the boundedness for commutators of these operators and the fractional differentiation operator Dγon the weighted Morrey spaces.     

Quality evaluation and species differentiation of Rhizoma coptidis by using proton nuclear magnetic resonance spectroscopy

Rhizoma coptidis, a broadly used traditional Chinese medicine, derives from the dried rhizomes of Coptis chinensis Franch, Coptis deltoidea C.Y. Cheng et Hsiao and Coptis teeta Wall. Quantitative determination of protoberberine alkaloids in R. coptidis is critical for controlling its quality. In this study, a rapid, simple and accurate quantitative ¹H NMR (qNMR) method was developed for simultaneous determination of berberine, jatrorrhizine, epiberberine, coptisine, palmatine and columbamine in R. coptidis from the three species. Method validation was performed in terms of selectivity, precision, repeatability, stability, accuracy, robustness and linearity. The average recoveries obtained were in the range of 96.9–102.4% for all the six alkaloids. In addition, the qNMR data were analyzed with analysis of variance (ANOVA), hierarchical clustering analysis (HCA) and principal component analysis (PCA), and the results showed that the contents of the active alkaloids have significant difference among the three species. Compared with the conventional HPLC approach, the proposed qNMR method was demonstrated to be a powerful tool for quantifying the six alkaloids due to its unique advantages of high robustness, rapid analysis time and no need of standard compounds for calibration curves preparation. These findings indicate that this method has potential as a reliable method for quality evaluation of herb medicines, especially for protoberberine alkaloid-containing ones.     

基于天然产物的白血病细胞分化机制的化学生物学研究

天然产物由于具有结构多样性和新颖性,具有独特的生理活性和新的作用机制,因此是开展化学生物学研究的重要工具,同时也是创新药物和先导化合物的重要来源.最近,我们研究发现天然活性化合物腺花素能够在体内和体外诱导维甲酸敏感和耐药的急性粒细胞性白血病细胞发生分化,有效延长白血病小鼠生存时间.在此基础上,以腺花素为分子探针,＂垂钓＂其潜在的靶分子,结果发现腺花素特异性靶向过氧化还原酶（Peroxiredoxin）Ⅰ//Ⅱ蛋白,导致H2O2的积聚,H2O2作为第二信使可诱导白血病细胞分化的信号通路.本文对这些工作做了论述和展望.     

Product variety, pricing and differentiation in a supply chain

Manufacturers typically sell consumer products through retailers and the presence of intermediaries has interesting ramifications for their product variety and pricing decisions. Retailers may want higher variety to help reduce price competition but the costs of variety are borne by the manufacturer. The increased variety may increase demand and profits for the manufacturer too but this depends on market-specific factors as well as costs. We explore these interactions through a model wherein a manufacturer sells multiple product variants at a wholesale price to two retailers who in turn compete for consumers. Consumers choose between the retailers based on the price and variety offered by each retailer and the search or transportation cost incurred by the consumer, equivalent to the level of retailer differentiation in our model. Several insights emerge from the analysis. The manufacturer offers the same variety to both retailers and this variety increases with market size and consumer sensitivity to variety. We find that some retailer differentiation benefits the retailers (not the manufacturer) but too much differentiation hurts both the retailers and the manufacturer. If the market is fully covered, then the channel is coordinated even with a simple wholesale pricing contract. If the retailers incur costs to sell the product, the manufacturer surprisingly loses out more than the retailers and in fact absorbs some or all of the retailer costs. Finally, asymmetry between retailers has some unexpected consequences. For example, variety is not impacted by asymmetry in consumer preferences for a retailer and the manufacturer offers the same variety to both retailers.     

Diastereomeric differentiation of peptides with CuII and FeII complexation in an ion trap mass spectrometer

Complexation by transition metal ions (CuII and FeII) was successfully used to differentiate the diastereomeric YAGFL, YDAGFL and Y(D)AGF(D)L pentapeptides by electrospray ionization-ion trap mass spectrometry in the positive ion mode using low-energy collision conditions. This distinction was allowed by the stereochemical effects due to the (D)Leu/(L)Leu and the (D)Ala/(L)Ala residues yielding various steric interactions which direct relative dissociation rate constants of the binary [(M - H) + MeII]+ complexes (Me = Cu or Fe) subjected to low-energy, collision-induced dissociation processes. The interpretation of the collision-induced dissociation spectra obtained from the diastereomeric cationized peptides allowed the location of the deprotonated site(s), leading to the postulation of ion structures and fragmentation pathways for both the [(M - H) + CuII]+ and [(M - H) + FeII]+ complexes, which differed significantly. With CuII, consecutive fragmentations, initiated by the decarboxylation at C-terminus, were favored relative to sequence product ions. On the other hand, with FeII, competitive fragmentations resulting in abundant sequence product ions and significant internal losses were preferred. This could be explained by different localizations of the negative charge, which directs the orientation of both the [(M - H) + CuII]+ and [(M - H) + FeII]+ binary complexes fragmentations. Indeed, the free negative charge of the [(M - H) + CuII]+ ions was mainly located at one oxygen atom: either at the C-terminal carboxylic group or, to a minor extent, at the Tyr phenol group (i.e. zwitterionic forms). On the other hand, the negative charge of the [(M - H) + FeII]+ ions was mainly located at one of the nitrogen atoms of the peptide backbone and coordinated to FeII (i.e. salt non-zwitterionic form).Moreover, this study reveals the particular behavior of CuII reduced to CuI, which promotes radical losses not observed from the peptide-FeII complexes. Finally, this study shows the analytical potentialities of the complexation of transition metal ions with peptides providing structural information complementary to that obtained from low-energy, collision-induced dissociation processes of protonated or deprotonated peptides.     

Variational measures related to local systems and the Ward property of \mathcal{P}-adic path bases

Some properties of absolutely continuous variational measures associated with local systems of sets are established. The classes of functions generating such measures are described. It is shown by constructing an example that there exists a -adic path system that defines a differentiation basis which does not possess Ward property.     

Multipliers between Sobolev spaces and fractional differentiation

We characterize the pointwise multipliers which maps a Sobolev space to a Sobolev space in the case |s|<r<d/2.     

Study of the characteristic fragmentation behavior of hydroquinone glycosides by electrospray ionization tandem mass spectrometry with optimization of collision energy

The fragmentation behavior of hydroquinone glycosides involving one or two sugar groups from Fraxinus sieboldiana and their analogue arbutin was investigated systematically by electrospray ionization tandem mass spectrometry in negative ion mode. The characteristic fragmentation reaction of these compounds was through the homolytic and heterolytic cleavage of the O‐glycosidic bond to produce radical aglycone ion ([Y₀ ? H]^??) and aglycone ion (Y₀^?), respectively. Unambiguous differentiation between the mono‐O‐glycoside isomers which differ in glycosylation position was achieved by comparing the relative abundance of [Y₀ ? H]^?? and Y₀^? ions with the optimized collision energy. In the fragmentation of 1, 4‐di‐O‐glycosides, only the Y₀^? ion was produced when the first glucosyl residue was expelled. However, both the [Y₀ ? H]^?? and Y₀^? ions were present when the second glucosyl residue was eliminated. In addition, an interesting [Y₀‐2H]^? ion was present in the product ion spectra of hydroquinone glycosides with methoxy group(s) substituted at C‐3 or/and C‐5 positions of the benzene ring. The results of this study can facilitate the rapid determination of hydroquinone glycosides in crude plant extracts and also reveal that the systematic investigation and optimization of collision energy play an important role in the differentiation of isomers which have subtle differences in structures. Copyright © 2009 John Wiley & Sons, Ltd.