Fusion intermediates of HIV-1 gp41 as targets for antibody production: design, synthesis, and HR1-HR2 complex purification and characterization of generated antibodies

The objective of this project was to study the interaction between HR1 and HR2, the stability of the complex formed, and to characterize the antibodies produced against monomeric HR1 and HR2 peptides as well as the HR1-HR2 complex. In this work, HR1 was mimicked by peptide N36, and HR2 was mimicked by peptide C34L and its analogues C34M2, C34M3, and C34D. Whereas C34M2 and C34M3 are partially composed of D-amino acids, C34D has same sequence as C34L, but is assembled entirely of D-amino acids. Using CD analysis, SPR assays, and gel filtration chromatography, we demonstrate the physical interaction between N36 and C34L and its analogues C34M2 and C34M3, but not C34D. We show that the HR1-HR2 complex is formed rapidly (<1?min) and remains stable, as demonstrated by its inability, in contrast to each free peptide, to inhibit the formation of syncytia. To generate antibodies with predetermined specificity against the transiently exposed intermediate that corresponds to the six-helix bundle structure, purified preformed HR1-HR2 complex was used, in parallel with monomeric HR1 and HR2 peptides, as immunogens in mice. Although the produced antibodies recognize total HIV-1 envelope glycoproteins in ELISA, they are unable to neutralize HIV-1-mediated fusion at 37?°C. However, if the incubation with these antibodies is carried out at 27?°C, a temperature that allows stabilization of the transient intermediate complex, anti-peptide antibodies are able to bind their corresponding domains in HeLa cells expressing HIV-1 gp41 in co-culture with HeLa CD4-CCR5/CXCR4 during the dynamic mechanism of membrane fusion. In agreement with the latter results, these antibodies, if previously incubated for 2?h at 27?°C, are able to strongly neutralize HIV-1 entry by membrane fusion, as shown by their ability to block the formation of syncytia.     

发动机油非磷抗氧、抗磨、减摩添加剂协同研究

降低发动机油的磷含量,提高燃料经济性,延长使用寿命,已是润滑油升级换代大势所趋。为了降低磷的含量,必须减少二烷基二硫代磷酸锌（ZnDDP）的使用,而二烷基二硫代氨基甲酸锌（ZnDDC）是ZnDDP最理想的替代物。为了提高油品的燃料经济性,需要加入有机钼摩擦改进剂,其中,不含硫磷的钼酸酯添加剂,因其良好的减摩保持性,其应用更为突出。为了满足更苛刻的油品高温性能要求,还必须加入烷基化二苯胺类抗氧剂（ADPA）。因此有必要对非活性钼、ZnDDC和ADPA之间相互作用进行考察。研究表明,在非活性有机钼、ZnDDC、ADPA的三元添加剂体系中,存在着三种相互配合的协同作用：ZnDDC与非活性有机钼的抗磨协同。非活性有机钼与ADPA的抗氧化协同,以及ZnDDC与ADPA的抗氧化协同。利用非活性有机钼、ZnDDC、ADPA的三元非磷协同复合体系（OD0401）,可以大幅度提高油品的抗氧化性能、减摩性能和抗磨性能,这对发展低磷含量的GF-4和GF-5发动机润滑油具有十分积极的意义。利用该协同复合添加剂OD0401,还可以有效地提高低档发动机油的抗氧化和抗磨性能。     

IL-17A in Human Liver: Significant Source of Inflammation and Trigger of Liver Fibrosis Initiation

IL-17A is considered to guide liver inflammation and fibrosis. From twenty-two human liver samples of different fibrosis stages (F0 to F4), IL-17A, IL-22, and TGFβ1 protein expression in liver tissue lysates were analyzed. Ten paired samples of liver tissue (F0–F1 stage) and blood from the same patient were used to analyze intrahepatic and blood T-lymphoid IL-17A⁺ cells by flow cytometry. The analyses have been performed regardless of pathology, considering the stage of fibrosis. Human liver tissue was used for the primary human liver slice cultures, followed by subsequent cytokine stimulation and fibrotic markers’ analysis by ELISA. IL-17A production in human liver tissue was significantly higher in the early fibrotic stage compared with the advanced stage. Th17 T cells and, to a lesser extent, MAIT cells were the main sources of IL-17A in both compartments, the liver and the blood. Moreover, the presence of liver Th17IL-17A⁺INFγ⁺ cells was detected in the liver. IL-17A stimulation of human liver slice culture increased the expression of profibrotic and pro-inflammatory markers. IL-17A, secreted by Th17 and MAIT cells in the liver, triggered fibrosis by inducing the expression of IL-6 and profibrotic markers and could be a target for antifibrotic treatment. Further amplitude studies are needed to confirm the current results.     

Pentoxifylline does not prevent the cytokine-induced first dose reaction following OKT3--a randomized, double-blind placebo-controlled study

The use of OKT3 as an immunosuppressive agent is accompanied by increased cytokine production and constellation of side effects collectively termed cytokine release syndrome (CRS). Pentoxifylline (PTF) inhibits synthesis of some cytokines, and has been shown to attenuate CRS when administered before OKT3. In this double-blinded, placebo-controlled study, 46 renal allograft recipients were randomized to receive either PTF (800 mg q 8 hr for at least 24 h) p.o. or placebo, along with methylprednisolone (7 mg/kg), diphenhydramine, and acetaminophen, prior to beginning OKT3 as therapy for acute rejection. Patients were observed, and symptoms scored semiquantitatively. Despite the presence of therapeutic PTF levels (721 +/- 726 ng/ml), the frequency and severity of side effects (fever, chills, headache, neurocortical symptoms, dyspnea, nausea, vomiting, diarrhea) did not differ between treatment groups. Likewise PTF did not affect renal function or immunologic response to OKT3, with similar graft and patient survival in both groups. Plasma levels of TNF alpha, IFN gamma, IL-6, and IL-8 increased as predicted following OKT3 administration, without significant differences between PTF and placebo groups. In this controlled, multicenter trial, pretreatment with oral PTF was ineffective in attenuating OKT3-related CRS in renal allograft recipients.     

The Influence of Inverter Feeding on the Apparent Stray Inductance of Asynchronous Machines

The stray inductance is an important parameter for the design of inverters feeding asynchronous machines. Measurements are proposed which are relevant for determining the apparent stray inductance of an inverter-fed asynchronous machine. These measurements show that the apparent stray inductance is considerably smaller than the one obtained with classical sinusoidal methods. This amounts to smaller commutating capacitors in current source inverter (CSI) motor drives. A theoretical explanation for this phenomenon is presented and confirmed by calculation.     

Relation of patient pretreatment characteristics to the therapeutic alliance in diverse psychotherapies.

The prediction of the therapeutic alliance from patient pretreatment characteristics was investigated with a sample of elderly depressed outpatients treated in behavioral, cognitive, and brief dynamic psychotherapy (N?=?60). For the sample as a whole, a higher degree of patient defensiveness was related to a lower patient contribution to the alliance as reflected in patient commitment and working capacity. Also, the availability of environmental support was positively associated with greater patient commitment across treatment conditions. The association of patient pretreatment characteristics with alliance was similar across behavioral and cognitive therapy and less similar across brief dynamic and behavioral or cognitive therapy. The nature of the therapeutic alliance in diverse treatment modalities is discussed, and implications for selection criteria and technical strategies for engaging the difficult patient are explored. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of residual isopropanol and propylene glycol in soft drinks by glass capillary gas chromatography

European Food Research and Technology - A method is described for the quantitative determination of the residual solvents isopropanol and propylene glycol in soft drinks. The proposed methods are...     

Body size and feeding specificity: macrolepidoptera in Britain

Within a geographic assemblage, large-bodied species of macrolepidopteran moths tend, on average, to be less host-specific than small-bodied. Five possible explanations for this pattern are identified, based respectively on (i) phylogenetic relationships between species, (ii) latitudinal gradients in body size and feeding specificity, (iii) the relationship between range size and body size, (iv) larger body size as a buffer from environmental variation, and (v) the relationship between endophagous host associations and small body size. These mechanisms are tested using data for British macrolepidoptera and also evaluated using evidence from the literature at large. Although some of their assumptions are found to be justified, there is no significant support for any single mechanism. This lack of evidence for previously proposed mechanisms is discussed in the light of a recently proposed alternative explanation which combines theories of host quality and host defence mechanisms.Copyright 1998 The Linnean Society of London     

润滑油抗氧剂协同作用研究

对润滑油的氧化机理做了简要阐述,并根据不同的抗氧作用机理,将抗氧剂分为三类:自由基清除剂(如酚类和胺类抗氧剂)、氢过氧化物分解剂(如氨基甲酸酯)和抗氧协合剂(如不含硫磷的钼酸酯).利用加压差示扫描量热法(PDSC)对不同类型抗氧剂以及它们之间的协同作用进行了考察.研究表明,作为氢过氧化物分解剂,改进的无灰氨基甲酸酯具有比胺类、酚类抗氧剂更好的性能,这显示了氢过氧化物分解型抗氧剂巨大的应用潜力.研究还表明,具有相同抗氧机理的不同抗氧剂,如酚类和胺类抗氧剂,具有协同作用;不同作用机理的两抗氧剂之间,如自由基清除剂和氢过氧化物分解剂,具有更好的抗氧化协同效果,其中,无灰氨基甲酸酯与烷基化二苯胺抗氧剂具有最佳的抗氧协同效能,可成为高温无灰抗氧剂应用的一个很好选择;不同抗氧机理的三种抗氧剂复合,如烷基化二苯胺,氨基甲酸锌和有机钼酸酯组成的三元复合抗氧剂,具有更为优秀的抗氧化性能.通过不同机理抗氧剂之间的协同,不仅可以获得优秀的抗氧化性能,还可获得附加的极压、抗磨和减摩性能,而且有的减摩、抗磨性能还非常突出,如烷基化二苯胺、氨基甲酸锌和有机钼酸酯组成的三元复合添加剂体系.