Determination of Relative Response Factors of Cefazolin Impurities by Quantitative NMR

The relative response factors (RRFs) of ten cefazolin impurities were determined by quantitative nuclear magnetic resonance (qNMR) and high-performance liquid chromatography (HPLC) equipped with an ultraviolet (UV) detector. The purities of these ten cefazolin impurities were successfully measured by qNMR for the purpose of RRFs determination by HPLC. The RRF values and their uncertainties determined by the two approaches are comparable. While the qNMR approach is effective and makes it easier to determine the RRFs for impurities, it also has the advantage of allowing the universal detection of protons without the limitations of common mass detectors. The use of qNMR provides a reliable and universal method for the RRF determination of impurities.     

A new antifibrotic target of Ac-SDKP: inhibition of myofibroblast differentiation in rat lung with silicosis

Background

Myofibroblast differentiation, characterized by α-smooth muscle actin (α-SMA) expression, is a key process in organ fibrosis, and is induced by TGF-β. Here we examined whether an anti-fibrotic agent, N-acetyl-seryl-aspartyl-lysylproline (Ac-SDKP), can regulate induction of TGF-β signaling and myofibroblast differentiation as a potential key component of its anti-fibrotic mechanism in vivo and in vitro.

Methodology/Principal Findings

Rat pulmonary fibroblasts were cultured in vitro and divided to 4 groups 1) control; 2) TGF-β1; 3) TGF-β1+ {"type":"entrez-nucleotide","attrs":{"text":"LY364947","term_id":"1257906561","term_text":"LY364947"}}LY364947; 4) TGF-β1+Ac-SDKP. For in vivo studies, six groups of animals were utilized 1) control 4w; 2) silicotic 4w; 3) control 8w; 4) silicotic 8w; 5) Ac-SDKP post-treatment; 6)Ac-SDKP pre-treatment. SiO₂ powders were douched in the trachea of rat to make the silicotic model. Myofibroblast differentiation was measured by examining expression of α-SMA, as well as expression of serum response factor (SRF), a key regulator of myofibroblast differentiation. The expressions of collagen, TGF-β1 and RAS signaling were also assessed. The results revealed that TGF-β1 strongly induced myofibroblast differentiation and collagen synthesis in vitro, and that pre-treatment with Ac-SDKP markedly attenuated myofibroblast activation, as well as induction of TGF-β1 and its receptor. Similar results were observed in vivo in the pathologically relevant rat model of silicosis. Ac-SDKP treatment in vivo strongly attenuated 1) silicosis-induced increased expressions of TGF-β1 and RAS signaling, 2) myofibroblast differentiation as indicated by a robust decrease of SRF and α-SMA-positive myofibroblast localization in siliconic nodules in the lung, 3) collagen deposition.

Conclusion/Significance

The results of the present study suggest a novel mechanism of action for Ac-SDKP’s beneficial effect in silicosis, which involves attenuation of TGF-β1 and its receptors, SRF and Ang II type 1 receptor (AT₁) expression, collagen deposition and myofibroblast differentiation. The results further suggest that therapies targeting myofibroblast differentiation may have therapeutic efficacy in treatment of silicosis of the lung.     

260株气单胞菌的表型特性与毒素原性研究

本文对山东省9市（地）临床和外环境等6种标本中检出的260株气单胞菌进行了表型特性研究。结果表明：山东省以温和气单胞菌为主（52.69％）,嗜水气单胞菌（23．4％）、豚鼠气单胞菌（23.08％）次之。自淡水鱼中检出维隆气单胞菌和易损气单胞菌各1株。随机抽取163株应用溶血试验、CHO细胞测毒素试验、兔肠结扎及CT基因探针杂交试验进行毒素原性研究,温和、嗜水及豚鼠气单胞菌均可产生溶血素、肠毒素,某些菌株的肠毒素具有与严乱肠毒素呈交叉反应因子（CTCE）。     

黄河三角洲丹顶鹤秋冬季生境选择机制

影响水禽生境选择要素可分为水、食物、隐蔽物和干扰4类,对其划分等级标准,确定采样点的生境类型。在研究区内分秋冬两季调查丹顶鹤(迁徙期和越冬期)生境选择机制的差异;在不同时期按区域的特点和丹顶鹤的生活习性分别选择样点;经过实地野外调查后再利用方差分析和频数对丹顶鹤生境选择机制进行研究。结果表明,迁徙期影响丹顶鹤生境选择的主要因子是干扰,最适生境为远离人类干扰、有浅水域分布的、植被覆盖率较低的地区;越冬期影响丹顶鹤生境选择的主要因子是食物,最喜欢选择人类干扰相对较小的、有水域分布的、动物性食物占主导地位的植被覆盖率较低的地区栖息。     

IL-2 simultaneously expands Foxp3+ T regulatory and T effector cells and confers resistance to severe tuberculosis (TB): implicative Treg-T effector cooperation in immunity to TB

The possibility that simultaneous expansion of T regulatory cells (Treg) and T effector cells early postinfection can confer some immunological benefits has not been studied. In this study, we tested the hypothesis that early, simultaneous cytokine expansion of Treg and T effector cells in a tissue infection site can allow these T cell populations to act in concert to control tissue inflammation/damage while containing infection. IL-2 treatments early after Mycobacterium tuberculosis infection of macaques induced simultaneous expansion of CD4(+)CD25(+)Foxp3(+) Treg, CD8(+)CD25(+)Foxp3(+) T cells, and CD4(+) T effector/CD8(+) T effector/Vγ2Vδ2 T effector populations producing anti-M. tuberculosis cytokines IFN-γ and perforin, and conferred resistance to severe TB inflammation and lesions. IL-2-expanded Foxp3(+) Treg readily accumulated in pulmonary compartment, but despite this, rapid pulmonary trafficking/accumulation of IL-2-activated T effector populations still occurred. Such simultaneous recruitments of IL-2-expanded Treg and T effector populations to pulmonary compartment during M. tuberculosis infection correlated with IL-2-induced resistance to TB lesions without causing Treg-associated increases in M. tuberculosis burdens. In vivo depletion of IL-2-expanded CD4(+)Foxp3(+) Treg and CD4(+) T effectors during IL-2 treatment of M. tuberculosis-infected macaques significantly reduced IL-2-induced resistance to TB lesions, suggesting that IL-2-expanded CD4(+) T effector cells and Treg contributed to anti-TB immunity. Thus, IL-2 can simultaneously activate and expand T effector cells and Foxp3(+) Treg populations and confer resistance to severe TB without enhancing M. tuberculosis infection.     

An update: Epstein-Barr virus and immune evasion <Emphasis Type="Italic">via</Emphasis> microRNA regulation

Epstein-Barr virus (EBV) is an oncogenic virus that ubiquitously establishes life-long persistence in humans. To ensure its survival and maintain its B cell transformation function, EBV has developed powerful strategies to evade host immune responses. Emerging evidence has shown that microRNAs (miRNAs) are powerful regulators of the maintenance of cellular homeostasis. In this review, we summarize current progress on how EBV utilizes miRNAs for immune evasion. EBV encodes miRNAs targeting both viral and host genes involved in the immune response. The miRNAs are found in two gene clusters, and recent studies have demonstrated that lack of these clusters increases the CD4⁺ and CD8⁺ T cell response of infected cells. These reports strongly indicate that EBV miRNAs are critical for immune evasion. In addition, EBV is able to dysregulate the expression of a variety of host miRNAs, which influence multiple immune-related molecules and signaling pathways. The transport via exosomes of EBV-regulated miRNAs and viral proteins contributes to the construction and modification of the inflammatory tumor microenvironment. During EBV immune evasion, viral proteins, immune cells, chemokines, pro-inflammatory cytokines, and pro-apoptosis molecules are involved. Our increasing knowledge of the role of miRNAs in immune evasion will improve the understanding of EBV persistence and help to develop new treatments for EBV-associated cancers and other diseases.

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Bestatin, an inhibitor of aminopeptidases, provides a chemical genetics approach to dissect jasmonate signaling in Arabidopsis

Bestatin, a potent inhibitor of some aminopeptidases, was shown previously to be a powerful inducer of wound-response genes in tomato (Lycopersicon esculentum). Here, we present several lines of evidence showing that bestatin specifically activates jasmonic acid (JA) signaling in plants. First, bestatin specifically activates the expression of JA-inducible genes in tomato and Arabidopsis (Arabidopsis thaliana). Second, the induction of JA-responsive genes by bestatin requires the COI1-dependent JA-signaling pathway, but does not depend strictly on JA biosynthesis. Third, microarray analysis using Arabidopsis whole-genome chip demonstrates that the gene expression profile of bestatin-treated plants is similar to that of JA-treated plants. Fourth, bestatin promotes a series of JA-related developmental phenotypes. Taken together, the unique action mode of bestatin in regulating JA-signaled processes leads us to the hypothesis that bestatin exerts its effects through the modulation of some key regulators in JA signaling. We have employed bestatin as an experimental tool to dissect JA signaling through a chemical genetic screening, which yielded a collection of Arabidopsis bestatin-resistant (ber) mutants that are insensitive to the inhibitory effects of bestatin on root elongation. Further characterization efforts demonstrate that some ber mutants are defective in various JA-induced responses, which allowed us to classify the ber mutants into three phenotypic groups: JA-insensitive ber mutants, JA-hypersensitive ber mutants, and mutants insensitive to bestatin but showing normal response to JA. Genetic and phenotypic analyses of the ber mutants with altered JA responses indicate that we have identified several novel loci involved in JA signaling.     

Optimized cultivation of highly-efficient degradation bacterial strains and their degradation ability towards pyrene

Two bacterial strains, Py1 and Py4, have been tamed and isolated through long cultivation with polycyclic aromatic hydrocarbon—pyrene as the single carbon source. It has been proven that they are both highly-efficient pyrene degrading bacteria and both Bacillus sp.. The pyrene degradation ability of separated Py1, Py4 and the consortium of equal Py1 and Py4 was studied in this project. It is shown that pyrene degradation rates were 88% in 10hr by Py1, 84% in 14hr by Py4, and 88% in 8hr by the consortium. It was also determined that the best degradation temperatures were 37°C and pH 7.0 respectively. The influence of different nutrient substrates added in the degradation experiments was also studied. It was shown that sodium salicylate, sodium acetate and yeast extract had obvious simulative effect, but glucose had no obvious effect. __________ Translated from Acta Scientiarum Naturalium Universitatis Nankaiensis (Natural Science Edition) 2006, 39: 71–74 [译自: 南开大学学报 (自然科学版)]     

Nephrin expression is increased in anti-Thy1.1-induced glomerulonephritis in rats

Nephrin is an important constituent of the glomerular filtration barrier and alteration of its expression is associated with severe proteinuria. In this study we show that injection of an anti-Thy1.1 antibody in rats not only induces a mesangioproliferative glomerulonephritis associated with increased proteinuria, but also leads to a sustained increase of nephrin mRNA and protein expression in renal glomeruli over a time period of 29 days. In contrast, podocin and CD2AP, two proteins shown to interact with nephrin in the slit diaphragm, are acutely downregulated at days 3-7 and, thereafter, recovered again to normal levels after 29 days. Interestingly, immunofluorescence staining of kidney sections at day 10 of the disease shows a highly heterogeneous pattern, in that some podocytes show complete absence of nephrin, whereas others show highly accumulated staining for nephrin compared to control sections, which in total results in an increased level of nephrin per glomerulus. In summary, our data show that in the course of mesangioproliferative glomerulonephritis in rats, an upregulation of nephrin expression occurs with a concomitant transient downregulation of podocin and CD2AP which may account for a highly dysregulated filtration barrier and increased proteinuria.