香叶挥发油成分分析及其对 小鼠白色假丝酵母菌阴道病的影响

目的 研究香叶挥发油对白色假丝酵母生物膜形成的影响。方法 水蒸气蒸馏法提取香叶挥发油,GC-MS分析其成分,测定其对白色假丝酵母的MIC、MBC,激光共聚焦显微镜下观察白色假丝酵母生物膜的形成,制备小鼠白色假丝酵母菌阴道病模型,观察香叶油治疗效果。结果 香叶挥发油提取率为1.83%,分析出22个成分,主要成分为5-甲基-2-异丙烯基环己酮、3,7-二甲基-2-辛烯-1-醇、(顺)香叶醇、异香叶醇、香叶醇和甲酸香茅酯,MIC值为0.3625%,MBC值为0.6250%,激光共聚焦结果显示不同浓度香叶油均可显著抑制白色假丝酵母生物膜形成,动物实验结果显示香叶油可抑制小鼠阴道炎症改变。结论 香叶油用于治疗白色假丝酵母引起的阴道炎机制可能与其影响细菌生物膜形成有关。     

《中国药典》中标准菌种质控新方法的研究

目的 研究《中华人民共和国药典》(简称《中国药典》)纳入的标准菌种质控新方法,并评价不同批号标准菌种的质量稳定性。方法 对脉冲场凝胶电泳(PFGE)技术进行比较研究,同时整合16SrRNA基因序列分析、多位点序列分型和基质辅助激光解吸电离飞行时间质谱等质控新方法,进行标准菌种质控新方法的建立,并对标准菌种的质量进行评价。结果 形成了适用于《中国药典》中标准菌种的方法,并通过整合的质控新方法对不同批号的标准菌种进行评价,结果显示,菌种质量稳定,遗传信息无改变。同时,建立了标准菌种16SrRNA基因标准序列、PFGE标准指纹图谱和标准基因型。结论 标准菌种质控新方法的研究,为更加全面、深入地评价标准菌种的质量提供了依据;建立的标准菌种质量控制体系及标准菌种质控鉴定信息,为标准菌种持续的质量控制奠定了重要的参比信息基础。     

A novel de novo PDE4D gene mutation identified in a Chinese patient with acrodysostosis

Acrodysostosis is an extremely rare disorder at birth, that is, characterized by skeletal dysplasia with short stature and midfacial hypoplasia, which has been reported to be caused by PDE4D and PRKAR1A gene mutations. Here, a Chinese boy with acrodysostosis, ventricular septal defect, and pulmonary hypertension was recruited for our study, and his clinical and biochemical characteristics were analyzed. A novel de novo heterozygous missense mutation (NM_001104631: c.2030A>C, p.Tyr677Ser) of the PDE4D gene was detected by whole exome sequencing and confirmed by Sanger sequencing. The c.2030A>C (p.Tyr677Ser) variant was located in exon 15 of the PDE4D gene, predicted to be damaging by a functional prediction program and shown to be highly conserved among many species. Further functional analysis showed that the p.Tyr677Ser substitution changes the function of the PDE4D protein, affects its subcellular localization in transfected cells, increases PDE4 activity in the regulation of cAMP signaling and affects cell proliferation. Our study identified a novel de novo PDE4D mutation in acrodysostosis of Chinese origin that not only contributes a deeper appreciation of the phenotypic characteristics of patients with PDE4D mutations but also expands the spectrum of PDE4D mutations.     

Production of fuels and chemicals from renewable resources using engineered Escherichia coli

Biotechnological production of fuels and chemicals from renewable resources is an appealing way to move from the current petroleum-based economy to a biomass-based green economy. Recently, the feedstocks that can be used for bioconversion or fermentation have been expanded to plant biomass, microbial biomass, and industrial waste. Several microbes have been engineered to produce chemicals from renewable resources, among which Escherichia coli is one of the best studied. Much effort has been made to engineer E. coli to produce fuels and chemicals from different renewable resources. In this paper, we focused on E. coli and systematically reviewed a range of fuels and chemicals that can be produced from renewable resources by engineered E. coli. Moreover, we proposed how can we further improve the efficiency for utilizing renewable resources by engineered E. coli, and how can we engineer E. coli for utilizing alternative renewable feedstocks. e.g. C1 gases and methanol. This review will help the readers better understand the current progress in this field and provide insights for further metabolic engineering efforts in E. coli.     

Repellent action and contact toxicity mechanisms of the essential oil extracted from Chinese chive against Plutella xylostella larvae

Botanical pesticides play increasingly important roles in the control of agricultural pests. In this study, the insecticidal effects, specifically the repellent action and contact toxicity, of the essential oil extracted from Chinese chive (EOC) against Plutella xylostella larvae were confirmed. The mechanisms of repellent’s action were studied using electroantennograms (EAGs), and the effects on glutathione S‐transferase (GST), carboxylesterase (CarE), and acetyl cholinesterase were investigated after EOC treatments. The EOC affected the EAG results and inhibited the activities of GST and CarE in treated P. xylostella larvae, which could explain its insecticidal effects. And, four pyrazines showed greater repellent activities than that of the EOC, which was confirmed as the main active compounds of EOC.     

‘Straightening What’s Crooked’? Recognition as Moral Disruption in Indonesia’s Confucianist Revival

ABSTRACT

In 2006, the Indonesian state re-recognised Confucianism as an official religion, but this did not have the straightforwardly positive consequences that either Confucianist revivalists or some theorists of recognition might have predicted. Revivalists were often – but not always – gripped by feelings of outrage and moral torment, whilst the pace of the revival itself was very uneven. These varied outcomes reflect the complex politics pervading the lives of Indonesian Confucianists (and Chinese Indonesians more generally) as post-Suharto reforms force them to grapple with their diverse histories of accommodation and resistance to the New Order’s discriminatory policies. To fully understand such material, first-person moral perspectives must be incorporated into critical anthropological studies of recognition, as a complement to approaches focused on power and domination. Doing so reveals an important general truth about recognition – its capacity to be morally disruptive – and broadens our understanding of why recognition can hurt those it ostensibly stands to benefit.     

Impacts of intentional mycoplasma contamination on CHO cell bioreactor cultures

Mycoplasma contamination events in biomanufacturing facilities can result in loss of production and costly cleanups. Mycoplasma may survive in mammalian cell cultures with only subtle changes to the culture and may penetrate the 0.2 µm filters often used in the primary clarification of harvested cell culture fluid. Culture cell-based and indicator cell-based assays that are used to detect mycoplasma are highly sensitive but can take up to 28 days to complete and cannot be used for real-time decision making during the biomanufacturing process. To support real-time measurements of mycoplasma contamination, there is a push to explore nucleic acid testing. However, cell-based methods measure growth or colony forming units and nucleic acid testing measures genome copy number; this has led to ambiguity regarding how to compare the sensitivity of the methods. In addition, the high risk of conducting experiments wherein one deliberately spikes mycoplasma into bioreactors has dissuaded commercial groups from performing studies to explore the multiple variables associated with the upstream effects of a mycoplasma contamination in a manufacturing setting. Here we studied the ability of Mycoplasma arginini to persist in a single-use, perfusion rocking bioreactor system containing a Chinese hamster ovary (CHO) DG44 cell line expressing a model monoclonal immunoglobulin G1 (IgG1) antibody. We examined M. arginini growth and detection by culture methods, as well as the effects of M. arginini on mammalian cell health, metabolism, and productivity. We compared process parameters and controls normally measured in bioreactors including dissolved oxygen, gas mix, and base addition to maintain pH, to examine parameter changes as potential indicators of contamination. Our work showed that M. arginini affects CHO cell growth profile, viability, nutrient consumption, oxygen use, and waste production at varying timepoints after M. arginini introduction to the culture. Importantly, how the M. arginini contamination impacts the CHO cells is influenced by the concentration of CHO cells and rate of perfusion at the time of M. arginini spike. Careful evaluation of dissolved oxygen, pH control parameters, ammonia, and arginine over time may be used to indicate mycoplasma contamination in CHO cell cultures in a bioreactor before a read-out from a traditional method.     

Transcriptomic analysis of IgG4 Fc-fusion protein degradation in a panel of clonally-derived CHO cell lines using RNASeq

In this study, we report an investigation of a panel of clonally-derived Chinese hamster ovary (CHO) cell lines exhibiting variability in the proportion of full-length IgG4 Fc-fusion protein produced. The recombinant protein was found to be degraded during cell culture into four shorter “clipped” species (three of the four cleavage sites occurred at arginine residues) and preliminary analyses suggested that a host cell enzyme was responsible for proteolysis. To identify the specific enzyme responsible, RNA sequencing was used to identify gene expression differences between the cell lines with a “high” and “low” clipping phenotype. From this analysis, six protease-encoding genes were found to be significantly upregulated in those cell lines yielding the lowest proportion of full-length IgG4 Fc-fusion protein. Four of these protease candidates were deprioritized after examination of their cleavage site specificity. The remaining enzymes, Adam19 and Furin, were found to be capable of cleavage at arginine residues, and inhibitors for both proteases were added to cell-free media to determine if the product degradation could be reduced. While the Adam19 inhibitor had no impact, Furin inhibitor I (specific for the proprotein convertase family of enzymes) was found to result in a 33–39% increase in complete IgG4 Fc-fusion protein when compared with untreated samples.