我国弓形虫Chinese 1优势基因型感染对小鼠脑组织铁代谢影响

目的　探讨我国弓形虫Chinese 1优势基因型感染对宿主脑组织铁代谢及脑损伤的影响。方法　将20只C57BL/6（体质量15～17 g）小鼠随机分为对照组和感染组，每组10只。感染组每只小鼠腹腔注射4 000个弓形虫Chinese 1优势基因型TgCtwh3虫株速殖子，对照组小鼠注射等量无菌PBS，饲养6 d后处死小鼠并取其脑组织。采用电感耦合等离子体质谱法（inductively coupled plasma mass spectrometry, ICP⁃MS）检测小鼠脑组织铁元素水平；采用RNA芯片检测两组小鼠脑组织差异基因数目并对功能基因表达情况进行基因本体论（Gene Ontology, GO）功能富集；采用实时荧光定量PCR（fluorescent quantitative real⁃time PCR, qPCR）技术检测小鼠脑组织中弓形虫表面抗原1（Toxoplasma gondii surface antigen 1，TgSAG1）基因及部分锌铁调控蛋白（Zrt⁃ and Irt⁃like protein, ZIP）家族mRNA表达水平；采用光镜和电镜观察小鼠脑组织海马齿轮回（dentate gyrus, DG）超微结构；采用Western blotting检测谷胱甘肽过氧化物酶4（glutathione peroxidase 4, GPx4）蛋白表达水平；采用硫代巴比妥酸（TBA）法检测丙二醛（malondialdehyde, MDA）水平；采用免疫组化检测血管内皮生长因子（vascular endothelial growth factor, VEGF）蛋白表达光密度（optical density, OD）值。结果　光镜下可见感染组小鼠脑组织海马DG区细胞坏死，电镜下见感染组小鼠脑组织海马区出现胞质空泡化、核皱缩坏死、线粒体嵴断裂消融、自噬小体增加等超微结构变化。与对照组相比，感染组小鼠脑组织中铁元素水平上调[（32.92 ± 0.90） µg/g vs.（37.72 ± 1.10） µg/g；t = 3.397, P < 0.01]；RNA芯片检测感染组小鼠脑组织发现721个基因上调、276个基因下调，差异表达基因在金属离子结合能力上有明显富集。与对照组相比，感染组小鼠脑组织金属元素转运体ZIP2 mRNA表达水平上调（t = 8.659，P < 0.05）、GPx4表达下降[（1.046 ± 0.025） vs. （0.720 ± 0.101）；t = 3.129，P < 0.01]）、MDA水平升高[（4.37 ± 0.33） nmol/mgprot vs.（5.93 ± 0.54） nmol/mgprot；t = 2.451，P < 0.05）]、VEGF蛋白平均OD值上调[（0.348 3 ± 0.017 8） vs. （0.490 6 ± 0.010 5）；t = 6.641，P < 0.01]。结论　Chinese 1优势基因型弓形虫感染后，小鼠脑组织中铁元素蓄积、抗氧化能力下调、氧化应激水平升高，提示弓形虫感染可影响宿主脑组织铁代谢而导致脑损伤。     

社区严重精神障碍患者规律面访情况及其影响因素研究

背景严重精神障碍患者因自知力欠缺及高复发性、高致残性等特点，对社会稳定造成严重威胁。做好社区面访管理工作意义重大，通过定期面访患者本人，可以更好地综合评估患者病情，以便及时采取措施，提高管理服务质量。目的了解社区严重精神障碍患者规律面访情况及其影响因素，为提高社区患者的面访服务管理质量提供参考依据。方法2020年10—12月，利用2019年底江苏省严重精神障碍管理系统中建档管理的无锡市严重精神障碍患者基础档案及随访管理信息，分析当年度无锡市社区严重精神障碍患者规律面访情况，采用Logistic回归分析规律面访的影响因素。结果共纳入27 778例研究对象，其规律面访率为81.08%（22 523/27 778）。Logistic回归分析结果显示，非本地户籍〔OR（95%CI）=0.704（0.640，0.775）〕、年龄≤44岁〔OR（95%CI）=0.522（0.472，0.578）〕、学历为高中及以上〔高中/中专OR（95%CI）=0.493（0.446，0.545），大专及以上OR（95%CI）=0.470（0.415，0.532）〕、目前有正式工作〔OR（95%CI）=0.715（0.668，0.766）〕、未婚〔OR（95%CI）=0.746（0.665，0.838）〕、经济状况为非贫困〔OR（95%CI）=0.587（0.517，0.666）〕、没有进行抗精神病药物治疗〔OR（95%CI）=0.491（0.440，0.548）〕、服药时长0~10年〔OR（95%CI）=0.881（0.778，0.998）〕、不是"以奖代补"监护补助对象〔OR（95%CI）=0.807（0.704，0.926）〕、不参加社区康复服务〔OR（95%CI）=0.844（0.716，0.996）〕是患者规律面访的消极影响因素（P<0.05）。结论无锡市社区严重精神障碍患者规律面访率尚需进一步提高，应重点关注非本地户籍、年龄≤44岁、高中及以上学历、目前有正式工作、未婚、经济非贫困、没有进行抗精神病药物治疗、服药时长0~10年、不是监护补助对象和不参加社区康复服务的社区严重精神障碍患者。可通过制定倾斜性政策、开展宣传教育、降低患者病耻感、改善患者疾病认知、加强患者社会支持等措施提高患者规律面访率。     

Metabolism of non-steroidal anti-inflammatory drugs (NSAIDs) by Streptomyces griseolus CYP105A1 and its variants

In the field of drug development, technology for producing human metabolites at a low cost is required. In this study, we explored the possibility of using prokaryotic water-soluble cytochrome P450 (CYP) to produce human metabolites. Streptomyces griseolus CYP105A1 metabolizes various non-steroidal anti-inflammatory drugs (NSAIDs), including diclofenac, mefenamic acid, flufenamic acid, tolfenamic acid, meclofenamic acid, and ibuprofen. CYP105A1 showed 4′-hydroxylation activity towards diclofenac, mefenamic acid, flufenamic acid, tolfenamic acid, and meclofenamic acid. It should be noted that this reaction specificity was similar to that of human CYP2C9. In the case of mefenamic acid, another metabolite, 3′-hydroxymethyl mefenamic acid, was detected as a major metabolite. Substitution of Arg at position 73 with Ala in CYP105A1 dramatically reduced the hydroxylation activity toward diclofenac, flufenamic acid, and ibuprofen, indicating that Arg73 is essential for the hydroxylation of these substrates. In contrast, substitution of Arg84 with Ala remarkably increased the hydroxylation activity towards diclofenac, mefenamic acid, and flufenamic acid. Recombinant Rhodococcus erythrocyte cells expressing the CYP105A1 variant R84A/M239A showed complete conversion of diclofenac into 4′-hydroxydiclofenac. These results suggest the usefulness of recombinant R. erythropolis cells expressing actinomycete CYP, such as CYP105A1, for the production of human drug metabolites.     

Role of site-directed mutagenesis and adjuvants in the stability and potency of anthrax protective antigen

Anthrax is a zoonotic infection caused by the gram-positive, aerobic, spore-forming bacterium Bacillus anthracis. Depending on the origin of the infection, serious health problems or mortality is possible. The virulence of B. anthracis is reliant on three pathogenic factors, which are secreted upon infection: protective antigen (PA), lethal factor (LF), and edema factor (EF). Systemic illness results from LF and EF entering cells through the formation of a complex with the heptameric form of PA, bound to the membrane of infected cells through its receptor. The currently available anthrax vaccines have multiple drawbacks, and recombinant PA is considered a promising second-generation vaccine candidate. However, the inherent chemical instability of PA through Asn deamidation at multiple sites prevents its use after long-term storage owing to loss of potency. Moreover, there is a distinct possibility of B. anthracis being used as a bioweapon; thus, the developed vaccine should remain efficacious and stable over the long-term. Second-generation anthrax vaccines with appropriate adjuvant formulations for enhanced immunogenicity and safety are desired. In this article, using protein engineering approaches, we have reviewed the stabilization of anthrax vaccine candidates that are currently licensed or under preclinical and clinical trials. We have also proposed a formulation to enhance recombinant PA vaccine potency via adjuvant formulation.