Fumarate mitigates disruption induced by fenpropathrin in the silkworm Bombyx mori (Lepidoptera): A metabolomics study

The silkworm Bombyx mori L. is a model organism of the order Lepidoptera. Understanding the mechanism of pesticide resistance in silkworms is valuable for Lepidopteran pest control. In this study, comparative metabolomics was used to analyze the metabolites of 2 silkworm strains with different pesticide resistance levels at 6, 12, and 24 h after feeding with fenpropathrin. Twenty-six of 27 metabolites showed significant differences after fenpropathrin treatment and were classified into 6 metabolic pathways: glycerophospholipid metabolism, sulfur metabolism, glycolysis, amino acid metabolism, the urea cycle, and the tricarboxylic acid (TCA) cycle. After analyzing the percentage changes in the metabolic pathways at the 3 time points, sulfur metabolism, glycolysis, and the TCA cycle showed significant responses to fenpropathrin. Confirmatory experiments were performed by feeding silkworms with key metabolites of the 3 pathways. The combination of iron(II) fumarate + folic acid (IF-FA) enhanced fenpropathrin resistance in silkworms 6.38 fold, indicating that the TCA cycle is the core pathway associated with resistance. Furthermore, the disruption of several energy-related metabolic pathways caused by fenpropathrin was shown to be recovered by IF-FA in vitro. Therefore, IF-FA may have a role in boosting silkworm pesticide resistance by modulating the equilibrium between the TCA cycle and its related metabolic pathways.     

人源诱导多能干细胞体外定向分化为功能性肝细胞的方法研究

摘要 目的：研究开发一种简易、快速在体外使多能诱导干细胞（induced pluripotent stem cells,iPSCs）定向分化为功能性肝样细胞的培养方法。方法：根据正常肝细胞在体内的发育规律,设计简化诱导方法使iPS细胞定向分化为内胚层细胞,应用qPCR和流式细胞术鉴定其纯度后进一步诱导分化为肝样细胞,并通过qPCR、ELISA、免疫荧光等技术鉴定肝细胞的性状和功能。结果：iPS细胞诱导7天后, OCT4和NANOG的表达水平显著下降,内胚层细胞相关基因CXCR4、FOXA2和HNF4A表达水平明显升高。内胚层细胞继续诱导培养15天后,肝细胞特异性标志基因ALB、TDO2、RBP4、G6PC和肝药酶基因CYPs等显著上调,同时产生高水平的白蛋白和尿素;PAS糖原染色为阳性,能主动摄取和释放吲哚菁绿,证实诱导成的肝样细胞具备正常肝细胞的部分功能。结论：该诱导方案能够在体外使iPS细胞遵循正常肝脏发育通路简易、高效地分化为功能性肝细胞。本研究为大量获得iPS来源的肝细胞及其在细胞疗法和药筛模型中的运用提供了可能性。     

多药耐药菌感染重症肺炎患者预后的危险因素分析

摘要 目的：探讨多药耐药菌感染重症肺炎患者预后的危险因素。方法：选取本院2019年5月至2022年5月收治的198例重症肺炎患者,根据患者在ICU住院期间是否死亡分为存活组（121例）和死亡组（77例）。对重症肺炎患者多药耐药菌感染情况,多药耐药G⁺耐药情况,多药耐药G^-耐药情况进行分析,对影响多药耐药菌感染重症肺炎患者预后危险因素的单因素分析,将单因素分析中差异有统计学意义的变量进行多因素Logistic回归分析,筛选影响多药耐药菌感染重症肺炎患者预后的危险因素。结果：198例重症肺炎患者中,多药耐药菌感染患者60例,占比30.30 %,共分离出病原菌290株,其中多药耐药菌65株,占比22.41 %,其中占比比较高的有鲍曼不动杆菌（23.08 %）、铜绿假单胞菌（20.00 %）、金黄色葡萄球菌（20.00 %）、肠炎克雷伯菌（10.77 %）;重症肺炎患者多药耐药G⁺对青霉素、克林霉素、红霉素等具有较高的耐药性,而对万古霉素、替考拉宁、替加环素较为敏感;重症肺炎患者多重耐药G^-对多种抗菌药物均表现出耐药性,其中对头孢他啶、头孢吡肟等具有较高的耐药性;单因素分析结果显示,死亡组患者中男性、年龄≥70岁、APACHEⅡ评分≥26分、有创通气的患者占比显著高于存活组,碳青霉烯类抗生素使用的患者占比显著低于存活组（均P<0.05）,两组患者肺部基础疾病、脑血管疾病、高血压、联合使用其他抗生素的占比,以及两组患者机械通气时间比较无差异（均P>0.05）;纳入多因素非条件Logistic回归模型分析显示,男性、年龄≥70岁、APACHEⅡ评分≥26分、有创通气为多药耐药菌感染重症肺炎患者预后的危险因素（OR=1.568、1.203、2.812、1.674,均P<0.05）,而碳青霉烯类抗生素使用是多药耐药菌感染重症肺炎患者预后的保护因素（OR=0.542,P<0.05）。结论：多药耐药菌感染重症肺炎患者的主要菌株为鲍曼不动杆菌,且男性、年龄≥70岁、APACHEⅡ评分≥26分、有创通气为多药耐药菌感染重症肺炎患者预后的危险因素,而碳青霉烯类抗生素使用是多药耐药菌感染重症肺炎患者预后的保护因素。     

重症急性胰腺炎合并腹腔感染患者病原菌分布、药物敏感性分析及其院内死亡的危险因素探讨

摘要 目的：观察重症急性胰腺炎（SAP）合并腹腔感染（IAI）患者病原菌分布,分析药物敏感性,同时探讨其院内死亡的危险因素。方法：本研究纳入2017年1月~2022年1月期间来解放军联勤保障部队第九二二医院接受治疗并确诊的SAP合并IAI患者100例,采集患者腹水标本,观察其病原菌分布,分析药物敏感性。入院后收集患者人口学特征、实验室检查等资料,探讨患者院内死亡的危险因素。结果：100例SAP合并IAI患者腹水标本中,分离出186株病原菌,其中革兰阴性菌有108株,占比58.06%。革兰阳性菌51株,占比27.42%。真菌27株,占比14.52%。鲍曼不动杆菌对不同抗菌药物的敏感性均较低,大肠埃希菌对厄他培南、亚胺培南、哌拉西林／他唑巴坦、庆大霉素、美罗培南的敏感性较高,肺炎克雷伯菌对亚胺培南、美罗培南的敏感性较高,葡萄球菌属对替加环素、万古霉素、利奈唑胺的敏感性较高,屎肠球菌对替加环素、利奈唑胺的敏感性较高,粪肠球菌对氨苄西林、万古霉素、环丙沙星、替加环素的敏感性较高。单因素分析显示,SAP合并IAI患者院内死亡与器官障碍数目、膀胱压、入院时急性生理学与慢性健康状况评分（APACHE II）评分、白细胞计数（WBC）、血钙、红细胞压积（HCT）、总胆固醇（TC）、甘油三醋（TG）、降钙素原（PCT）、C反应蛋白（CRP）、动脉二氧化碳分压（PaCO₂）、动脉氧分压（PaO2）有关（P<0.05）。多因素Logistic回归分析结果显示：器官障碍数目偏多、血钙偏低、CRP偏高、APACHE II评分偏高、膀胱压偏高、PaO₂偏低、WBC偏高是导致SAP合并IAI患者院内死亡的危险因素（P<0.05）。结论：SAP合并IAI患者病原菌分布以革兰阴性菌为主,主要的革兰阴性菌、革兰阳性菌耐药率高。此外,器官障碍数目偏多、血钙偏低、CRP偏高、APACHE II评分偏高、膀胱压偏高、PaO₂偏低、WBC偏高是影响SAP合并IAI患者院内死亡的危险因素。     

Environmental risk assessment of releases of transgenic plants containing virus-derived inserts

Sequences derived from the genomes of plant viruses are being used to provide virus resistance in transgenic crop plants. Although the environmental hazards associated with the release of such plants have been discussed widely, it has not been possible to reach generally acceptable conclusions about their safety. A case-by-case approach to the risk assessment of real examples is recommended as a means of building up confidence and of indicating areas of uncertainty. A logical framework for risk assessment is suggested, a key feature of which is identification of the viruses in the release environment that may infect the transgenic plants. Each of these is considered in relation to each of the three main classes of hazard (transcapsidation, recombination and synergism), and the risk associated with each event is analysed.     

Isolation and characterization ofPleurotus ostreatus mutant strains resistant to a carboxin-derived fungicide,flutolanil

To develop a dominant genetic marker inPleurotus ostreatus, mutant strains resistant to a carboxin-derived fungicide, flutolanil, were isolated. These mutants included strains which showed resistance to 50-fold higher concentration of fluotolanil than the wild-type strain, even after successive cultivations in the absence of the drug. Dominance of the phenotype was confirmed by back-crossing between the resistant and wild-type monokaryons. The flutolanilresistance was also shown to be stably inherited by the basidiospore-derived progenies of the mutant strains.     

Interaction of chlorpromazine with phospholipid membranes

The interaction of chlorpromazine (CPZ) with artificial membranes (egg-yolk phosphatidylcholine liposomes) has been studied. Measurements of the surface electric potential, which is modified in the presence of the ionized form of the drug, were obtained by electron paramagnetic resonance spectroscopy (EPR) using a positively charged amphiphilic spin-probe. This probe partitions between the aqueous and lipidic phases depending on the surface potential and on the structural state of the membrane. The surface potential was measured as a function of drug concentration in the range where the spectral line-shapes are not affected by the incorporation of the drug. From these experimental results and through an appropriate formalism we obtain information on the binding of the drug to the lipid bilayer and on the ionization of the drug in the lipidic phase. Correspondence to: C. Anteneodo     

Establishing apoptosis resistant cell lines for improving protein productivity of cell culture

The authors established apoptosis resistant COS–1, myeloma, hybridoma, and Friend leukemia cell lines by genetically engineering cells, aiming at more efficient protein production by cell culture. COS–1 cells, which are most widely used for eukariotic gene expression, were transfected with human bcl–2 gene. Both bcl–2 and mock transfected COS–1 cells were cultured at low (0.2%) serum concentration for 9 days. The final viable cell number of the bcl–2 transfected cells was ninefold of that of the mock transfectants. Both bcl–2 and mock transfectants were further transfected with the vector pcDNA- containing SV40 ori and immunoglobulin gene for transiently expressing protein. The bcl–2 expressing COS–1 cells produced more protein than the mock transfected COS–1 cells after 4 days posttransfection.Mouse myeloma p3-X63-Ag.8.653 cells, which are widely used as the partner for preparing hybridoma, and hybridoma 2E3 cells were transfected with human bcl–2 gene. Both bcl–2 transfected myeloma and hybridoma survived longer than the corresponding original cells in batch culture. The bcl–2 transfected 2E3 cells survived 2 to 4 four days longer in culture, producing 1.5- to 4-fold amount of antibody in comparison with the mock transfectants.Coexpression of bag–1 with bcl–2 improved survival of hybridoma 2E3 cells more than bcl–2 expression alone. The bag–1 and bcl–2 coexpressing cells produced more IgG than the the cells expressing bcl–2 alone.Apoptosis of Friend murine erythroleukemia(F-MEL) cells was suppressed with antisense c-jun expression. The antisense c-jun expressing cells survived 16 days at non-growth state.     

Physicochemical characterization and in vitro interaction with brain capillary endothelial cells of artificially monoacylated ribonucleases A

Acylated proteins play a crucial role in cellphysiology because of their increased interaction withmembranes. Their isolation is difficult as aconsequence of their low cellular concentration andtheir chemical preparation is problematic due tosolubility problems. Through the use of reversedmicelles, we produced tens of milligrams of acylatedribonucleases A, chosen as a model, purified them bysemi-preparative high performance liquidchromatography (HPLC) and characterized them by analyticalHPLC, capillary electrophoresis, mass spectrometry, peptide mapping, Edman degradation and enzyme activity. We nextscrutinized the interaction with an in vitro blood–brainbarrier model and demonstrated that palmitoylated andstearoylated ribonucleases A are transported from onecompartment to the other across the cellular monolayer,in contrast to the native enzyme.