盐酸芬氟拉明对映体的柱前衍生物GC法分析

以ω－莰烷酰氯为衍生试剂,采用柱前衍生化ＧＣ法,成功地分析了盐酸芬氟拉明、金刚乙胺和盐酸氯胺酮。光谱分析确证了芬氟拉明酰胺衍生物的结构,优化了盐酸芬氟拉明酰胺衍生物的结构,优化了盐酸芬氟拉明衍生条件,建立了盐酸花氟拉明的内标法定量分析方法。     

川白芷药材中有机磷类农药残留量的测定

目的 制定川白芷药材中有机磷类农药最大残留的限量标准(MRLs).方法采用乙酸乙酯冰浴超声提取,SPE活性炭固相萃取柱净化除杂质,GC - NPD法检测药材中有机磷类农药的残留量.结果建议将川白芷药材中有机磷类农药的最大残留限量规定为:敌敌畏0.2μg·g-1、乙酰甲胺磷0.5μg·g-1、乐果0.2 μg·g-1、马...     

GC-MS分析苦豆子总碱中的13种生物碱

目的 定性、定量分析苦豆子中的生物碱.方法 采用732强酸性阳离子交换树脂法、Hydromatrix为基质的固相萃取法和有机溶剂液液萃取法制备新疆苦豆子总碱,并用GC-MS法分析总碱中生物碱的组分及相对含量.结果 3种方法提取的苦豆子总碱中各生物碱单体的组分类型相同;GC-MS法共检出13种生物碱,主要为槐定碱、槐果碱、苦参碱、异槐果碱、野啶碱、Lamprolobine和槐胺碱,占13种生物碱的相对百分含量分别为32.63%、19.99%、12.52%、9.25%、8.47%、6.16%、4.11%.结论 GC-MS法能够快速准确地检测苦豆子中槐定碱、苦参碱等多种生物碱成分.     

柱前衍生化GC法测定旱芹非淀粉多糖中各单糖组分含量

目的建立测定旱芹非淀粉多糖中各单糖组分含量的柱前衍生化GC法。方法非淀粉多糖经衍生化生成糖腈乙酯,采用GC法进行分析。色谱柱:DB-17柱(30 m×0.25 mm,0.25μm);柱温:程序升温;载气:N2;进样温度:270℃;进样方式:不分流;检测器温度:270℃;进样量:1.0μL。结果水不溶性非淀粉多糖(insoluble non-starch polysaccharides,INSP)水解后得到7种单糖,分别是:L-(+)-鼠李糖、L-(+)-阿拉伯糖、D-(+)-岩藻糖、D-(+)-木糖、D-(+)-甘露糖、D-(+)-葡萄糖和D-(+)-半乳糖;水溶性非淀粉多糖(soluble non-starch polysaccharides,SNSP)水解后得到6种单糖,除无D-(+)-岩藻糖外,其余均同INSP水解后单糖。结论本方法准确度高,重现性好,可用于测定旱芹水溶性和水不溶性非淀粉多糖中各单糖组分的含量。     

气相色谱法测定扎来普隆中二氯甲烷和N,N-二甲基甲酰胺的残留量

 目的建立毛细管气相色谱法测定扎来普隆中二氯甲烷和N,N-二甲基甲酰胺的残留量。方法采用DB-624熔融石英毛细管柱(30 m×0.32 mm,1.8μm);载气:氮气;分流比:60∶1。二氯甲烷的测定:以N,N-二甲基甲酰胺为溶剂;氯仿为内标;柱温:40℃,保持15 min,以40℃·min^-1的速率升温至180℃,保持10 min;气化室温度:180℃;检测器温度:200℃(FID)。N,N-二甲基甲酰胺的测定:以二氯甲烷为溶剂;甲苯为内标;柱温:85℃;气化室温度:200℃;检测器温度:200℃(FID)。结果二氯甲烷在15.02～150.2 mg·L^-1内线性关系良好,r=0.999 7(n=5),最低检出限为4.5 mg·L^-1,连续进样精密度RSD为1.8%,回收率为99.48%(RSD=0.9%)。N,N-二甲基甲酰胺在22.02～264.2 mg·L^-1内线性关系良好,r=0.999 7(n=5),最低检出限为4.4 mg·L^-1,连续进样精密度RSD为1.2%,回收率为99.55%(RSD=2.7%)。结论本方法可用于测定扎来普隆中二氯甲烷和N,N-二甲基甲酰胺的残留量。     

Decreased expression of claudin-18.2 in alpha-fetoprotein-producing gastric cancer compared to conventional gastric cancer

BackgroundAlpha-fetoprotein-producing gastric cancer (AFPGC) is a subtype of gastric cancer (GC) with more aggressive biological behavior. As a highly specific tight junction component exclusively present in gastric mucosa and gastric adenocarcinomas, claudin-18.2 (CLDN18.2) has become an emerging target in GC. In this study, we aimed to provide insight into AFPGC and investigate the expression and the clinical implications of CLDN18.2 in AFPGC.MethodsWe retrospectively collected 98 cases of AFPGC and reviewed their clinical, morphological, and immunohistochemical features. Another 356 patients with stage-matched conventional GC (cGC) were enrolled as a control group. We further surveyed CLDN18.2 expression by immunohistochemistry (IHC) in 51 AFPGC tissues and explained its association with the clinicopathological parameters of AFPGC.ResultsOur results showed that AFPGC was a unique GC type with elevated serum alpha-fetoprotein (AFP), which was a predictor of a worse prognosis. AFPGC showed typical morphological features and positive staining of at least 1 hepatocytic or enteroblastic marker. The expression rate of CLDN18.2 was low, with a positivity rate of 21.6%, which was much lower than that observed in cGC tissues (38.5%). A significant correlation was found between CLDN18.2 expression and the differentiation of AFPGC. CLDN18.2 expression was negatively correlated with the serum AFP level of AFPGC. We also found that AFPGC with a hepatoid type (HPT) component showed a significantly lower CLDN18.2 expression than those without.ConclusionsThis study demonstrated that CLDN18.2 was significantly decreased in AFPGC and was negatively correlated with the patient’s preoperative serum AFP level. The negative correlation between AFP and CLDN18.2 could be explained by retro-differentiation of AFPGC. Special treatment strategies might be needed for this unique tumor type.     

Abrogation of ARF6 in promoting erastin-induced ferroptosis and mitigating capecitabine resistance in gastric cancer cells

BackgroundADP ribosylation factor 6 (ARF6) is a member of the Rat sarcoma virus (RAS) superfamily that is involved in the regulation of vesicular trafficking, membrane lipid remodeling, and signaling pathways. Our earlier work discovered that ARF6, as a downstream effector of the Kirsten rat sarcoma viral oncogene (Kras)/extracellular signal-regulated kinases (ERK) signaling pathway, may increase proliferation and induce the Warburg effect in gastric cancer (GC) cells. Additionally, ARF6 appears to be a potential biomarker for predicting the prognosis of GC. Ferroptosis has recently been described as a type of nonapoptotic iron-dependent cell death that is strongly associated with the Kras mutation. Therefore, it is critical to continue investigating the link between ARF6 and ferroptosis.MethodsWe first created ARF6 silenced cancer cell lines with lentivirus transfection. The knockdown efficiency was confirmed through quantitative polymerase chain reaction (qPCR) and western blotting. Subsequently, we used Cell Counting Kit-8 (CCK-8) and malondialdehyde (MDA) assay for lipid peroxidation measurement. Following this, qPCR and western blotting were conducted to clarify the mechanism involved. Finally, immunohistochemistry was used to stain human GC samples.ResultsOur findings established that, whereas ARF6 did not directly regulate lipid peroxidation, it did render GC cells susceptible to oxidative stress, particularly erastin-induced lipid peroxidation. Additionally, our research demonstrated that ARF6 may control capecitabine resistance via several routes.ConclusionsARF6 may play a critical role in the development of GC.     

气相色谱法测定通络祛痛膏中樟脑、薄荷脑和冰片含量

目的建立测定通络祛痛膏中樟脑、薄荷脑和冰片中龙脑含量的气相色谱法。方法采用AgilentDB—WAX弹性石英毛细管色谱柱（30m×0．32mnl,0．5μm）,载气为氮气,分流比为30：1,柱温为140oC,进样口温度为220℃,检测器温度为250℃。结果樟脑、薄荷脑和龙脑进样量分别在0．224～6．725μg（r=0．9999）,0．103～3．088扯g（r=O．9999）,0．060～1．811μg（r=0．9999）fg围内与峰面积呈良好线性关系,平均回收率分别为98．76％,97．36％,100．96％,RSD分别为0．60％,0．67％,0．67％（n=6）。结论该方法简便、准确．可用于通络祛痛膏中樟脑、薄荷脑和龙脑的含量测定及其质量控制。     

气相色谱法测定维生素K1注射剂中1，2-丙二醇的含量

目的建立GC法测定维生素K1注射剂中1,2-丙二醇的含量。方法采用Agilent DB—WAX气相毛细管柱（0．32mm×30m,0．25μm）,FID检测器,程序升温：80℃维持1min,再以10℃·min^-1升温至230℃维持4min,进样口温度：230℃,检测器温度：250℃。结果维生素K1注射剂中1,2．丙二醇在0．1025～4．0998nag·mL^-1与峰面积呈良好线性关系（r=0．9999）,平均回收率为97．5％,RSD为0．40％（n=9）。结论本方法准确度高、重现性好,可用于维生素K1注射剂中1,2-丙二醇含量的测定。     

气相色谱法测定羟乙基淀粉摩尔取代级

目的:建立一种快速、准确的羟乙基淀粉摩尔取代级测定方法。方法:以氢碘酸水解羟乙基淀粉中的羟乙基成碘乙烷,用气相色谱法测定。色谱柱:CP-Sil 5CB(10％甲基硅酮,25 m ×0.25 mm,膜厚0.4μm),检测器:氢火焰离子化检测器(FID),柱温:100℃,进样器温度:200℃,检测器温度:300℃,载气:N_2,流速:1mL·min~(-1),分流比:1:3O,内标:甲苯,对照品:碘乙烷。结果:方法重现性良好,RSD为2.7％(n=5);回收率为98.2％(n=5)。分析了5批样品,结果与用Zeisel法测定结果基本一致。结论:本方法分离效率高,专属性好,可作为该品种摩尔取代级的测定方法。