Identification of volatile organic compounds in muscle tissues of different species based on Headspace-Gas-Chromatography Ion-Mobility spectrometry

Species identification of unknown biological samples is crucial for forensic applications, especially in cases of explosion, disaster accidents, and body mutilation after murdering, as well as poaching, illegal trade in endangered animals, and meat food fraud. In this study, we identified 60 volatile organic compounds (VOCs) in fresh skeletal muscle tissues of seven different animal species (cattle, sheep, pigs, rabbits, rats, chickens and carp) and a human dead body by headspace-gas-chromatography ion-mobility spectrometry (HS-GC-IMS), and compared their differences by retention time, drift time and molecular weight. The results showed that these VOCs formed different gallery plot fingerprints in the skeletal muscle tissues of the human dead body and seven animal species. Principal component analysis (PCA) showed significantly different fingerprints between these species, and these fingerprints maintained good stability between the species and within the same species. Some VOCs have high species specificity, while VOCs of human fresh muscle tissues from different individual sources have little difference, demonstrating that all tested muscle tissue samples could be distinguished based on different VOCs. HS-GC-IMS has proved to be a rapid, high-throughput, highly sensitive and specific species identification method, which can be used for forensic species identification in criminal cases and disaster accidents, as well as detection in the field of food safety, such as meat fraud and adulteration.     

应用逆转录病毒载体转染K562细胞株的实验研究

目的:探讨多种细胞因子联合刺激下,逆转录病毒载体对K562细胞的基因转移效率。方法:以PA317-GCGPXSN细胞制备病毒上清,NIH3T3细胞测定病毒滴度后,取经过SCF、IL-3、IL-6预培养刺激后的K562细胞,实施基因转移,流式细胞仪及PCR方法测定基因转移效率。结果:①病毒滴度为1.9×105CFU/m l;②对照组K562细胞测定的荧光强度数值为0.56%,实验组为77.16%,两者差异有统计学意义(P<0.01)。PCR方法扩增到了NeoR基因的特异性片断。结论:细胞因子预刺激后实施基因转移,可有效地将外源基因转移进入K562细胞基因组中。     

Labeling of human insulin-like growth factor-I eukaryotic expression vector with green fluorescent protein

Articularcartilageinjuriesinadultsarecommon.Theintrinsicrepairisgenerallyminimalandcartilageinjuriescanfurtherdevelopintoosteoarthritis.Insulin likegrowthfactor I(IGF I)is regardedasoneofthemostimportantgrowthfactorsin cartilagedevelopmentandhomeostasis.Theadditionof IGF Itochondrocytesinvitroenhanceschondrocyte metabolism,maintainsadifferentiatedchondrocyte morphologyandpromotessynthesisofmajorcartilage matrixproteins,includingtype IIcollagenand proteoglycans.1,2IGF Iinlowconcentrationi…     

红色荧光蛋白标记的裸鼠胰腺癌转移模型的建立

目的 建立稳定、高表达红色荧光蛋白标记的裸鼠胰腺痛转移模型.方法 将RFP基闪转入人胰腺癌细胞株SW1990.评价转染前后细胞生物学行为有无改变,并采用SW1990-RFP建立实验性肺转移模型和实验性肝转移模型.应用整体荧光成像系统评价各组转移模型肿瘤转移的发生.结果 获得稳定,高表达RFP的单克隆细胞系SW1990-RFP,转染前后细胞生物学行为无明显改变.成功建立了裸鼠胰腺癌实验性肺转移模型和肝转移模型,并应用整体荧光成像系统检测到各脏器微小转移的发生.建模成功率均为66.7%(4/6).结论 RFP基因不改变SW1990的细胞生物学行为,本实验所建立的裸鼠胰腺癌转移模型稳定、可靠,具有较强的灵敏性及特异性.     

骨髓来源细胞移植对实验性肾小球肾炎小鼠的作用

目的：利用骨髓移植的方法观察骨髓来源细胞在小鼠实验性肾小球肾炎中的作用。方法：以绿色荧光蛋白（GFP）标记的C57BL／6转基因小鼠为供体,同种无标记小鼠为受体鼠,受体鼠在接受供体骨髓细胞前经亚致死剂量^60Co照射。并于移植5周后以尾静脉注射的方式接受竹叶青蛇毒注射;蛇毒注射后7、14、28、56d利用免疫组织化学和免疫荧光双重染色方法观察受体鼠肾脏内的GFP阳性细胞及受体鼠肾脏病理变化,其中一组受体鼠在蛇毒注射后接受连续1周的粒巨系一集落刺激因子（GM-CSF）腹腔注射,观察GM-CSF对骨髓来源细胞及受体鼠的影响。结果：无论有无蛇毒损伤,荧光显微镜下受体鼠肾脏内均未见明亮的绿色荧光。GFP免疫组织化学可见所有受体鼠的肾小管上皮内均有少量细胞质棕褐色、细胞核大且紫蓝的GFP阳性细胞,包括那些骨髓移植后无蛇毒损伤的受体鼠;肾小球内也可见上述细胞,但在无蛇毒损伤的受体鼠内肾小球内未见上述细胞;激光共聚焦显微镜未见到明显双染色阳性的细胞,从形态上证实肾小球内的这些GFP阳性细胞大多为血细胞。那些接受GM-CSF注射的受体鼠肾脏内,GFP阳性细胞没有明显增加,而且肾脏损伤恶化,表现为蛇毒注射后1周出现了明显的局灶性节段性肾小球硬化。结论：骨髓来源细胞在蛇毒诱导的系膜增生型肾小球肾炎小鼠肾脏内向肾小管和肾小球细胞均可少量转化,但由于转化率低及肾小球结构的复杂性,向肾小球细胞的转化更加不易被识别;GM-CSF注射未能增加外源性骨髓细胞向肾脏实质细胞的转化而使受体鼠肾脏损伤恶化,于病程早期出现了局灶性节段性肾小球硬化。     

Inhibition of Growth and Metastasis of Tumor in Nude Mice after Intraperitoneal Injection of Bevacizumab

Objective

To explore the inhibitory effect of bevacizumab, a vascular endothelial growth factor antibody, on angiogenesis in human osteosarcoma of nude mice.

Methods

Twenty‐one nude mice were inoculated with red fluorescent protein (RFP)‐labeled human osteosarcoma cell line 143B‐RFP, that is, clones that expressed RFP in the cytoplasm, and randomly assigned to one of three groups: G1 (Control group, injected with saline solution); G2 (intraperitoneal bevacizumab 2 mg/kg twice per week) and G3 (intraperitoneal bevacizumab 5 mg/kg, twice per week). The tumor‐bearing mice were examined in a fluorescence light box that was illuminated periodically. The primary tumors were measured by fluorescence imaging weekly and their volumes calculated.

Results

The mean tumor volumes were significantly smaller in the G3 (186.4 ± 100.8 mm³) than the control group (587.0 ± 406.8 mm³) (P < 0.05) on Day 31, and again significantly smaller in the G3 (677.3 ± 461.9 mm³) than the control group (3162.6 ± 1529.2 mm³) on Day 38 (P < 0.01). The average tumor volume in the G2 group was 493.5 ± 425.4 mm³ on Day 31 and 1870.1 ± 1524.8 mm³ on Day 38. The effect on tumor volume was greater in the G3 than the G2 group. Three mice in the G2 group, four in the G3 group and four in the control group developed lung metastases that were confirmed by pathological examination; these differences were not statistically significant (P < 0.05).

Conclusions

Bevacizumab exhibits strong antiangiogenesis activity in experimental osteosarcoma in a nude mouse model but does not influence the incidence of lung metastasis. Our findings may have considerable potential for the treatment of osteosarcoma.     

采用组织芯片技术分析胃癌组织中胃泌素和胃泌素释放肽的表达

目的研究胃癌组织中胃泌素(GAS)、胃泌素释放肽(GRP)的表达及其临床意义。方法采用组织芯片技术制作60例胃癌组织芯片,同时用生物素-链霉菌卵白素检测系统(SP)免疫组织化学方法检测胃癌组织芯片中GAS、GRP的表达。结果60例胃癌中GAS阳性率为30.0%;GRP阳性率为11.7%。中、低分化胃癌GAS、GRP阳性率高于高分化胃癌(P<0.05);印戒细胞癌GAS、GRP阳性率显著高于其他组织学类型胃癌(P<0.05);胃癌GAS、GRP阳性表达与淋巴结转移相关(P<0.05)。结论应用组织芯片大规模高效检测临床组织样本是可行的,具有快速、方便、经济、准确的特点。     

Vascular Endothelial Growth Factor C Promotes Lymph Node Metastasis in a Rectal Cancer Orthotopic Model

Purpose Vascular endothelial growth factor C (VEGF-C), a novel member of the vascular endothelial growth factor family, is a relatively specific lymphangiogenic growth factor. It has been suggested that increased expression of VEGF-C in primary tumors is correlated with lymph node metastasis. We conducted this study to determine whether VEGF-C directly affects lymphangiogenesis and lymph node metastasis in colorectal cancer.Methods For an accurate analysis and clear visualization of metastases, the rectal cancer cell line, DLD1, was engineered to stably express green fluorescent protein (GFP) (DLD1/GFP). We implanted DLD1/GFP cells overexpressing VEGF-C orthotopically into the rectal walls of nude mice.Results Lymph node metastasis was confirmed in all (100%) of the mice bearing DLD1/GFP-VEGF-C tumors, but in only 25% of the mice bearing control tumors. There were more lymph node metastases per mouse in the mice bearing DLD1/GFP-VEGF-C tumors than in the mice bearing control tumors. There were no differences in cell growth and motility in vitro or in the resulting tumor volume from the implanted cells between the two groups. Immunohistochemical staining revealed that VEGF-C induced the growth of lymphatic vessels, which were enlarged in the tumor periphery and contained tumor cell emboli.Conclusion These results suggest that VEGF-C-induced lymphangiogenesis mediates tumor spread and the formation of lymph node metastasis.     

BOPPPS教学模式在医科院校医用化学教学中的应用与思考

医用化学是医学院校一门重要的基础必修课程,内容多为知识理解型,这导致了学生兴趣薄弱,学习效果欠佳。因此,需要通过改革传统"灌输式"课堂授课方式,让学生真正参与到教学活动中。BOPPPS教学模式分为导言、学习目标、前测、参与式学习、后测和总结六个环节。突出"以学生为中心"的教学理念,遵循教学活动的客观规律。在医用化学课程的教学过程中引入BOPPPS教学,能够有效提高学生的课堂参与度,增强学生的学习动力,培养学生独立思考、自主学习的能力。     

浅谈中药化学教学的体会

中药化学是药学教学的一门重要课程。教学工作是教师“教”与学生“学”的双边活动，而在教师与学生两个方面，教师应起主导作用。在搞好中药化学的教学中，主要抓了认真备课。在愉快的心情下进行教学，重视辅导与考查等环节，取得了一定效果。