UVB radiation induces phosphorylation of the epidermal growth factor receptor, decreases EGF binding and blocks EGF induction of ornithine decarboxylase gene expression in SV40-transformed human keratinocytes

Abstract We previously demonstrated that epidermal growth factor (EGF) induces a several-fold increase in ornithine decarboxylase (ODC) activity and the steady-state level of ODC mRNA in cultured SV40-transformed human keratinocytes (1). Pretreatment of cell cultures with ultraviolet B (UVB) radiation resulted in a reduction of EGF-induced ODC activity. To determine whether UVB inhibits the accumulation of ODC mRNA by EGF, cells were pretreated with 20 mJ/cm² UVB or sham-irradiated and then incubated with 100 ng/ml EGF. Northern blot analysis revealed that UVB irradiation entirely blocked the EGF induction of ODC mRNA. Since the binding of EGF to its plasma membrane receptor is the first step in initiating a biological response, the effect of UVB on EGF binding was evaluated. UVB treatment of cultured keratinocytes resulted in an immediate and dose-dependent reduction of EGF binding. Scatchard analysis revealed thai the reduction of EGF binding was due to a 52% decrease in the number of available receptors, from 6.2 × 10⁴/cell to 3.0 × 10⁴/cell. However, UVB decreased the EGF-binding affinity very little (Kd = 0.60 nM in control and Kd=0.75 nM in UVB-treated Z114 cells). In addition, UVB did not alter the rate of EGF internalization. These data suggest that UVB blocks the signal transduction pathway of EGF that is involved in regulation of ODC gene expression. Immunoblot analysis of extracts from irradiated cells showed that UVB induced tyro-sine phosphorylation of EGFR and that the quantity of EGFR protein was unaffected by UVB treatment. Phosphorylation of EGFR may be responsible for decreased binding of EGF to its receptor.     

Frailty评分对枸橼酸伊沙佐米治疗多发性骨髓瘤不良反应的预测价值

目的 探讨Frailty评分对枸橼酸伊沙佐米治疗多发性骨髓瘤(multiple myeloma, MM)不良反应的预测价值。方法 选取MM患者72例,均予以枸橼酸伊沙佐米联合沙利度胺、地塞米松方案治疗,观察治疗效果及不良反应。并根据患者不良反应程度分为Ⅰ～Ⅱ级组和Ⅲ～Ⅳ级组。比较2组Frailty评分;采用Cox回归模型分析化疗相关Ⅲ～Ⅳ级不良反应的影响因素;采用ROC曲线模型分析Frailty评分对化疗相关Ⅲ～Ⅳ级不良反应的预测价值。结果 72例MM患者均实施枸橼酸伊沙佐米治疗,总有效率为80.55%;出现不良反应70例、以乏力占比最高,发生率为72.22%,其次为淋巴细胞降低25.00%、贫血18.06%,未出现任何不良反应2例。Ⅲ～Ⅳ级组Frailty评分高于Ⅰ～Ⅱ级组(P<0.05)。70例出现不良反应患者均随访12个月,其平均生存时间(22.30±2.28)个月。Cox回归分析结果显示,Frailty评分≥2分是MM患者发生Ⅲ～Ⅳ级不良反应的影响因素。ROC曲线分析显示,Frailty评分预测化疗相关Ⅲ～Ⅳ级不良反应AUC值为0.925(95%CI:0.816～1.00...     

双酚F暴露后对小鼠肝脏神经递质代谢的影响

目的：探讨双酚F（bisphenol F,BPF）对肝脏中色氨酸（tryptophan,TRP）及酪氨酸（tyrosine,TYR）代谢的影响,阐明其代谢稳态扰乱后神经递质的代谢特点。方法：SPF级C57BL/6J小鼠经灌胃给予不同浓度的BPF[40、400、4 000 μg/（kg·d）],连续灌胃30 d,通过超高效液相色谱-串联质谱（ultra-high-performance liquid chromatography-tandem mass spectrometry,UHPLC-MS/ MS）法观察BPF暴露后小鼠肝脏TRP、TYR来源神经递质代谢特点及水平的改变。结果：BPF暴露后引起小鼠肝脏TRP、TYR 水平下降,其中 TRP 代谢途径的神经递质 5-羟色胺（5-hydroxytryptamine,5-HT）水平明显下降,相反,犬尿氨酸（kynurenine, KYN）水平显著上升;TYR代谢途径中,TYR及其代谢产物多巴胺（dopamine,DA）水平显著下降;其他兴奋性神经递质如谷氨酸（glutamate,GLU）、γ-氨基丁酸（γ-aminobutyric acid,GABA）、天冬氨酸（aspartic acid,ASP）、甘氨酸（glycine,GLY）水平亦明显降低。结论：BPF暴露可抑制TRP、TYR及多个兴奋性神经递质的代谢,促进TRP通路中5-HT向KYN代谢转化,对肝脏神经递质代谢的探讨可为BPF持续暴露导致的肝脏及神经精神性病变提供依据。     

A framework for automatic analysis of the dynamic behaviour of coronary angiograms

A framework for coronary vessels analysis in digital subtracted angiograms is described. This method combines the motion estimation with the frame-to-frame structure detection in a natural way such that they act interactively. The first step consists of the extraction of the vessel centrelines in one image and their organization into meaningful constituents or branches of the coronary arterial tree. The motion is then estimated along the centrelines through a gradient based method. These motion estimates supply an initial positioning of an active contour model (or snake) in the next image. This model adapts itself by changing its shape to accurately fit onto the new centrelines. This process is then reiterated on the subsequent images to depict the dynamic behaviour of all the relevant branches. The main interests of this scheme are: (1) the active models operate locally so a fast detection of the vessels can be performed; (2) the centrelines extraction is fully guided by the confluence of the motion estimation and the contour model; (3) both morphological and kinetic features are provided on a quantitative basis.     

神经症的性压抑与心理因素的相关性研究

研究神经症患者潜在人格与性压抑和情绪的相关性.方法:对124例神经症患者进行了婚姻质量问卷(性生活、婚姻质量部份)、抑郁自评量表(以下简称SDS)、焦虑自评量表(以下简称SAS)及自编的性生活调查问卷、主题统觉测验(以下简称TAT)测评.结果:1、神经症伴性障碍组TAT潜在人格与对照组相比,在支配、性、援助、躯体社会攻击、财产破坏欲求、自我攻击、情绪变化欲求和情绪言语攻击性、躯体社会攻击、引诱、缺乏、丧失、灾害、丧失支持、躯体伤害压力上均较对照组显著增高,而成就欲求下降(P<005-001);与神经症无性障碍组相比,神经症伴性障碍组的成就、支配、教养、性欲求得分显著增高,情绪言语攻击欲求得分下降(P<001～005);2、神经症伴性障碍组的性生活质量低,性频度、性后快感均低.3、SDS、SAS与TAT中的负性欲求呈明显的相关性,性行为调查与婚姻质量量表中的性行为呈正相关.结论:神经症的性压抑与其潜在人格有密切的相关性.     

独生与非独生医学生卡特尔人格因素调查

随着时间的推移,独生子女在我国高校在校生中的比重逐年增加。本研究采用卡特尔16种个性因素量表,对独生子女与非独生子女的人格特征进行对比,以期了解独生子女个性的特异性。对象与方法1.1对象从河北北方学院2002级476名医学本科生中筛出独生子女共172人。采用1∶1配对设计。在独生子女所在的小班中确定同年龄、同性别,父母职业、家庭经济状况相近的172名非独生子女作为对照,172名独生子女中,男生90人,平均21.7±1.9岁;女生82人,平均22.0±1.5岁,男女间年龄差别无统计学意义(t=1.246,P=0.211)。1.2工具16项个性因素测量表(16PF)[1]。包括…     

CⅡTA M1-RNA对MHCⅡ类分子表达的抑制作用

目的探讨MHCⅡ类分子转录激活因子（CⅡTA）的M1-RNA对细胞表面MHCⅡ类分子表达的抑制。方法M1-RNA是核糖核酸酶P的催化活性单位，设计并克隆针对CⅡTA第452、629位点的M1-RNA（分别为M1-452-GS、M1-629-GS）及其相应的CⅡTA靶基因，分别插入pUC19、pGEM-7zf（＋）载体，进行细胞外切割活性筛选。将细胞外切割作甩明显的M1-629-GS亚克隆入psNAV载体（psNAV-M1-629-GS，pA629）并稳定转染ECV304细胞株，流式细胞术检测经典的MHCⅡ（HLA-DR、-DP、-DQ）类抗原表达，RT-PCR检测CⅡTA的mRNA水平。结果pA629阳性ECV304细胞株与对照组比较，HLA-DR、-DP抗原表达分别降低了89．21％及92．31％；同时CⅡTA的mRNA含量降低（P〈0．05）。结论CⅡTA的M1-RNA（M1-629-GS）降低了自身mRNA含量，从而阻止其调控的MHCⅡ类分子的表达。     

pEGFP-C3-B7.2-MAGE-1融合蛋白诱导特应性抗肿瘤免疫应答的研究

目的:构建重组表达载体pEGFP-C3-B7.2-MAGE-1,研究人B7.2/MAGE-1基因修饰的食管癌细胞作为瘤苗的抗肿瘤作用.方法:通过RT-PCR扩增B7.2和MAGE-1的cDNA,以pEGFP-C3为载体,构建pEGFP-C3-B7.2-MAGE-1重组载体,通过脂质体转染技术转染人食管癌细胞株EC9706,外周血来源的树突状细胞(DC)负载肿瘤抗原后,与自体T淋巴细胞共培养3天,获得细胞毒性T淋巴细胞(CTL),用四甲基偶氮唑蓝(MTT)法检测CTL对转染和未转染pEGFP-C3-B7.2-MAGE-1的食管癌细胞EC9706的杀伤活性.结果:CTL对转染pEGFP-C3-B7.2-MAGE-1的肿瘤细胞的杀伤活性大于转染pEGFP-C3和未转染细胞的杀伤活性(P＜0.05).结论:成功构建了真核共表达载体pEGFP-C3-B7.2-MAGE-1,人B7.2/MAGE-1基因修饰的EC9706肿瘤细胞瘤苗,可诱导出明显的抗EC9706细胞的免疫效应.     

FD-1冷冻干燥机的研制及生物材料的冷冻干燥

观察自制冷冻干燥机冷冻干燥生物材料的效果。采用 R5 0 2压缩机和制冷剂制成 FD- 1冷冻干燥机。本实验冷冻干燥了胶原海绵、菌种及去纤酶。在冻干箱负载或空载情况下蒸发冷凝器温度均可达到 - 4 5℃ ,小冰箱可达到 - 30℃ ,冻干的胶原海绵具有许多孔洞的结构 ,冻干的菌种和去纤酶性能保持良好。 FD- 1冷冻干燥机适用于生物样品中小批量的冷冻干燥