非小细胞肺癌组织中VEGF-C和VEGFR-3的表达及其临床意义

背景与目的:血管内皮生长因子-C(vascularendothelialgrowthfactorC,VEGF-C)和VEGFR-3是促进恶性肿瘤淋巴管形成的重要因子,其表达与恶性肿瘤的淋巴结转移关系密切。本文旨在研究VEGF-C和VEGFR-3蛋白在非小细胞肺癌(non-smallcelllungcancer,NSCLC)组织中的表达及其临床意义。方法:应用免疫组化方法检测77例NSCLC组织中VEGF-C和VEGFR-3表达情况,分析其与肿瘤淋巴管密度(lymphaticvesseldensity,LVD)、肿瘤的大小、癌的组织类型、组织分化程度、淋巴结转移情况、临床复发和术后生存期的关系。结果:77例NSCLC组织中有45例(58%)VEGF-C阳性,32例(42%)VEGFR-3阳性。NSCLC组织中VEGF-C表达与肿瘤组织的分化程度有关(r=-0.32,P=0.018);VEGF-C及VEGFR-3表达与肿瘤的淋巴结转移、LVD、肿瘤大小及术后生存期有关。NSCLC组织中VEGF-C与VEGFR-3表达相关(r=0.23,P=0.045)。结论:VEGF-C和VEGFR-3表达与NSCLC的淋巴结转移、预后相关,它的高表达提示肺癌患者容易出现淋巴结转移和预后不良。     

Olanzapine increases in vivo dopamine and norepinephrine release in rat prefrontal cortex, nucleus accumbens and striatum

The in vivo effects of olanzapine on the extracellular monoamine levels in rat prefrontal cortex (Pfc), nucleus accumbens (Acb) and striatum (Cpu) were investigated by means of microdialysis. Sequential doses of olanzapine at 0.5, 3 and 10 mg/kg (SC) dose-dependently increased the extracellular dopamine (DA) and norepinephrine (NE) levels in all three brain areas. The increases appeared 30 min after olanzapine administration, reached peaks around 60–90 min and lasted for at least 2 h. The highest DA increases in the Acb and Cpu were induced by olanzapine at 3 mg/kg but at 10 mg/kg in the Pfc. The peak DA increase in the Pfc (421% ± 46 of the baseline) was significantly larger than those in the Acb (287% ± 24) and Cpu (278% ± 28). Similarly, the highest NE increase in the Pfc (414%±40) induced by 10 mg/kg olanzapine was larger than those in the Acb (233% ± 39) and Cpu (223% ± 24). The DA and NE increases in the Pfc induced by olanzapine at 3 and 10 mg/kg (SC) were slightly larger than those induced by clozapine at the same doses. In contrast, haloperidol (0.5 and 2 mg/kg, SC) did not change Pfc DA and NE levels. Extracellular levels of a DA metabolite, DOPAC, and tissue concentrations of a released DA metabolite, 3-methoxytyramine, were also increased by olanzapine, consistent with enhanced DA release. However, olanzapine at the three sequential doses did not alter the extracellular levels of either 5-HT or its metabolite, 5-HIAA, in any of the three brain areas. In conclusion, the present studies demonstrate that in the case of sequential dosing olanzapine more effectively enhances DA and NE release in the Pfc than in the subcortical areas, which may have an impact on its atypical antipsychotic actions. Received: 7 May 1997/Final version: 15 September 1997     

Nitric oxide is a preconditioning mimetic and cardioprotectant and is the basis of many available infarct-sparing strategies

Ischemic preconditioning is a powerful infarct-sparing intervention. Intensive investigations have revealed many of the signaling steps used to elicit this protection. One of the steps involves activation of nitric oxide synthase (NOS) by phosphorylation, with the production of NO and subsequent activation of guanylyl cyclase, production of cGMP, activation of protein kinase G, opening of mitochondrial KATP channels, and generation of reactive oxygen species. The latter act as second messengers to activate critical kinase cascades that trigger entrance into the preconditioned state. Thus, NO exposure before ischemia can act as a powerful preconditioning mimetic. Elevating NO just prior to or at reperfusion can still be an effective cardioprotective strategy. Activation of NOS or production of NO can be done pharmacologically with exogenous agents to trigger this cascade. Many of these strategies are already available and safe.     

Cardioprotection by mild hypothermia during ischemia involves preservation of ERK activity

Cooling the ischemic heart by just a few degrees protects it from infarction without affecting its mechanical function, but the mechanism of this protection is unknown. We investigated whether signal transduction pathways might be involved in the anti-infarct effect of mild hypothermia (35°C). Isolated rabbit hearts underwent 30 min of coronary artery occlusion/2 h of reperfusion. They were either maintained at 38.5°C or cooled to 35°C just before and only during ischemia. Infarct size was measured. The effects of the protein kinase C inhibitor chelerythrine, the nitric oxide synthase inhibitor N (ω)-nitro-L: -arginine methyl ester (L: -NAME), the phosphatidylinositol 3-kinase antagonist wortmannin, or either of the mitogen-activated protein kinase kinase 1/2 (MEK1/2) inhibitors PD98059 or U0126 on cooling's protection were examined. Myocardial ATP assays were performed and the level of phosphorylation of extracellular signal-regulated kinase (ERK) and MEK was examined by western blotting. To investigate an effect of cooling on protein phosphatase (PPase), a PPase inhibitor cantharidin was tested in the infarct model and the effect of mild hypothermia on PP2A activity in vitro was measured. Infarct size was 34.4 ± 2.2% of the ischemic zone in normothermic (38.5°C) hearts, but only 15.6 ± 8.7% in hearts cooled to 35°C during ischemia. Mechanical function was unaffected. Neither chelerythrine, L: -NAME, nor wortmannin had any effect, but both PD98059 and U0126 completely eliminated protection. Ischemia rather than reperfusion was the critical time when ERK had to be active to realize protection. Phosphorylation of ERK and MEK fell during normothermic ischemia, but during hypothermic ischemia phosphorylation of ERK remained high while that of MEK was increased. Cooling only slightly delayed the rate at which ATP fell during ischemia, and ERK inhibition did not affect that attenuation suggesting ATP preservation was unrelated to protection. Cantharidin, like cooling, also protected during ischemia but not at reperfusion, and its protection was dependent on ERK phosphorylation. However, mild hypothermia had a negligible effect on PP2A activity in an in vitro assay. Hence, mild hypothermia preserves ERK and MEK activity during ischemia which somehow protects the heart. While a PPase inhibitor mimicked cooling's protection, a direct effect of cooling on PP2A could not be demonstrated.     

人皮肤纤维母细胞高密度脂蛋白的受体的研究

本实验用正常人血清HDL_3与体外培养的正常人皮肤纤维母细胞进行了受体结合实验,并研究了HDL_3清除细胞内胆固醇(Ch)的作用。结果表明,人皮肤纤维母细胞上有不同于LDL受体的HDL受体。此受体不受钙离子及胰蛋白酶的影响;用Ch孵育细胞可使细胞结合~(125)I-HDL_3的量明显增加(P<0.05),而用无脂蛋白血清(LPDS)孵育细胞则可减少细胞结合~(125)I-HDL_3的量(P<0.05),这些说明HDL受体受细胞内Ch含量的调节。HDL_3清除细胞内Ch的浓度效应曲线与细胞特异性结合HDL_3的浓度效应曲线相似,均为可饱和图形;亚胺环已酮可使HDL_3清除细胞Ch的能力有所下降,提示人皮肤纤维母细胞上HDL受体与HDL_3清除细胞Ch的功能有关。     

Characterization of a novel cellular defect in patients with phenotypic homozygous familial hypercholesterolemia

Familial hypercholesterolemia (FH) is characterized by a raised concentration of LDL in plasma that results in a significantly increased risk of premature atherosclerosis. In FH, impaired removal of LDL from the circulation results from inherited mutations in the LDL receptor gene or, more rarely, in the gene for apo B, the ligand for the LDL receptor. We have identified two unrelated clinically homozygous FH patients whose cells exhibit no measurable degradation of LDL in culture. Extensive analysis of DNA and mRNA revealed no defect in the LDL receptor, and alleles of the LDL receptor or apo B genes do not cosegregate with hypercholesterolemia in these families. FACS((R)) analysis of binding and uptake of fluorescent LDL or anti-LDL receptor antibodies showed that LDL receptors are on the cell surface and bind LDL normally, but fail to be internalized, suggesting that some component of endocytosis through clathrin-coated pits is defective. Internalization of the transferrin receptor occurs normally, suggesting that the defective gene product may interact specifically with the LDL receptor internalization signal. Identification of the defective gene will aid genetic diagnosis of other hypercholesterolemic patients and elucidate the mechanism by which LDL receptors are internalized.     

Utility of Tissue Similarity Maps Based on Relative Cerebral Blood Volume for Grading Gliomas as Validated by Histological Results

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