Akt/protein kinase B is constitutively active in non-small cell lung cancer cells and promotes cellular survival and resistance to chemotherapy and radiation

To evaluate the role of Akt/PKB in non-small cell lung cancer (NSCLC) survival, we analyzed NSCLC cell lines that differed in tumor histology as well as p53, Rb, and K-ras status. Constitutive Akt/protein kinase B (PKB) activity was demonstrated in 16 of 17 cell lines by maintenance of S473 phosphorylation with serum deprivation. Additional analysis of five of 2these NSCLC lines revealed that phosphorylation of S473 and T308 correlated with in vitro kinase activity. Akt/PKB activation was phosphatidylinositol 3-kinase-dependent and promoted survival because the phosphatidylinositol 3 inhibitors LY294002 and wortmannin inhibited Akt/PKB phosphorylation, Akt/PKB activity, and increased apoptosis only in cells with active Akt/PKB. To test whether Akt/PKB activity promoted therapeutic resistance, LY294002 was added with individual chemotherapeutic agents or irradiation. LY294002 greatly potentiated chemotherapy-induced apoptosis in cells with high Akt/PKB levels, but did not significantly increase chemotherapy-induced apoptosis in cells with low Akt/PKB levels. Combined with radiation in cells with active Akt/PKB, LY294002 additively increased apoptosis and inhibited clonogenic growth. These results were extended with transiently transfected Akt/PKB mutants. Transfecting dominant negative Akt/PKB decreased Akt/PKB activity and increased basal apoptosis as well as chemotherapy- and irradiation-induced apoptosis only in cells with high Akt/PKB activity. Conversely, transfecting constitutively active Akt/PKB into cells with low Akt/PKB activity increased Akt/PKB activity and attenuated chemotherapy- and radiation-induced apoptosis. We therefore identify Akt/PKB as a constitutively active kinase that promotes survival of NSCLC cells and demonstrate that modulation of Akt/PKB activity by pharmacological or genetic approaches alters the cellular responsiveness to therapeutic modalities typically used to treat patients with NSCLC.     

HIV-1 Tat neurotoxicity is prevented by matrix metalloproteinase inhibitors

The release of potentially neurotoxic molecules by HIV-infected brain macrophages is accompanied by neuronal injury and death that results in the development of HIV-associated dementia (HAD). Among the potential neurotoxins implicated in the development of HAD is the HIV-1 transactivating protein, Tat. To investigate the mechanism by which Tat causes neurotoxicity, brain-derived Tat sequences from nondemented (Tat-ND) and demented (Tat-HAD) AIDS patients, which differed primarily in the augmenting region of Tat, were expressed in U937 monoblastoid cells and primary human macrophages. Cells expressing Tat-HAD protein exhibited elevated matrix metalloproteinase (MMP)-2 and -7 release and activation, but cells expressing Tat-ND did not exhibit enhanced MMP expression. Conditioned media from Tat-HAD-transfected cells caused significantly greater neuronal death (15.4 +/- 4.3%) than did Tat-ND (4.4 +/- 2.1%) or nontransfected (2.1 +/- 0.8%) cell-derived conditioned media. The neurotoxicity induced by Tat-HAD was inhibited by anti-MMP-2 or -7 antibodies (p < 0.005) but not by antibodies against MMP-9 or Tat. Similarly, scid/nod mice receiving striatal implants of Tat-HAD-transfected cells exhibited greater neurobehavioral abnormalities and neuronal loss (p < 0.005) than did animals receiving Tat-ND or nontransfected cells, which were reduced by treatment with the MMP inhibitor prinomastat (p < 0.005). These findings indicate that Tat causes neuronal death through an indirect mechanism that is Tat sequence dependent and involves the induction of MMPs.     

Effect of severe aortic banding above the renal arteries on nitric oxide synthase isotype expression

BACKGROUND: Severe aortic stenosis above the renal arteries leads to a reduction in renal perfusion, increased renin secretion, and elevation of arterial blood pressure above the stenotic site. Nitric oxide (NO) plays an important role in regulation of renal and systemic vascular resistance, renal blood flow, and Na(+) handling. Abdominal aortic banding provides an excellent model for simultaneous testing of the effects of increased and decreased pressure, flow, and shear stress in the same animal. METHODS: We studied protein expressions of endothelial NO synthase (eNOS), inducible NOS (iNOS), and neuroneal NOS (nNOS) isotypes in the renal cortex, renal medulla, heart, brain, and aorta segments above and below the stenosis site three weeks after abdominal aortic banding above the renal arteries. The results were compared with those obtained in the sham-operated controls. NOS isotype proteins were measured by Western blot. RESULTS: Compared with the control group, the banded group showed significant up-regulations of eNOS, iNOS, and nNOS in renal cortex and medulla. Likewise, heart eNOS, brain nNOS, and thoracic aorta eNOS proteins were significantly increased in the banded group. However, eNOS and iNOS expressions were unchanged in the aorta segment below the stenotic site. Likewise, iNOS expression in the heart and thoracic aorta remained unchanged in the banded animals. No significant difference was found in creatinine clearance or urinary protein excretion between the two groups. CONCLUSIONS: These findings clearly demonstrate the up-regulatory action of increased pressure on eNOS expression in the thoracic aorta and heart and of nNOS expression in the brain. These data further show up-regulation of all NOS isotypes in the kidney, which must have helped to mitigate the associated hypoperfusion.     

米非司酮不同服用方法对皮下埋植术后子宫出血影响的观察

目的:探讨米非司酮不同服用方法对皮下埋植避孕术后子宫异常出血的影响。方法:120例行皮下埋植避孕术妇女随机分为3组,每组40例。对照组不服用任何药物;一日组在埋植日和每月月经来潮当日服米非司酮50mg,共服6次;两日组在埋植日和每月月经来潮当日、次日各服米非司酮25mg,共服6次。结果:服用米非司酮期间出血天数和滴血天数较对照组减少(P<0.01),经期延长和长期不规则出血百分率低于对照组(P<0.05),但一日组和两日组间差异无显著意义(P>0.05)。停药后组出血天数较对照组明显减少(P<0.05)、滴血天数差异无显著性意义(P>0.05),一日组和两日组间差异无显著性意义(P>0.05)。结论:皮下埋植术后单次服用米非司酮可以改善术后子宫异常出血。     

慢性非传染性疾病综合防治的进展

现阶段我国慢性非传染性疾病发病率、死亡率逐渐增高,日益成为威胁人民健康的主要疾病,自"七.五"期间在北京、上海、天津等省市开展以心血管疾病、脑卒中为主的综合防治干预研究以来,防控工作取得了较好的社会效果,而且有效提高了社区人群的健康知识水平,改善了不良生活方式.阐述了近10 a慢性非传染性疾病综合防治方面的进展情况.     

血清CagA抗体鉴定幽门螺杆菌高毒株感染的评价

目的 评价通过检测血清CagA抗体鉴定幽门螺杆菌高毒株感染的可行性.方法 采集福州地区临床门诊行胃镜检查的胃活检标本,行病理检查和幽门螺杆菌(Hp)培养;采集病人血清,PCR法检测分离所得的Hp cagA基因;EIA法测定血清CagA抗体,分析cagA基因的检出与消化性疾病的关系,比较CagA基因与CagA抗体的检测结果,评价应用CagA抗体检测Hp高毒株感染的可行性.结果 分离获得80株Hp,其中54株检出cagA基因,阳性率67.50%.各病理类型胃病患者cagA基因阳性率:浅表性胃炎77.42%,萎缩性胃炎62.86%,胃溃疡58.33%,胃癌50.00%,各组间差别无统计学意义(P＞0.05);CagA抗体阳性率55.00%,敏感度74.07%,特异度84.62%,约登指数58.69%,调整一致性77.68%.结论 检测血清CagA抗体用于诊断高毒力Hp感染存在局限性.     

群体创伤在基层医院急诊室的抢救护理

目的总结群体创伤在基层医院急诊室的抢救护理经验。方法对三起道路交通事故79例创伤病人的抢救护理进行回顾性分析。结果所有病例均在抵达急诊室15min～60min内完成初步的抢救或处理,然后分别送入手术室和病房进一步治疗,总抢救成功率96.2%。结论基层医院急诊室对群体创伤的抢救护理要达到高效、有序,就必须加强急诊室护士的培训,设置合理的抢救预案,建立完善的应急系统。