γ-Pyrone Compounds as Potential Anti-cancer Drugs

Abstract— The γ-pyrones, artomunoxanthotrione epoxide, cyclocommunol, cyclomulberrin, and cyclocommunin exhibited potent inhibition of human PLC/PRF/5 and KB cells in-vitro. Dihydroisocycloartomunin showed significant and potent inhibition of human PLC/PRF/5 and KB cells in-vitro, respectively. Cyclomorusin, dihydrocycloartomunin and artomunoxanthone showed significant inhibition of KB cells in-vitro. Based on the above finding and the reported antileukaemic activity of xanthone psorospermin, a series of natural γ-pyrones was prepared and the inhibition of human PLC/PRF/5 and KB cells in-vitro was measured. Structure-activity analysis indicated the epoxide group substituted at 3-hydroxyl and 2,6-; 3,6-; and 3,5-dihydroxyl xanthone enhanced the anti-tumour activity. The epoxide group substituted at the 6-hydroxyl group of 1,6-dihydroxyxanthone did not show anti-tumour activity.     

Pretreatment with Tongxinluo protects porcine myocardium from ischaemia/reperfusion injury through a nitric oxide related mechanism

Background The traditional Chinese medicine Tongxinluo can protect myocardium against ischaemia/reperfusion injury, but the mechanism of its action is not well documented. We examined the involvement of nitric oxide in the protective role of Tongxinluo. Methods Miniswine were randomized to four groups of seven: sham, control, Tongxinluo and Tongxinluo coadministration with a nitric oxide synthase inhibitor Nω-nitro-L-arginine (L-NNA, 10 mg/kg i.v.). Three hours after administration of Tongxinluo, the animals were anaesthetised and the left anterior descending coronary artery ligated and maintained in situ for 90 minutes followed by 3 hours of reperfusion before death. Area of no reflow and necrosis and risk region were determined pathologically by planimetry. The degree of neutrophil accumulation in myocardium was obtained by measuring myeloperoxidase activity and histological analysis. Myocardial endothelial nitric oxide synthase activity and vascular endothelial cadherin content were measured by colorimetric method and immunoblotting analysis respectively.Results Tongxinluo significantly increased the local blood flow and limited the infarct and size of no reflow. Tongxinluo also attenuated myeloperoxidase activity and neutrophil accumulation in histological sections and maintained the level of vascular endothelial cadherin and endothelial nitric oxide synthase activity in the reflow region when compared with control group. The protection of Tongxinluo was counteracted by coadministration with L-NNA. Conclusions Tongxinluo may limit myocardial ischaemia and protect the heart against reperfusion injury. Tongxinluo regulates synthesis of nitric oxide by altering activity of endothelial nitric oxide synthase.     

5 Gy全身照射对大鼠伤口巨噬细胞的抑制效应及W11-a12的促愈作用

目的 研究大鼠全身5Gy照射对伤口巨噬细胞（MΦ）功能的影响及W11－a12的促愈作用。方法 采用^60Coγ射线身身照射复合皮肤创伤模型,观察了MΦ酵母－补体复合物玫瑰花环形成试验、吞噬功能和分泌纤维粘连蛋白（FN）、转化生长因子β1（TGFβ1）、碱性成纤维细胞生长因子（bFGF）的功能。结果 大鼠5Gy全身照射复合皮肤创伤后第3、5天伤口内巨噬细胞C3b受体表达、吞噬功能,合成与分泌FN、TGFβ、bFGF的功能均显著受到抑制,但抑制效应的程度不同,MΦ的吞噬功能的抑制重于其分泌功能,分泌TGFβ1功能的抑制重于分泌bFGF的功能,W11-a12能显著逆转辐射对MΦ功能的抑制效应。结论 伤口MΦ功能受抑是合并放射损伤后伤口难愈的主要原因,增强MΦ功能是W11－a12促愈作用的一个途径。     

McAb共刺激PBLs淋巴细胞在培养体系中的状态及超微结构的 …

通过用抗ＣＤ３,ＣＤ２８＋ＣＤ８０ ＭｃＡｂ激活健康人的ＰＢＬｓ,并以ＰＨＡ,ＩＬ－２,ＰＢＬｓ为对照组;对各组不同时间段的淋巴细胞超微结构进行观察。结果提示：ＣＤ３及ＣＤ２８＋ＣＤ８０刺激淋巴细胞增殖外,也能使淋巴细胞活化,细胞表现为胞体增大,细胞器增多,具有粗大的绒毛和突出伪足,并可见单核细胞吞噬活跃。     

CT引导经皮肺穿刺锚状电极高温射频消融治疗肺部肿瘤105例

目的 观察ＣＴ引导经皮肺穿刺高温射频消融治疗１０５例肺部恶性肿瘤的近期效果。方法 ＣＴ引导经皮肺穿刺,可扩展锚状电极配合ＲＦ－２０００仪高温射频消融治疗原发性肺癌８１例,肺部转移瘤２４例,共计２４２个肿瘤,每个肿瘤治疗３～８次,持续时间３～３３７ｍｉｎ。结果 完全缓解（ＣＲ）率１１．１％,部分缓解（ＰＲ）率７１．１％,轻微疗效（ＭＲ）率１３．２％,无改变（ＮＣ）率４．５％,其中ＣＲ＋ＰＲ率为８２．     

Dose-Dependent Carcinogenicity and Frequent Ki-ras Proto-oncogene Activation by Dietary N-Nitrosodiethylamine in Rainbow Trout

While the experimental data upon which current concepts in mechanisticallybased risk assessment and molecular epidemiology are groundedderive almost entirely from rodent models, fish models haveseveral attributes (e.g., low background incidence, extremelylow cost tumor studies, nonmammalian comparative status forextrapolation of mechanisms to humans) that make them valuableadjuncts for addressing these concepts. This report providesan initial characterization of the dose dependency of dietaryN-nitrosodiethylamine (DEN) hepatocarcinogenicity in Shastastrain rainbow trout (Oncorhynchus mykiss) and the potentialof DEN to elicit ras proto-oncogene activation in this species.Carcinogen was administered in the diet at five concentrationsfor 12 months. Necropsies were per formed at 9, 12, and 18 months,the latter on fish maintained on control diet for 6 months aftercessation of DEN exposure. The incidence of hepatic neoplasmsat the lower dietary concentrations (70 ppm) did not consistentlyexceed that for control groups, which were higher in this particularstudy (2%) than expected (historically 0.1%). For the higherDEN concentrations, a linear relationship between the hepatictumor incidence (expressed as log odds, log [p/(1-p)1, wherep = proportion of fish bearing tumors), and the logarithm oftotal cumulative dose was observed, with response being independentof the length of time (9 or 12 months) during which the dosewas accumulated. The dose-response curve for fish maintainedan additional 6 months postexposure was shifted toward higherincidence but was parallel to the curve for fish killed at cessationof exposure. The model predicts that doubling the dose willproduce some what more than a doubling of the odds (pl(100 -p) for tumor incidence and that the odds for lesions 6 monthspostexposure will be approximately double those at cessationof exposure. Comparison of these results with previous studiesusing rats suggests an overall similarity in dose-response curves,with trout being somewhat less sensitive than rats to DEN hepatocarcinogenesis. To examine the molecular basis for DEN carcinogenesis in this species, seven liver tumors induced separatelyby short-term DEN treatment were probed by 3'-mismatch primerpolymerase chain reaction analysis for evidence of Ki-ras proto-oncogeneactivating point mutations. A very high proportion (6/7) oftumors was found to carry codon 12 GGA - AGA mutations, whereasno codon 61 mutants were detected in this sample. These initialresults differ from those reported using hepatic tumors fromDEN-treated mice, which exhibit frequent Ha-ras codon 61 mutations[Richardson et al., Carcinogenesis 13, 1277–1279 (1992)]and rats, which appear not to carry DEN-activated ras alleles[Bauer-Hoffman et al., Carcinogenesis 11, 1875–1877 (1990)].Thus the available oncogene data for the common carcinogen DENdo not suggest a simple, consistent oncogenic pathway or mutationalspectrum useful in the molecular epidemiology of human cancers.     

以零价铜为催化剂的“活性”可控自由基聚合反应

研究了零价铜为催化剂,以ＣＣｌ４为引发剂,在２,２’－邻二吡啶（ｂｐｙ）或１,１０－邻二氮菲（ｐｈｅｎ）存在下的苯乙烯或甲基丙烯酸甲酯的“活性”／可控自由基聚合反应。研究结果表明：聚合过程中ｌｎ（［Ｍ］ｏ／［Ｍ］）与反应时间成线性增长关系,同时生成的聚合物的数均分子量与单体转化率也成线性增长关系,聚合过程呈现“活性”特征。     

高压下滴流床反应器动持液量的测定

在常压－２．０ＭＰａ的系统压力下测定了滴流床中气－液两相并流下流动的动持液量,了气－液流率,液相粘度,填料大小,压力以及床层高度对动持液量的影响。实验结果表明增中液体流率动持流量增加,气体流率增加时,结果相反粘度的增加对动持液量的影响不大,动持液量随填料空隙率的增大而变小。     

轻、中度缺氧对事件相关电位的影响及不同刺激模式的比较

目的 观察轻、中度缺氧对脑事件相关电位（ＥＲＰ）的影响,比较不同刺激模式发的ＥＲＰ对缺氧的敏感性,方法１２名受试者在地面、２５００ｍ和４３００ｍ匠心同度（吸放低氧混合气）分别进行视觉Ｏｃｄｄｂａｌｌ、Ｓｔｅｒｎｂｅｒｇ记忆量（ＭＳＥＴ）为１ 和ＭＳＥＴ为３的任务测试,记录ＥＲＰ的Ｐ３潜伏期、波幅和反应时（ＲＴ）及反应错误率（ＥＲ）。结果 ４３００ｍ高度缺氧时Ｐ３潜伏期显著延长,任务难度较大时ＥＲ增