Lung cancer risk in iron and steel foundry workers: a nested case control study in Asturias, Spain

BACKGROUND: Workers of iron and steel foundries have a high lung cancer risk but the findings on specific processes associated with this risk are inconsistent. We examined the risk of lung cancer among workers in the main industrial processes of a large iron and steel foundry in Asturias, Spain. METHODS: We conducted a nested case-control study comprised of 144 male lung cancer cases and 558 controls, selected from a study base of about 24,400 workers employed in the industry between 1952 and 1995. Cases were identified through linkage of industry records with those of two cancer registries. Controls were selected through industry records using incidence density sampling, were matched to cases by age and date of birth and had to be alive and without lung cancer at the time of selection. Smoking history was obtained through company medical records. Unconditional logistic regression was applied and all ORs were adjusted for age and tobacco consumption. RESULTS: Workers were, on an average, heavy smokers and a very strong relation was observed for smoking (OR for "ever smoker" = 32.4). Workers having ever been employed in the blast furnace had an excess lung cancer risk (OR = 2.55, 95% CI 1.25-5.21) compared to a reference group of workers not employed in metal producing departments. A similar excess was observed for workers having as their longest held job employment in the blast furnace. A two-fold risk was also observed for workers in the main foundry. For subgroups of workers, tobacco smoking appeared to be an important positive or negative confounder. CONCLUSIONS: In this large Spanish foundry, a high risk was observed for workers employed in departments with high exposure to crystalline silica, PAHs, and various other carcinogenic chemicals. Although comparisons were made between workers of the same industry, smoking habits differed and adjustment by smoking modified considerably the risk estimates.     

解放思想开拓创新继续推进卫生改革与发展

指出卫生工作要以“三个代表”重要思想为指导,紧扣改革与发展的总目标;要按照“三个代表”的要求,加快卫生体制的改革与创新,要明确政府卫生职责,转变职能,实现“政事分开”,建立符合社会主义市场经济规律和人民健康需求的卫生服务体系,建立权责明晰、富有生机的医疗机构管理体制;要全面引入竞争机制,加快医疗机构运行机制的改革与创新,继续推进病人选医院和选医生,调动医疗机构内在的动力和广大医务人员的积极性,发展多样化、多种形式办医模式,形成公平、有序的竞争局面。     

转变作风真抓实干做好2002年重点卫生工作

根据中共中央、国务院要求,结合卫生工作实际提出卫生部2002年的重点工作是:认真贯彻落实农村卫生改革与发展的指导意见,加快配套文件出台,探索和实行多种形式农民健康保障办法;继续深化城镇医药卫生体制改革,加强医疗服务质量管理,推进医疗机构属地化管理,发展多种形式办医模式,推进社区卫生服务;继续加强重大疾病控制,尤其是艾滋病、结核病、乙型肝炎、血吸病和地方病的预防控制,加强疾病监测和建设,防范生化恐怖活动;进一步依法行政,加大综合执法力度;加强精神文明建设,全面推进各项卫生工作。     

Synergistic interaction between vinorelbine and gamma-linolenic acid in breast cancer cells

It has been suggested that exogenous unsaturated fatty acids (UFAs) may increase the cytotoxic activity of cancer chemotherapeutic agents. We examined how γ-linolenic acid (GLA; 18 : 3n-6), the most promising UFA in the treatment of human tumors, affects the effectiveness of the lipophilic drug vinorelbine (VNR) on human breast carcinoma cell lines. Cells were exposed simultaneously to VNR and GLA or sequentially to GLA followed by VNR. Cell viability was determined by MTT assay. The increase in VNR-induced cell growth inhibition was measured by dividing the IC₅₀ and IC₇₀ values (50 and 70% inhibitory concentrations, respectively) that were obtained when the cells were exposed to VNR alone with those with VNR plus GLA. We found that GLA enhanced in a dose-dependent manner the cell growth inhibitory activity of VNR on MCF-7 cells (up to 9-fold). As GLA by itself showed anti-proliferative effects, possible GLA-VNR interactions at the cellular level were assessed employing the isobologram analysis and the combination index (CI) method of Chou–Talalay. Both methods showed an overall synergism between GLA and VNR in MCF-7 cells. At a high level of cell kill, the synergism was greater when a 24 h GLA pre-exposure or co-exposures were tested. Synergy was likewise observed with the GLA-VNR combination in MDA-MB-231, T47D, and SK-Br3 breast cancer cells. In all cell lines, the synergism was independent of the treatment schedule and the exposure time. Under conditions inhibiting lipid peroxidation using Vitamin E (dl-α-tocopherol), the enhancing effect of GLA (an easily oxidizable UFA) on VNR activity was partially abolished. However, when Vitamin E was used in combination, a similar synergistic increase in growth inhibition was obtained. These latter observations strongly implies that the synergistic effects of GLA with VNR are not mediated through a mechanism involving a generation of lipoperoxides. For comparison, the effects of other UFAs were examined on VNR chemosensitivity: GLA was the most potent at enhancing VNR activity, followed by docosahexaenoic acid (22 : 6n-3), eicosapentaenoic acid (20 : 5n-3) and α-linolenic acid (18 : 3n-3), whereas linoleic acid (18 : 2n-6) and arachidonic acid (20 : 4n-6) did not increase VNR chemosensitivity. Very high concentrations of oleic acid (OA; 18 : 1n-9), an UFA inversely correlated with breast cancer risk, also enhanced VNR effectiveness. Thus, various types of UFAs were not equivalent with respect to their actions on VNR effectiveness. In conclusion, our results give experimental support to the hypothesis that some UFAs can be used as modulators of tumor cell chemosensitivity and provide the rationale for in vivo preclinical investigation.     

普卢利沙星片的健康人体药动学

目的 健康志愿受试者口服普卢利沙星片后,测定血浆中其活性代谢物(UFX)并作药动学研究。方法 10名受试者分别单剂量和多剂量稳态时服用普卢利沙星片(相当于200 mg UFX),采集血浆和尿液样品,液相色谱分离荧光检测UFX浓度,3P97软件计算药动学参数。结果 单剂量时测得UFX的主要药动学参数分别为c_max(1.64±0.29)μg·ml^-1,t_max(0.7±0.2)h,AUC_0-36(6.87±1.78)h·μg·ml^-1,AUC_0-∞(7.14±1.79)h·μg·ml^-1,t_1/2(7.54±0.59)h,MRT(8.76±0.65)h;0～36 h尿液累积排泄量为(56.85±9.12)%。稳态时测得UFX的主要药动学参数分别为c_max(1.26±0.41)μg·ml^-1,t_max(0.8±0.3)h,AUC_0-36(7.77±2.73)h·μg·ml^-1,AUC_0-∞(8.10±2.70)h·μg·ml^-1,t_1/2(7.71±1.13)h,MRT(9.85±1.40)h。结论 健康志愿受试者口服普卢利沙星片后,在体内转化为活性代谢物(UFX)发挥作用,主要经尿液排泄。每日2次,每次2片(相当于200mg UFX),在体内无积蓄。男女健康受试者的主要药动学参数无显著性差异。