Dietary fat and breast cancer risk: The feasibility of a clinical trial of breast cancer prevention

Animal experimental evidence and human ecological data suggest that dietary fat intake is related to breast cancer risk. Epidemiological studies within countries have given inconsistent results but are limited by the restricted range of dietary intake found in Western populations and by error in the measurement of fat consumption. Experimental evidence, derived from controlled clinical trials in which the range of fat intake is increased beyond that seen in most Western populations, is capable of overcoming this limitation of observational epidemiology, and would provide the strongest evidence available concerning the relationship of dietary fat intake to breast cancer risk. Further, such trials are the only means likely to answer the question of whether breast cancer risk in high-risk subjects can be modified by changing dietary fat intake. We describe here several aspects of the feasibility of an experimental approach to this problem, including the identification of subjects at increased risk for breast cancer, and the demonstration that such subjects will enter a clinical trial of dietary fat reduction and comply with a low-fat diet. It is shown that subjects can be recruited and retained in such trials, that satisfactory dietary compliance can be achieved over at least 24 mon and that the subjects selected are at demonstrably increased risk of breast cancer. This finding indicates that it is feasible to test the dietary fat-breast cancer hypothesis experimentally by means of a clinical trial. Based on a paper presented at the Symposium on Lipids in Cancer held at the AOCS Annual Meeting, Baltimore, MD, April 1990.     

化妆品标签相关的“职业索赔”风险防范

在化妆品职业打假领域,因标签标识问题导致的索赔纠纷占据了相当大的比例。针对化妆品标签可能出现的不规范标注,分析探讨了化妆品生产者、经营者在审核标签中产品名称、责任人、成分表、保质期、警示语等信息时需要注意的事项。面对日益严峻的职业索赔挑战,企业除了从内部加强标签审核,还可将标签交由第三方机构进行检验,双管齐下加强风险防范和应对的能力。     

The use of bacteriophages for treatment and prevention of bacterial disease in animals and animal models of human infection

A brief history of the use of lytic bacteriophages in bacterial disease therapy is presented. After early disillusionment with the idea following poor experimental work, control of phages and field trials, studies were set up in the 1980's in the UK to study their use in farm animal infections. Work with E. coli septicaemia and diarrhoea has shown that phages can be highly effective prophylactically and therapeutically and more effective than antibiotics. There is considerable potential for their use in a limited number of infection types in both man and animals. © 2001 Society of Chemical Industry     

环境中有害因素对食品的影响及预防检验机制

本文讨论了环境中有害因素对食品的影响及预防检验机制,提出了质监系统、广大人民群众以及政府在食品安全中的重要作用,特别强调针对来源与特点开展食品中污染物的预防检验机制.     

Study of factors related to performance improvement of self-healing epoxy based on dual encapsulated healant

Our earlier work developed epoxy based self-healing composites with embedded dual microcapsules, which contain unreacted epoxy as the polymerizable component and mercaptan and tertiary amine catalyst as the hardener, respectively. Self-healing was allowed to proceed rapidly, offering attractive repair effectiveness. To give full play to the healing agent, influences of a series of factors on healing chemistry of the composites were studied in this paper. It was found that strong alkality of the catalyst, high activity of mercaptan, and low viscosity of the encapsulated epoxy prepolymer ensured high healing efficiency and rate of healing. In addition, matching of the microcapsules' sizes and fractions was critical for keeping stoichiometric ratio of the components at the damage areas, as required by the mechanism of the healing reaction (i.e. addition polymerization). Homogeneous dispersion of the capsules under proper stirring speed led to timely contacts between the healant fluids flowing out of the fractured capsules. Larger microcapsules favored filling of the cracks in terms of larger amount of the released healing agent, while smaller ones facilitated mixing and interdiffusion of the ingredients. The results provided key data for optimizing the self-healing system.     

Prognosis of breast cancer is associated with one-carbon metabolism related nutrients among Korean women

ABSTRACT: BACKGROUND: The 5-year survival rate for breast cancer among Korean women has increased steadily; however, breast cancer remains the leading cause of cancer mortality among women. One-carbon metabolism, which requires an adequate supply of methyl group donors and B vitamins, may affect the prognosis of breast cancer. This aim of this study was to investigate the associations of dietary intake of vitamin B2, vitamin B6 and folate before diagnosis on the prognosis of breast cancer. METHODS: We assessed the dietary intake using a food frequency questionnaire with 980 women who were newly diagnosed and histopathologically confirmed to have primary breast cancer from hospitals in Korea, and 141 disease progression events occurred. Cox's proportional hazard regression models were used to estimate the hazard ratio (HR) and 95% confidence interval (95% CI) adjusting for age, education, recruitment sites, TNM stage, hormone status, nuclear grade and total calorie. RESULTS: There was no significant association between any one-carbon metabolism related nutrients (vitamin B2, B6 and folate) and the progression of breast cancer overall. However, one-carbon metabolism related nutrients were associated with disease progression in breast cancer patients stratified by subtypes. In ER + and/or PR + breast cancers, no association was observed; however, in ER--/PR-- breast cancers, a high intake of vitamin B2 and folate statistically elevated the HR of breast cancer progression (HR = 2.28; 95% CI, 1.20-4.35, HR = 1.84; 95% CI, 1.02-3.32, respectively) compared to a low intake. This positive association between the ER/PR status and progression of the disease was profound when the nutrient intakes were categorized in a combined score (Pinteraction = 0.018). In ER--/PR-- breast cancers, high combined scores were associated with a significantly poor DFS compared to those belonging to the low score group (HR = 3.84; 95% CI, 1.70-8.71). CONCLUSIONS: In conclusion, our results suggest that one-carbon related nutrients have a role in the prognosis of breast cancer depending on the ER/PR status.     

二氧化氯稳定性相关基本性质及影响因素综述

二氧化氯作为一种广谱、高效消毒剂已得到广泛应用。但是,其自身活泼的性质难以制备成稳定制剂,对应用推广造成了限制。综述了二氧化氯稳定相关的基本化学性质以及pH、光、温度及其他共存物质的影响。指出二氧化氯无法在水中稳定存在,只能通过调整环境条件减缓分解、歧化过程,也可以利用平衡原理保持浓度稳定。此为高纯即用稳定二氧化氯的产品开发提供理论依据。在此基础上,应进一步进行二氧化氯转化的动力学研究,或尝试络合等方法提高二氧化氯相关产品的稳定性。     

Factors related to birth weight: a comparison of related factors between newborns of Spanish and Colombian immigrant women in Spain

The objective of this study is to establish differentials in birth weight (BW) and related factors, in term newborns (NB) of Spanish (SP) and Colombian (CO) immigrant mothers living in Spain, between 2001-2005. Data on the NB population of SP and CO mothers was retrieved from the National Statistical Bulletin of Birth in Spain. We analysed the association with BW (Low birth weight -LBW- insufficient weight -IW- macrosomia), by the nationality of the mother; taking into account variables such as the intergenesic interval, maternal age, number of live children, maternal occupation and sex of NB. The analysis was based on frequencies and the estimation of simple and adjusted odds ratios (OR) by means of logistic regression with 95% confidence intervals (95% CI). A higher prevalence of LBW was found in SP mothers (3.4%) than in their CO counterparts (2.1%). In SP mothers a higher risk of LBW (aOR 1.89, 950% CI 1.65- 2.16) and IW (aOR 1.49, 95% CI 1.51- 1.57) was observed. In CO mothers a higher percentage of macrosomia was found (8.0%). Also, a higher percentage of LBW was observed in female new borns (SP4.1%; CO 2.7%) as well as IW (PI (SP 25.6%; CO 19.6%) (p < 0.001). Mothers aged > 40 years and having 4 or more children were associated with LBW in both nationalities. As a conclusion, NB of Colombian mothers presented a lower prevalence of LBW and IW, which could be explained by the healthy migrant effect.     

PI3K/AKT信号在增强乳腺癌细胞对肿瘤坏死因子相关凋亡诱导配体敏感性中的作用及其机制

目的分析磷脂酰肌醇3激酶(phosphatidylinositol 3 kinase,PI3K)/蛋白激酶B(protein kinase B,AKT)通路是否通过长细胞caspase-8样抑制蛋白(cellular FLICE inhibitory protein,c-FLIP-L)的介导来影响乳腺癌细胞对肿瘤坏死因子相关凋亡诱导配体(TNF related apoptosis inducing ligand,TRAIL)的敏感性,并探讨其机制。方法用40 nmol/L wortmannin(AKT活化的特异性抑制剂)、100 ng/ml TRAIL、40 nmol/L wortmannin+100 ng/ml TRAIL处理人乳腺癌MDA-MB-231细胞,并设空白对照组。MTT法检测药物作用24、48、72 h后的细胞增殖抑制率;流式细胞术检测药物作用48 h后的细胞凋亡率;Western blot法检测细胞中磷酸化AKT(pAKT)和c-FLIP-L的表达。结果TRAIL+wortmannin组24、48和72 h细胞增殖抑制率与其他组比较,均明显升高(P0.05);TRAIL+wortmannin组与TRAIL组和wortmannin组比较,可明显促进细胞凋亡(P0.05);随着wortmannin作用时间的延长,pAKT的表达水平明显降低,同时c-FLIP-L的表达水平也随之下降,而TRAIL对pAKT和c-FLIP-L的表达无明显影响。结论抑制PI3K/AKT通路可增强乳腺癌细胞对TRAIL的敏感性,这种作用可能是通过c-FLIP-L的介导来实现的。     

含CO_2采油井油管腐蚀影响因素及防治措施研究

西部S油田含CO_2采油井油管腐蚀问题严重,通过室内模拟试验,采用高温高压动态腐蚀反应釜模拟井筒动态腐蚀环境,考察了采出液含水率、温度、CO_2分压、矿化度和流体流速对油管钢材腐蚀速率的影响,并优选出了一种性能优良的抗CO_2缓蚀剂RYH-301,评价了其对目标油田采油井油管钢的防腐蚀效果。结果表明:随着采出液含水率、温度、CO_2分压、矿化度以及流速的增大,油管钢材的腐蚀速率均呈现出逐渐增大的趋势;抗CO_2缓蚀剂RYH-301能够对目标油田采油井油管钢材起到较好的防护作用,当其质量浓度为150 mg/L时,缓蚀率可达98%以上。     

Polo样蛋白激酶1与乳腺癌发生、发展及治疗的相关性

乳腺癌是女性最常见的恶性肿瘤之一,发病率高,极易复发和转移,且具有年轻化趋势,靶向治疗已成为乳腺癌治疗的趋势和研究热点。Polo样蛋白激酶1(Polo-like kinase 1,Plk1)是一种广泛存在于真核生物中的丝氨酸/苏氨酸蛋白激酶,在人类多数肿瘤中表达水平较高,近年来被认为是治疗恶性肿瘤的干预靶点,靶向Plk1的乳腺癌治疗已成为近年来关注的热点。本文对Plk1与乳腺癌发生、发展及转移的相关性,以及目前靶向Plk1的乳腺癌治疗策略进行综述。     

The effect of walnut intake on factors related to prostate and vascular health in older men

Background

Tocopherols may protect against prostate cancer and cardiovascular disease (CVD).

Methods

We assessed the effect of walnuts, which are rich in tocopherols, on markers of prostate and vascular health in men at risk for prostate cancer. We conducted an 8-week walnut supplement study to examine effects of walnuts on serum tocopherols and prostate specific antigen (PSA). Subjects (n = 21) consumed (in random order) their usual diet +/- a walnut supplement (75 g/d) that was isocalorically incorporated in their habitual diets. Prior to the supplement study, 5 fasted subjects participated in an acute timecourse experiment and had blood taken at baseline and 1, 2, 4, and 8 h after consuming walnuts (75 g).

Results

During the timecourse experiment, triglycerides peaked at 4 h, and gamma-tocopherol (γ-T) increased from 4 to 8 h. Triglyceride – normalized γ-T was two-fold higher (P = 0.01) after 8 versus 4 h. In the supplement study, change from baseline was +0.83 ± 0.52 μmol/L for γ-T, -2.65 ± 1.30 μmol/L for alpha-tocopherol (α-T) and -3.49 ± 1.99 for the tocopherol ratio (α-T: γ-T). A linear mixed model showed that, although PSA did not change, the ratio of free PSA:total PSA increased and approached significance (P = 0.07). The α-T: γ-T ratio decreased significantly (P = 0.01), partly reflecting an increase in serum γ-T, which approached significance (P = 0.08).

Conclusion

The significant decrease in the α-T: γ-T ratio with an increase in serum γ-T and a trend towards an increase in the ratio of free PSA:total PSA following the 8-week supplement study suggest that walnuts may improve biomarkers of prostate and vascular status.     

DDVP微胶囊的研制及其性能的影响因素

本文主要介绍了一种制备DDVP微胶囊制剂的方法,分析多种反应条件对DDVP微胶囊制剂性能的影响,实验结果表明,选用聚甲基丙烯酸甲酯为囊皮材料,温度在45℃,pH值控制在4.0～4.2之间,可制得适合的DDVP微胶囊制剂.     

Space-filling models for coal. 2. Extension to coals of various ranks

Space-filling models of scale 10⁸:1 have been constructed for low-, intermediate-, and high-rank coal molecules. The molecules have been designed to conform to experimentally determined parameters, such as chemical composition, aromaticity and ring index. The molecules do not actually occur in nature, but are merely statistically-averaged structures. The low-rank coal species appears fluffy, porous and random, with essentially all interior atoms exposed as surface. The intermediate-rank coal model structure is more flat and oriented, with closed ended pores and only occasional non-coplanar protrusions due to aliphatic, alicyclic, and hydroaromatic moeities. The high-rank coal model is highly ordered with locally graphitic domains. Physicochemical properties and ultimate utilization of the various coals are discussed with respect to the model structures.     

Response of urinary lipophilic aldehydes and related carbonyl compounds to factors that stimulate lipid peroxidation in vivo

Peroxidation of lipids results in the formation of a number of aldehydic and other carbonyl-containing secondary degradation products. The effect of peroxidative stimuli mediated by vitamin E deficiency, a diet high in polyunsaturated fatty acids (containing cod liver oil), and carbon tetrachloride administration on urinary excretion of a number of lipophilic aldehydes and related carbonyl compounds was examined in rats. These secondary lipid peroxidation products were measured as 2,4-dinitrophenylhydrazine derivatives. All three treatments increased urinary excretion of secondary lipid peroxidation products, although the pattern of excretion of these products varied somewhat among the treatments. Significant increases were found in butanal, hexanal, octanal. butan-2-one, pentan-2-one, hex-2-enal, hepta-2,4-dienal, 4-hydroxyhex-2-enal, 4-hydroxyoct-2-enal, 4-hydroxynon-2-enal, and a number of unidentified carbonyl compounds. These results suggest that urinary excretion of these lipophilic secondary lipid peroxidation products is a useful and noninvasive marker of whole-body lipid peroxidation.     

Modulation of body composition and immune cell functions by conjugated linoleic acid in humans and animal models: Benefits vs. risks

We have reviewed the published literature regarding the effects of CLA on body composition and immune cell functions in humans and in animal models. Results from studies in mice, hamsters, rats, and pigs generally support the notion that CLA reduced depot fat in the normal or lean strains. However, in obese rats, it increased body fat or decreased it less than in the corresponding lean controls. These studies also indicate that t10,c12-CLA was the isomer that reduced adipose fat; however, it also increased the fat content of several other tissues and increased circulating insulin and the saturated FA content of adipose tissue and muscle. Four of the eight published human studies found small but significant reductions in body fat with CLA supplementation; however, the reductions were smaller than the prediction errors for the methods used. The other four human studies found no change in body fat with CLA supplementation. These studies also report that CLA supplementation increased the risk factors for diabetes and cardiovascular disease including increased blood glucose, insulin, insulin resistance, VLDL, C-reactive protein, lipid peroxidation, and decreased HDL. Most studies regarding the effects of CLA on immune cell functions have been conducted with a mixture of isomers, and the results have been variable. One study conducted in mice with the purified c9,t11-CLA and t10,c12-CLA isomers indicated that the two isomers have similar effects on immune cell functions. Some of the reasons for the discrepancies between the effects of CLA in published reports are discussed. Although significant benefit to humans from CLA supplementation is questionable, it may create several health risks in both humans and animals. On the basis of the published data, CLA supplementation of adult human diets to improve body composition or enhance immune functions cannot be recommended at this time.