肿瘤流行病学和病因学研究对转化医学的重要贡献

进入21世纪以来,世界大多数国家肿瘤研究策略发生了重大调整,实行了战略性转移,更加强调将基础研究成果尽快转化为临床应用,即转化医学.例如,美国国立卫生研究院(NIH)成立了转化医学研究中心,强调从分子影像诊断技术到血清标志物的临床应用,从基因组学研究到寻找肿瘤化学治疗、放射治疗的分子靶点,取得了可喜成效.注重转化医学,加强基础应用性研究,从卫生经济学角度出发,可以将有限的资源最大限度地投入到解决实际问题中.     

卵巢癌的病因流行病学研究进展

卵巢癌因发病隐匿,就诊时多已届晚期,治疗效果及预后很差,积极开展病因学研究及早期阻断卵巢癌的诱因很有必要。该文复习了近几年有关卵巢癌的病因流行病学文献,从环境、生殖、行为和遗传因素4个方面进行综述,发现卵巢癌的发生与以上诸多因素有关,早期预防甚为重要。     

The hygienic hypothesis and transformations in etiological knowledge: from causal ontology to ontogenesis of the body

The objective of this article is to systematize the principal recent research results pertaining to the so-called hygienic hypothesis, which establishes an etiological link between the increasing incidence of allergic diseases and the decreasing incidence of infectious diseases in the industrialized countries of the Western world. The author contends that the current debate on the hygienic hypothesis indicates significant transformations in the understanding of disease etiology, perhaps even as important as the transformations in the 19th century during the process leading to the constitution of modern medicine and the identification of infectious disease causal agents.     

生物学标志物在大肠癌化学预防中的应用研究

建立大鼠大肠癌动物模型,选用一系列生物学标志物,观察茶对大肠癌的化学预防效果。结果 表明,与阳性对照组相比,在１６和３２周,绿茶组和茶色素组动物大肠细胞增殖细胞核抗原（ＰＣＮＡ）标记指数和核仁组成区嗜银蛋白（ＡｇＮＯＲｓ）颗粒数目显著减少,ｒａｓ－ｐ２１蛋白表达也降低;而且,绿茶和茶色素还抑制了Ｂｃｌ－２蛋白的表达,诱导了Ｂａｘ蛋白的表达。     

Unbiased vs. Conservative estimators of etiological fractions: Examples of misclassification from studies of occupational lung cancer

Theoretical studies emphasize the importance of making unbiased etiological fraction estimates. In empirical works, however, the published estimates are usually conservative. The purpose of the present report is to study, empirically, the numerical magnitude of such conservative biases. Examples from the literature on occupational exposure and lung cancer are reported. It is demonstrated that conservative bias may decrease a numerical estimate by more than a factor 10 and that decreases by a factor 2 or 3 are not unusual. It is concluded that it is important, in future review studies, to pay attention to the magnitude of the conservative biases in the published empirical estimates and to put most emphasis on the least biased estimates in the review process.     

脑卒中病因流行病学的家系研究

脑卒中是一种由多个遗传和环境因素影响的病因异质性疾病[1],大量研究表明遗传因素在脑卒中的发生、发展、结局和预后等方面发挥着不容忽视的作用.家系研究通过发现与共享基因和(或)共享环境有关的危险因素来揭示脑卒中等复杂性疾病的潜在病因,是探索遗传和环境相对作用、确定疾病易感基因的最佳策略.近10余年来,不断涌现的各种组学技术、现代分子生物学检测、计算机信息化技术以及高效能统计分析方法为家系资料在遗传流行病学研究中的应用提供了可行性.本文对脑卒中尤其是缺血性脑卒中遗传易感性的家系研究进行综述.     

Providers' knowledge,attitudes, and practices related to colorectal cancer control in Brazil

In Brazil, colorectal cancer (CRC) is the fourth most common cause of cancer-related death among men, and the third most common among women. We aimed to examine CRC screening-related knowledge, attitudes, and practices among physicians and nurses working in Brazil's network of health units, and to describe the capacity of these units for CRC screening. In 2011, 1600 health units were randomly selected from all 26 states and the Federal District. One coordinator and one health care provider were selected for the interview. Response rates were 78% for coordinators, 34% for physicians, and 65% for nurses. The Brazilian National Cancer Institute (INCA) recommendations for CRC screening were not often used in the health units, but screening outreach and use of CRC exams were more common in units that were using them. Physicians and nurses differed in most characteristics, and in their knowledge, attitudes, and practices of CRC screening. Forty-seven percent of physicians reported not conducting CRC screening compared to 65% of nurses. Fecal occult blood test was most often used by physicians and nurses, but fewer physicians than nurses perceived this exam as very effective in reducing CRC mortality. Physicians' gender, years since graduation, and geographical region of practice in Brazil were associated to CRC screening practice. The findings may reflect the low influence of INCA CRC screening recommendations, physicians receiving their medical education when CRC burden in Brazil was of low concern, and the lack of CRC screening capacity in some regions of Brazil.     

A blended knowledge translation initiative to improve colorectal cancer staging [ISRCTN56824239]

Background  

A significant gap has been documented between best practice and the actual practice of surgery. Our group identified that colorectal cancer staging in Ontario was suboptimal and subsequently developed a knowledge translation strategy using the principles of social marketing and the influence of expert and local opinion leaders for colorectal cancer.     

Iron and colorectal cancer risk: human studies

Some reports have associated iron with cancer risk, particularly of the colorectum. This review will focus on the human studies that have investigated this association. Comparative studies were sought in which people with and without colorectal neoplastic lesions, either cancers or adenomatous polyps, were assessed for iron exposure. Iron exposure variables included dietary iron intake, iron vitamin supplementation, body iron stores as measured by ferritin or transferrin saturation, and gene status for hereditary hemochromatosis. Medline was searched for published reports using the key words iron, cancer, colon, rectum, ferritin, transferrin, and hemochromatosis. In addition, the Cochrane Library was searched for relevant studies and several authors were contacted to investigate their awareness of unpublished studies. Studies were categorized by study design and ranked for quality of innovation in design, sample size, and thoroughness of iron status ascertainment. Thirty-three studies were reviewed in 26 publications. Of the larger studies, approximately three-quarters supported the association of iron, in all three strata of exposure, with colorectal neoplasia risk. Because iron is broadly supplemented in the American diet, the benefits of iron supplementation need to be measured against the long-term risks of increased iron exposure, one of which may be increased risk of colorectal cancer.     

Contribution of phenomenological studies to nursing care

This essay reflects the contributions of phenomenological studies to nursing care, as exemplified in the knowledge concerning the adhesion of persons suffering from coronary diseases to daily idle talk. It considers that the understanding of human manifestations allows one to interpret attitudes and behaviors and that the contributions of phenomenological studies can facilitate the reach of excellence in nursing care.     

A critical review of studies on vitamin D in relation to colorectal cancer

Vitamin D intake has been hypothesized to reduce the risk of several types of cancer. Vitamin D and its analogues have demonstrated anticancer activity in vitro and in animal models. However, the risk of colorectal cancer in relation to dietary vitamin D remains controversial. A literature search was performed for articles on epidemiologic studies of vitamin D and colorectal cancer and the mechanisms involved. Studies that combine multiple sources of vitamin D or examine serum 25(OH)D3 usually find that above-average vitamin D intake and serum metabolite concentrations are associated with significantly reduced incidence of colorectal cancer. A number of mechanisms have been identified through which vitamin D may reduce the risk of colorectal and several other types of cancer. Although studies that include vitamin D from all sources or serum 25(OH)D3 usually show significantly reduced incidence of colorectal cancer in association with vitamin D, analyses limited to dietary vitamin D tend to have mixed results. The likely reason that dietary vitamin D is not a significant risk reduction factor for colorectal cancer in many studies is that dietary sources provide only a portion of total vitamin D, with supplements and synthesis of vitamin D in the skin in association with solar UV-B radiation providing the balance. There is strong evidence from several different lines of investigation supporting the hypothesis that vitamin D may reduce the risk of colorectal cancer. Further study is required to elucidate the mechanisms and develop guidelines for optimal vitamin D sources and serum levels of vitamin D metabolites.     

Alcohol, one-carbon metabolism, and colorectal cancer: recent insights from molecular studies

A growing body of evidence implicates alcohol intake as a risk factor for colorectal cancer. Until recently, most of the data were based on epidemiologic data that examined alcohol intake in relation to risk of colorectal neoplasia, but the evidence has now been broadened by recent molecular studies on mechanisms. In particular, a number of observations strongly support a role for alcohol acting through disruptions in one-carbon metabolism. Excessive alcohol intake is a fairly consistent risk factor for colorectal neoplasia in most studies, and studies show much higher risks of colorectal neoplasia in those with high alcohol and low folate than with high alcohol or low folate individually. Interactions between high alcohol-low folate and the MTHFR677TT genotype with risk of colorectal neoplasia suggest that alcohol is acting through its effects on one-carbon metabolism because the combination of high alcohol-low folate and the MTHFR677TT genotype are related to markedly elevated serum levels of homocysteine and to DNA hypomethylation. In addition, in Japanese studies, consumers of alcohol possessing the ALDH2*2 allele, who have very elevated levels of acetaldehyde, are at high risk for colorectal cancer. The relatively high prevalence of the ALDH2*2 allele may thus account for the stronger association between alcohol and colorectal neoplasia that is frequently observed in studies in Japanese populations. Further research integrating studies with more detailed data on alcohol intake levels and patterns, folate and other related nutrient status, and relevant genotypes may help clarify unresolved questions regarding the health consequences of moderate to high alcohol drinking.