膳食模式、肠道菌群与结直肠癌

结直肠癌是一种发病率和致死率均极高的肿瘤疾病,其发生和发展由基因、环境、生活方式等多方面因素共同决 定,并往往伴随着肠道微环境的改变。膳食成分是调节肠道微环境的重要因素。现阶段,越来越多的研究关注了饮食模式、膳 食成分和结直肠癌间的关系。本文首先讨论了不同膳食模式对结直肠癌发生风险的影响,证明了西方饮食可能促进结直肠癌 的发生,而地中海饮食、能量限制饮食、素食饮食和生酮饮食对结直肠癌具有一定的预防和干预作用。进一步分析了各类膳食 成分如何通过直接作用或通过调节肠道菌群间接影响了结直肠癌的发生发展。其中,多酚类物质、胡萝卜素、膳食纤维等,可 以维持肠道稳态,改善肠道内炎症及氧化应激等,从而降低结直肠癌的发病风险。而特定膳食成分的缺失或过剩则可以改变 肠道微生物组成,诱导肿瘤相关微生物丰度的升高,造成有毒代谢产物的积累,进而促进肠道炎症和肿瘤的发生。最后,本文 提出了一套针对结直肠癌患者的个性化饮食干预策略思路。利用宏基因组、宏转录组、代谢组等多组学手段,结合人工智能分 析结直肠患者菌群组成及功能上的异常,进一步设计个性化的膳食模式,以实现患者肠道菌群的精准调节,并对结直肠癌患者 进行膳食干预。     

胆汁酸法尼醇X受体在结直肠癌中的研究进展

结直肠癌是人类最常见的恶性肿瘤之一。近年来的研究发现,胆汁酸与结直肠癌的发生和发展息息相关。法尼醇X受体（farnesoid X receptor,FXR）作为主要的胆汁酸受体之一,对于结直肠癌具有抑制和保护性作用。肠道菌群通过代谢胆汁酸参与调控结直肠癌的发生和发展,同时也受到FXR的调控。FXR的激动剂可以作为结直肠癌的潜在治疗药物。     

肠道菌群失衡和结直肠癌关系的研究进展

结直肠癌是最常见的恶性肿瘤之一,发病率逐年上升.研究表明肠道菌群失衡在结直肠癌的发生中可能发挥重要作用,肠道菌群可能通过肠道黏膜屏障受损、慢性炎症反应、细菌酶和毒性代谢产物作用等多种机制促进肿瘤的发生.近年来通过无菌动物实验、基因敲除动物实验以及新一代的高通量测序使人们对肠道菌群和大肠癌间关系的认识不断深化,继而从不同角度提出肠道菌群失衡导致结直肠癌发病的作用模式,本文将结合相关作用模式从肠道菌群先后影响结直肠癌不同发病阶段的角度阐述结直肠癌发生、发展过程中的相关机制,为进一步认识结直肠癌的发病机制和结直肠癌的早期诊疗提供新的思路.     

基于肠道菌群及其代谢物的结直肠癌生物标志物的研究进展

摘 要：肠道菌群是人体内最大和最复杂的微生物群落,与人体健康和疾病密切相关。结直肠癌是一种常见的消化道恶性肿瘤,其发生与进展受到多种因素的影响,其中肠道菌群及其代谢物是重要的调节因素之一。肠道菌群及其代谢物可以通过影响宿主的免疫系统、代谢途径、表观遗传学和信号通路等,促进或抑制结直肠癌的发生及进展。因此,肠道菌群及其代谢物可以作为结直肠癌的生物标志物,用于结直肠癌的筛查、诊断、分期、预后评估和治疗反应监测等。全文对目前已发现的与结直肠癌相关的肠道菌群及其代谢物的检测方法和临床应用的优势、问题以及未来发展方向作一综述,旨在为基于肠道菌群及其代谢物的结直肠癌防治提供参考。     

中药防治肠道菌群相关性结直肠癌的研究进展

结直肠癌发病率和死亡率居我国全部恶性肿瘤的第 3 和第 5 位,严重威胁居民健康。结直肠癌病因复杂,其中 肠道微生态是影响癌变过程的关键环节。肠道菌群是维持人体胃肠道及机体健康的重要因素,肠道微生物病原体在结直肠 癌发病机制包括微生物代谢、宿主免疫和炎症途径的调节、氧化应激与抗氧化防御调节、细菌基因毒素等环节。传统中药 给药方式主要为口服,中药进入胃肠道后不可避免与肠道微生物发生相互作用。中药主要通过调节肠道菌群结构,从而调 节宿主免疫功能,以及氧化应激与抗氧化防御调节等途径实现防治结直肠癌的作用。实验研究证实,中药对肠道微生态系 统的平衡具有很好的保护作用,对菌群失调具有改善作用;中药可以提高宿主抗癌免疫反应以及通过调节肿瘤微环境下的 骨髓来源的细胞功能发挥抗肿瘤疗效;促进有氧培养菌的耐酸能力并抑制了厌氧培养菌的耐酸能力,从而增强了整体肠道 菌群的抗氧化性。另外,中药亦能改善微生物的代谢、减轻代谢性炎症,以及抑制产生大肠杆菌的体外和体内基因毒性, 中草药的药效成分经肠道微生物转化后发挥抗炎、镇痛和抗肿瘤等药理作用。综上,肠道菌群在部分结直肠癌的发生发展 中具有重要作用,调节肠道菌群是中医药防治结直肠癌的重要靶标。     

肠道菌群微生态与结直肠癌的研究进展

近年来中国结直肠癌的发病率逐年升高,已成为最常见的消化道恶性肿瘤之一。随着分子生物学及宏基因组学的深入研究,发现肠道菌群微生态及其代谢模式的改变可通过破坏正常组织细胞DNA、激活致癌信号传导途径,产生促肿瘤代谢物和抑制抗肿瘤免疫反应等多因素来影响结直肠癌的发生和发展。因此,研究者们尝试利用微生态制剂治疗和预防肿瘤。目前,以益生菌和排泄物移植技术为代表的微生态制剂可调节肠道菌群微生态,诱导结直肠癌细胞凋亡和细胞周期阻滞,分泌抗肿瘤细胞因子及调节免疫系统来抗肿瘤。微生态制剂为结直肠癌患者带来了希望,但目前肠道菌群微生态在结直肠癌中的具体作用机制仍不明确,仍需进一步的大样本研究深入探讨。本文就肠道菌群微生态与结直肠癌的研究进展进行综述,以期为结直肠癌的诊治探索新的方法。      

肠道菌群与结直肠癌关系及其研究技术进展

结直肠癌是常见的肿瘤之一,在中国肿瘤发病率中排名第三。肠道菌群对肿瘤增殖、存活、转移与肿瘤发生都产生 重要影响,特别是肿瘤微环境中的代谢物可以刺激炎症细胞诱导慢性炎症反应。肠道菌群会影响机体和调节结直肠甚至整个 消化系统的生理功能,这与结直肠癌有着密切的关系。目前测序技术和细菌‐宿主机制相互作用是研究肠道菌群和结直肠癌 的主要方法,测序技术可以快速大量的对粪便样本进行菌群的种类、基因和功能上的分析,细菌‐宿主相互作用技术可以从实 验角度研究细菌对疾病发生发展的机制,更精准地确定肠道菌群和结直肠癌的关系。但DNA提取差异、引物偏差、测序深度, 以及细菌菌株差异、未知细菌的影响等都制约着研究的进展。随着研究技术的发展,培养组学以及肠道类器官技术为肠道菌 群和结直肠癌关系研究带来了新的技术和方法,一定程度上弥补了测序技术和实验技术的不足。本文就针对肠道菌群和结直 肠癌关系的研究技术展开综述,讨论了其研究进展及发展方向。     

胆结石与结直肠癌关系的临床观察

在西方国家,结直肠癌和胆结石是两种常见病。尸检和临床研究发现这两种病呈正相关。摄入高脂肪和低纤维素与结直肠癌有关。大肠肠腔内容物包括高浓度的胆汁酸是大肠癌肿发生的原因。胆结石的存在和胆囊切除能够引起胆汁和粪便中次级胆汁酸水平的增高。胆汁酸的库存减少和肠肝循环的增多,导致更多的初级胆汁酸在肠道微生物的作用下降解为次级胆汁酸。研究378例结直肠癌病人,男227例,女151例。结肠癌200例,直肠癌162例。14例既有结肠癌又有直肠癌。组织学证实所有病例均     

肠道菌群在肿瘤进程中的作用及其临床研究进展

肠道菌群在调控宿主的生长、发育、营养代谢以及免疫稳态方面具有重要的作用.近年来研究发现,肿瘤患者,特别是结直肠癌患者的肠道菌群多呈现失调的状态,而肠道菌群失调能够通过影响肠道代谢、肠道稳态以及肠道免疫等方面促进或者抑制肿瘤的发生发展.目前,通过干预肠道菌群来进行肿瘤治疗的临床实践已经显示出了良好的疗效和巨大的潜能.本文主要论述肠道菌群在肿瘤发生发展进程中的作用及其机制,以及目前利用肠道菌群治疗肿瘤的相关临床研究进展.     

肠道菌群与结直肠癌关系研究进展*

人体肠道菌群代谢成分通过与受体结合、刺激炎症因子分泌,与其他变化一起,引起炎症反应,最终导致结直肠癌（colorectal cancer ,CRC ）的发生。而肠道内的益生菌则通过屏障作用、抑制DNA 损伤等机制保护肠道黏膜,抵御CRC 的发生,并可被用于预防及辅助治疗CRC 。胃肠道手术可以影响肠道菌群的代谢,影响微生态平衡。本文将针对肠道菌群与结直肠癌关系的最近进展进行综述。     

Etoposide, dexamethasone, cytarabine, and cisplatin in vincristine, doxorubicin, and dexamethasone-refractory myeloma

Based on remarkable activity in refractory lymphomas, a combination of etoposide, cisplatin (both administered by 4-day continuous infusions), cytarabine (Ara-C), and dexamethasone (EDAP) was evaluated in 20 patients with advanced myeloma refractory to standard melphalan and prednisone (MP) and/or vincristine, Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), and dexamethasone (VAD) and even to high doses of melphalan (HDM) (seven patients). Forty percent of patients responded regardless of previously recognized risk factors (eg, duration of drug resistance, tumor mass, and serum lactic dehydrogenase [LDH] level). While the median survival was only 4.5 months, patients with good performance (Zubrod less than 2) and low or intermediate tumor stage survived more than 14 months compared with only 2 months for the remaining group. EDAP could be readily administered in the outpatient clinic, but neutropenic fever prompted hospital admission in 80% of patients, half of whom developed penumonia and sepsis, a fatal outcome in four patients. Severe myelosuppression was of short duration, so that subsequent cycles could be administered every 3 to 4 weeks. No serious extramedullary toxicity, including renal toxicity, was encountered. Marrow toxicity and hence infectious complications may be reduced by elimination of Ara-C without compromising treatment efficacy. We conclude that the lack of cross-resistance with VAD and even HDM makes EDAP or a similar combination an attractive regiment to be formally explored in an alternating sequence with VAD in high-risk myeloma.     

Stress,coping, and hope

Hope is discussed in many literatures and from many perspectives. In this essay hope is discussed from the vantage of psychology and stress and coping theory. Hope and psychological stress share a number of formal properties: both are contextual, meaning‐based, and dynamic, and both affect well‐being in difficult circumstances. Two assumptions underlie this essay: (1) hope is essential for people who are coping with serious and prolonged psychological stress; and (2) hope is not a perpetually self‐renewing resource; it has peaks and valleys and is at times absent altogether. The relationship between hope and coping is dynamic and reciprocal; each in turn supports and is supported by the other. This relationship is illustrated with two adaptive tasks common across situations that threaten physical or psychological well‐being—managing uncertainty and coping with a changing reality. The essay describes ways in which coping fosters hope when it is at low ebb as well as ways in which hope fosters and sustains coping over the long term. Copyright © 2010 John Wiley & Sons, Ltd.     

Myelodysplastic syndromes, aging, and age: correlations, common mechanisms, and clinical implications

Myelodysplastic syndromes (MDS) are a heterogenous group of myeloid neoplasms that develop primarily in elderly patients. Although a specific molecular basis for the predominant incidence of MDS in higher age groups remains unknown, several lines of evidence suggest that the biology of aging and the pathogenesis of MDS share several genetic, epigenetic, and molecular features. The current review attempts to delineate these common aspects as well as additional discriminative features that are specific for MDS and thus help explaining disease-evolution and progression. In addition, the present review discusses age as an important prognostic factor and co-variable to be considered in treatment algorithms in MDS.     

Appendectomy,tonsillectomy, and neoplasia

Reports in the literature that study the frequency of cancer in individuals who have had their tonsils or appendix or both removed are reviewed. Some investigators found a high incidence of solid cancers—in particular, breast and colon neoplasms—in female patients who have had appendectomy, but others disagreed. The association of tonsillectomy and/or appendectomy with the later development of malignant lymphomas is not proven.     

Premenopausal intakes of vitamins A, C, and E, folate, and carotenoids, and risk of breast cancer.

Intakes of vitamins A, C, and E, folate, and carotenoids have been hypothesized to reduce the risk of breast cancer. However, previous epidemiological studies on these nutrients and breast cancer risk have been inconclusive, and have included primarily postmenopausal women. We examined the intake of these nutrients in relation to breast cancer risk among 90,655 premenopausal women ages 26-46 years in 1991 in the Nurses' Health Study II. Nutrient intake was assessed with a validated food-frequency questionnaire at baseline in 1991 and in 1995. During 8 years of follow-up from 1991 to 1999, we documented 714 incident cases of invasive breast cancer. Overall, none of the vitamins and carotenoids was strongly related to a reduced risk of breast cancer. However, intake of vitamin A, including preformed vitamin A and carotenoids, was associated with a reduced risk of breast cancer among smokers; participants in the highest quintile of total vitamin A intake had a multivariate relative risk of 0.28 (95% confidence interval 0.12-0.62; P, test for trend <0.001; P, test for interaction <0.001) compared with those in the lowest quintile of intake. We found no evidence that higher intakes of vitamins C and E, and folate in early adult life reduce risk of breast cancer. However, intake of vitamin A may be related to a reduced risk of breast cancer among smokers.