散发性大肠腺瘤性息肉患者粪便中APC基因突变的意义及与中医体质的关系

[目的]观察粪便中散发性大肠腺瘤性息肉APC基因突变的意义,探讨易出现APC基因突变的中医体质类型。[方法]采用QIAamp DNA Stool Mini Kit 51504提取42例大肠腺瘤性息肉、8例非腺瘤性息肉、12例大肠癌患者及23例正常人群粪便的DNA,运用聚合酶链反应—单链构象多态分析法(PCR-SSCP)检测APC基因的突变情况;通过问卷形式调查散发性大肠息肉患者的中医体质类型。[结果]42例大肠腺瘤性息肉患者的粪便APC基因的突变率为21.43%(9/42);8例非腺瘤性息肉及23例正常组APC基因的突变率均为0;12例大肠癌患者粪便中APC基因突变率为33.33%(4/12);总突变率为15.30%。腺瘤性息肉组与正常组比较差异有统计学意义(P0.05);腺瘤性息肉与大肠癌组比较差异无统计学意义(P0.05)。粪便APC基因突变与中医体质无关(P0.05)。[结论]检测粪便中APC基因的突变率有助于大肠腺瘤性息肉筛查,大肠腺瘤性息肉粪便中APC基因的突变与中医体质无明显关系。     

粪便中p53与APC突变检测在大肠癌诊断中的意义

目的探讨在大肠癌患者粪便中检测p53、APC基因突变的可行性及其应用前景和意义。方法从36例大肠癌患者、10例大肠腺瘤患者以及30例正常对照者的粪便中分别提取DNA,应用PCR-SSCP法检测粪便中p53、APC基因突变情况。结果36例大肠癌患者粪便中p53及/或APC基因突变检出率为77.78%(19/36),二者突变率分别为52.78%(19/36)和36.11%(13/36);10例大肠腺瘤中p53基因突变检出率为0%,APC为20%;30例正常对照粪便中p53、APC基因突变检出率均为0%。p53的突变随大肠癌分化程度的降低而增高(P<0.05);APC基因突变与大肠癌组织学类型无关(P>0.05)。结论联合检测粪便中p53与APC突变在大肠癌诊断和筛查中有潜在的应用价值。     

几种粪便脱落细胞检查方法的大肠癌筛检效率比较

目的 评价不同粪便脱落细胞检查方法的大肠癌筛检效率.方法 对814例结肠镜检查者分别经清肠液法、二次自然粪便法、磁选法、自然排便联合清肠液液基法提取粪便脱落细胞,进行细胞学诊断.部分经清肠液法受检者提取细胞后行DNA核定量分析(清肠液+DNA核定量分析法).部分二次自然粪便法提取的粪便行基因检测.二次自然粪便法和自然排便联合清肠液液基法提取的粪便同时进行粪隐血检测.结果 粪便脱落细胞检出大肠癌的敏感性为66.27%(112/169),特异性为99.56%(225/226).大肠癌患者粪便中提取异犁细胞的阳件率与大肠癌分化程度和Duke分期无关(P＞0.05).二次自然排便法、自然排便联合清肠液液基法、清肠液+DNA核定量分析法筛检大肠癌的敏感性(分别为76.09%、68.29%、76.92%)优于单纯清肠液法和磁选法(分别为26.31%、43.24%).粪便脱落细胞p53、K-ras、腺瘤性息肉病(APC)基因检测阳性率与癌组织相应基因检测的一致率为83.33%(25/30)、9/10、9/10.基因检测的阳性率低于粪便脱落细胞学检测.联合进行粪隐血和粪脱落细胞学检测检出大肠癌的敏感性(93.10%)高于单独进行粪隐血试验(80.46%)和粪便脱落细胞学检测(73.56%).结论 粪便脱落细胞学检查是大肠癌筛检的有效手段.利用液基薄层技术对患者自然排便或清肠液进行两次筛查并联合粪隐血检测是最佳筛检方案.     

人粪便SFRP2基因甲基化分析对结直肠癌的诊断价值

目的探讨人粪便中分泌型卷曲相关蛋白2(SFRP2)基因甲基化分析用于结直肠癌(CRC)早期诊断的可行性。方法从87例结直肠癌或良性病变的患者及24例正常对照者的粪便中分别提取DNA,采用甲基化特异性PCR(MSP)技术分析其SFRP2基因甲基化状态。结果CRC、腺瘤、增生性息肉和溃疡性结肠炎患者的SFRP2基因甲基化阳性率分别为94.2%(49/52)、52.4%(11/21)、37.5%(3/8)和16.7%(1/6)。1例正常对照SFRP2基因甲基化检测阳性。检测SFRP2基因甲基化诊断CRC及癌前病变的敏感性和特异性分别为90.5%和85.4%。结论SFRP2基因甲基化是CRC进展过程中的早期事件。粪便SFRP2基因甲基化分析可望成为CRC早期无创诊断或CRC高风险人群筛查的新途径。     

粪便DNA中MGMT、XAF1基因启动子甲基化联合检测在结直肠癌筛查中的应用研究

目的使用甲基化特异性PCR(MSP)方法检测粪便DNA中O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)、X染色体连锁凋亡抑制蛋白相关因子1(XAF1)基因启动子甲基化情况,并探讨其在结直肠肿瘤诊断中的意义。方法收集40例结直肠腺癌、40例腺瘤性息肉、52例正常对照住院患者粪便标本,使用试剂盒提取其粪便中肠道脱离细胞DNA,通过MSP方法检测其MGMT、XAF1基因启动子甲基化情况。结果 MGMT、XAF1基因启动子甲基化在结直肠腺癌中的阳性率分别为50.0%、55.9%;在腺瘤性息肉中的阳性率分别为42.1%、52.6%;二者联合检测在结直肠腺癌及腺瘤性息肉中的阳性率分别为73.5%、68.4%;特异性为52.0%。结直肠腺癌患者粪便中粪便潜血阳性率为35.3%,CEA阳性率为35.3%。结论通过试剂盒提取粪便DNA具有较高成功率;粪便DNA中MGMT、XAF1基因启动子甲基化状态用于检测结直肠腺癌及腺瘤性息肉具有较高的敏感性。检测粪便基因甲基化有望成为CRC高风险人群筛查的一个重要途径。     

大肠癌的相关基因表达和早期诊断意义

目的探讨大肠癌及癌前病变多个相关基因表达水平和诊断意义方法用RT-PCR及PCR-SSCP方法分别检测大肠癌、大肠腺瘤、溃疡性结肠炎及正常组织中p53,p73,DCC,APC,C-myc,K-ras基因mRNA表达及DNA突变,相比较各组间进行x2检验结果在结肠癌、结肠腺性息肉、溃疡性结肠炎、正常组织中的高表达率分别为55%,57%,50%,0%.突变率分别为37.5%,14.3%,8.3%,0%,有显著差异(P<0.05).p73基因高表达率分别为82.5%,81.6%,41.7%,15.4%,也有显著差异(P<0.05),仅大肠癌组检出7例p73基因缺失.DCC基因的高表达率、突变率、缺失率在大肠癌分别为5%,47.5%,40%,结肠腺瘤分别为4.1%,14.3%、18.4%,溃疡性结肠炎分别为16.7%,25%,0%,正常组仅1例高表达.APC基因在大肠癌的高表达率、突变率、缺失率分别为57.5%,30%,5%,大肠腺瘤的高表达率、突变缺失率分别为44.9%,34.7%,2.0%Cmyc基因在大肠癌、大肠腺瘤、溃疡性结肠炎、正常对照组织高表达率分别为95%,63.3%,66.7%,0%.K-ras基因大肠癌、大肠腺瘤、溃疡性结肠炎中高表达率分别为60%,57.1%,58.3%.突变率分别为40%,24.5%,16.7%,正常组织无高表达及突变.结论本研究提示p53基因高表达在大肠癌前病变即已发生,与大肠癌的发展阶段有关.p53基因突变可能与腺瘤的癌变有关.p73高表达在大肠腺瘤即已发生,且p73基因缺失可能与大肠腺瘤的癌变有关.p73在同位癌及癌组织中表达有显著差异,可能为新发现的癌基因.DCC基因以突变和缺失方式参与大肠癌的发生,但出现较晚,对大肠癌的基因诊断有重要意义.APC基因在大肠腺瘤阶段即已发生较高的异常表达.p53,p73,APC基因改变为大肠癌发生的早期事件,对大肠癌早期诊断有重要意义.C-myc,K-ras基因的高表达与大肠肿瘤的进展过程有关,可作为大肠癌的早期基因诊断的重要标志物.在大肠腺瘤和溃疡性结肠炎已发生大肠肿瘤的基因表达水平改变,可被认定为大肠肿瘤癌前病变.     

内蒙古包头地区大肠癌患者K-ras和B-raf基因突变

目的了解内蒙古包头地区大肠癌(CRC)患者肿瘤组织中K-ras和B-raf基因突变的情况。方法应用ARMS-PCR荧光探针法分别检测当地632例CRC患者肿瘤组织中K-ras和B-raf基因的突变情况,分析突变与患者临床相关参数的关系。结果研究人群中K-ras基因常见7种突变形式均有检出,K-ras基因总体突变率为37.50%(237/632),突变发生以单一位点为主,在总体突变中占比95.78%(227/237),突变率最高的三个位点为:Gly12Asp、Gly13Asp和Gly12Val,分别占总体突变的40.93%(97/237)、21.94%(52/237)和17.72%(42/237);发现两位点同时发生占总体突变的3.80%(9/237),多位点同时发生突变者占总体突变的0.42%(1/237);女性患者的突变率明显高于男性(χ~2=6.769,P=0.009);≥60岁老年患者的突变率明显高于60岁(χ~2=11.510,P=0.001);B-raf基因V600E突变发生21例(3.32%),其中18例为K-ras基因野生型,3例为K-ras基因突变型;B-raf基因V600E突变与患者性别、年龄和肿瘤部位无相关性。结论包头地区CRC患者中K-ras基因发生突变的概率较大,突变以单一位点为主,且存在两个或多位点同时突变的个体,突变以女性和60岁及以上老年患者多见;B-raf基因突变率较低,且可与K-ras基因突变共存。     

联合检测粪便APC、K-ras基因突变及BAT-26位点不稳定在结直肠癌早期诊断中的应用

目的探讨联合检测粪便APC、K-ras基因突变及BAT-26微卫星位点在结直肠癌早期诊断中的价值。方法以52例结直肠癌患者、35例大肠良性病变患者和24例健康对照者为研究对象,以其粪便为材料,应用聚合酶链反应单链构象多态性分析（PCR-SSCP）技术,检测BAT-26位点微卫星不稳定性、K-ras第一外显子和APC第15外显子突变密集区的变异。结果52例结直肠癌患者,其粪便APC、K-ras基因突变及BAT-26微卫星位点检出率分别为48.1%（25/52）、42.3%（22/52）和17.3%（9/52）;联合检测这三个靶点对结直肠癌和腺瘤的检出率为分别为76.9%、28.6%。结论联合检测粪便APC、K-ras基因突变及BAT-26微卫星位点是一种敏感性较高的结直肠癌早期诊断方法。     

粪便标本中 SFRP1和 WIF-1基因启动子甲基化在大肠癌早期筛查中的意义

目的：探讨联合检测粪便中分泌型卷曲蛋白1（SFRP1）和Wnt途径抑制因子-1（WIF-1）基因启动子甲基化作为大肠癌（ CRC）早期筛查指标的可行性。方法收集48例CRC患者、35例大肠腺瘤患者、32例大肠增生性息肉患者及30例健康人的粪便样本,采用甲基化特异性PCR技术分析样本中SFRP1和WIF-1基因启动子甲基化状态。结果 CRC患者粪便中SFRP1和WIF-1基因启动子甲基化率分别为68．8％和60．4％,腺瘤患者分别为57．1％和42．9％,增生性息肉患者分别为21．9％和18．8％;两者联合检测CRC和大肠腺瘤的敏感度分别为77．1％和65．7％,特异度为93．3％。2个基因甲基化水平在CRC和腺瘤患者的粪便样本中均显著高于增生性息肉和健康人群（P均＜0．05）。此外,SFRP1和WIF-1基因甲基化与临床病理特征无明显相关性。结论检测粪便中SFRP1和WIF-1基因启动子甲基化有望成为CRC早期筛查的一种非侵入性检测方法,在早期筛查和诊断中具有潜在的应用价值。     

粪便脱落细胞多基因变异与大肠癌早期诊断的关系

采用PCR－SSCP分析技术,检测40例大肠癌癌组织中抑癌基因APC第11外显子、MCC等10外显子和癌基因K－ras第1显子的变异情况,并在20例大肠癌患者粪便中进行三种基因的检测。结果：APC第11外显子和MCC第10外显子在A／B期变异率明显高于C／D期,K－ras第1外显子突变率在粘液癌中明显高于腺癌,且随分化程度降低有降低的趋势;在粪便中均检测到与肿瘤组织中三种基因相应的变异。认为检测烘便脱落细胞基因变异可用于大肠癌早期诊断,APC/MC和K-ras可用于估计大肠癌预后。     

New method for the determination of fecal consistency and its optimal value in the general population

BACKGROUND: Although fecal consistency is an important factor, there has been only one study measuring this parameter. We developed a new method to measure fecal consistency and studied the relationship between fecal consistency and other fecal factors, including water content and weight. METHODS: The new method is a modification of the method of Exton-Smith and used an even balance. Subjects in the initial trial were 26 healthy women. Subsequently, fecal consistency was measured in a representative sample of the general Japanese population, in order to evaluate the optimal value to maintain large bowel function. RESULTS: Correlations between fecal consistency and fecal water content and weight were statistically consistent, although not highly correlated with each other. The optimal mean value was around 300 cm2: 'normal' in 'subjective defecatory state', 295.5 cm2 and 305.2 cm2; 'once/day' in 'defecation frequency', 296.1 cm2 and 310.2 cm2; 'soft and plump' in 'fecal characteristics', 293.6 cm2 and 298.3 cm2, in males and females, respectively. The coefficient of variation of this method ranged from 5.2% to 6.3%. CONCLUSIONS: This method is thought to be applicable to large-scale epidemiological surveys. The optimal value of fecal consistency in the general population was evaluated at approximately 300 g/cm2.     

Effect of calcium carbonate and aluminum hydroxide on human intestinal function

The effect of calcium carbonate (6 g daily) and of aluminum hydroxide (Amphojel, 7.2 g daily) on human gastrointestinal function was examined because these popular antacids have a documented effect on fecal fat, an undocumented association with constipation, and a putative ability to ameliorate cocarcinogenic effects of bile acids and fatty acids on colonic mucosa. Intake-output studies were conducted over periods of three weeks during which time dietary intake was controlled (20 g fiber daily), and the order of treatment (control, calcium carbonate, aluminum hydroxide) was randomized. Neither calcium carbonate nor aluminum hydroxide altered the mean intestinal transit time of eight subjects. Calcium carbonate increased daily output of feces from 106±30 (SD) to 131 ±41 g, of fecal fatty acids from 7.9±1.4 to 16.8±15.4 mmol, and of fecal 3-hydroxy-bile acids from 411±223 to 769±505 mol. Aluminum hydroxide increased daily output of feces to 143±43 g, of fecal fatty acids to 12.4 ±5 mmol, and of fecal bile acids to 735 ±592 mol. Both Ca²⁺ and Al³ precipitated deoxycholate when these ions were incubated in vitro. These observations help to explain how these two antacids may lower blood lipids and ameliorate the effects of fecal bile acids and fatty acids on colonic mucosa.     

Fecal microbiota transplantation for fulminant Clostridium difficile infection in an allogeneic stem cell transplant patient

We present a case of severe Clostridium difficile infection (CDI) in a non‐neutropenic allogeneic hematopoietic stem cell transplant recipient who was treated successfully with fecal microbiota therapy after standard pharmacologic therapy had failed. Following naso‐jejunal instillation of donor stool, the patient's symptoms resolved within 48 h. Bowel resection was averted. This is the first case in the literature, to our knowledge, to describe fecal microbiota therapy in a profoundly immunocompromised host with severe CDI. We propose that fecal microbiota therapy be considered as a therapeutic option in immunosuppressed patients with refractory severe CDI.     

Fecal transplant against relapsing Clostridium difficile-associated diarrhea in 32 patients

Abstract

Clostridium difficile-associated disease (CDAD) with frequent watery stools, sometimes with painful bowel movements, fever and sickness, is probably the major known cause of antibiotic-associated diarrhea and colitis, most probably depending on a disruption of the normal intestinal balance in the microbiome. In this study, we have inoculated a mixture of fecal microbes – as an enema – originating from a healthy Scandinavian middle-aged donor, regularly re-cultivated under strict anaerobic conditions for more than 10 years, to 32 patients. Twenty-two patients (69%) were durably cured. In those patients receiving the transplant by colonoscopy, four out of five were cured. To the best of our knowledge, this is the first time a fecal culture of microbes has retained the possibility for years to cure a substantial number of patients with CDAD.     

Fecal microbiota transplantation in treating Clostridium difficile infection

Clostridium difficile infection (CDI) is an increasingly common and severe international health problem. Customary treatment of this infection, usually with antibiotics, is often ineffective and its recurrence is common. In recent years the treatment of recurrent or refractory CDI by the transfer of stool from an uninfected person, so called fecal “microbiota transplantation” has become recognized as effective and generally safe. The effectiveness of this novel treatment is incompletely defined but is likely to be due to its correction of the intestinal dysbiosis that characterizes the disease. Practical methods for the administration of the transplantation have been described. This review summarizes the current reported experiences with fecal microbiota transplantation in the treatment for CDI.     

Bacterial enzymes used for colon-specific drug delivery are decreased in active Crohn's disease

Enzymes produced by colonic microflora have been proposed for triggering local delivery of antiinflammatory azo-bond drugs and prodrugs to the colon. This approach could be advantageous in steroid treatment of inflammatory bowel diseases, thus sparing steroids' side effects. We recently demonstrated that the metabolic activity of digestive flora, assessed on the activity of fecal glycosidases, was decreased in patients with active Crohn's disease. In the present study, the azoreductase activity in feces of 14 patients with active Crohn's disease was decreased (11.39±7.93 mU/g F) as compared with 12 healthy subjects (51.13±21.39 mU/g F). -d-Glucosidase and -d-glucuronidase activities in fecal homogenates incubated under anaerobic conditions were also decreased in patients. These data bring into question the therapeutic usefulness for those patients of azo-bond drugs and glycoside prodrugs. They could explain the therapeutic failure of some of those drugs in active ileocolic and colic Crohn's disease.     

Normal pancreatic secretion in children with progressive familial intrahepatic cholestasis type 1

Objective. Progressive familial intrahepatic cholestasis type 1 (PFIC1) is a rare, autosomal, recessive, inherited disease resulting from mutations in the ATP8B1 gene which is expressed at high levels in the small intestine and pancreas and at lower levels in the liver. Given this expression pattern, patients might be expected to have a pancreatic phenotype. Although pancreatitis and steatorrhea have been reported in patients with PFIC1, the available data on pancreatic function are not fully convincing. Therefore, the objective of this study was to assess exocrine pancreatic function in patients with PFIC1. Material and methods. Three subjects with a diagnosis of PFIC1 were included in the study. The diagnosis was confirmed by molecular analysis of ATP8B1. Prior to surgical treatment (biliary diversion), two patients had steatorrhea and in the third patient, a borderline value for fecal fat excretion was documented. In one patient, liver transplantation also was subsequently performed. Exocrine pancreatic secretion was assessed by the use of fecal elastase-1 and chymotrypsin tests. Fecal lipase concentrations were determined in order to exclude isolated lipase deficiency. Other typical diagnostic procedures were performed annually. Results. The results of the fecal tests were within the normal range. None of the three patients experienced any episodes that could be related to acute or chronic pancreatitis. Laboratory tests including serum amylase and lipase tests were always normal. Abdominal ultrasonography findings did not show any pancreatic pathology. Conclusions. Pancreatic secretion in the study patients with progressive familial intrahepatic cholestasis type 1 was normal. The observed steatorrhea was not related to pancreatic insufficiency.     

Bacteriophages as Fecal Pollution Indicators

Bacteriophages are promising tools for the detection of fecal pollution in different environments, and particularly for viral pathogen risk assessment. Having similar morphological and biological characteristics, bacteriophages mimic the fate and transport of enteric viruses. Enteric bacteriophages, especially phages infecting Escherichia coli (coliphages), have been proposed as alternatives or complements to fecal indicator bacteria. Here, we provide a general overview of the potential use of enteric bacteriophages as fecal and viral indicators in different environments, as well as the available methods for their detection and enumeration, and the regulations for their application.