Abnormally methylated genes are increasingly being used as cancer biomarkers 1, 2 . For clinical applications, it is important to precisely determine the number of methylated molecules in the analyzed sample. We here describe a digital approach that can enumerate one methylated molecule out of ~5000 unmethylated molecules. Individual DNA fragments can be amplified and analyzed either by flow cytometry or next generation sequencing instruments. Using methylated vimentin as a biomarker, we tested 191 plasma samples and detected cancer cases with 59% sensitivity (95% CI, 48%-70%) and 93% specificity (95% CI, 86%-97%). Using the same assay, we analyzed 80 stool samples and demonstrated 45% sensitivity for detecting colorectal adenomas (23%-68%), 41% COMPETING INTERESTS STATEMENTThe authors declare competing financial interests: details accompany the full-text HTML version of the paper at http://www.nature.com/naturebiotechnology/. NIH Public Access Author ManuscriptNat Biotechnol. Author manuscript; available in PMC 2010 March 30. Published in final edited form as:Nat Biotechnol. 2009 September ; 27(9): 858-863. doi:10.1038/nbt.1559. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript sensitivity for detecting cancer (21%-64%), and 95% specificity (82%-99%). This digital quantification of rare methylation events should be applicable to diagnostic evaluations of clinical samples, to preclinical assessments of new epigenetic biomarkers, and to quantitative analyses of epigenetic biology.In humans, DNA methylation is largely restricted to cytosines within 5′-CpG dinucleotides. This covalent modification of DNA functions as an important mediator of gene regulation and, together with covalent modifications of histone proteins, forms the cornerstone for the burgeoning field of epigenetics. Though cancers are globally hypomethylated 3 , specific regions of genes have been shown to be hypermethylated in association with transcription silencing 4 . In addition to its implications for gene regulation, DNA methylation is providing a new generation of cancer biomarkers 5 . Though mutant sequences provide exquisitely specific biomarkers of this class 6, 7 , their utility is compromised by their heterogeneity: the same gene can be mutationally inactivated through many different mechanisms or mutated at many different positions. In contrast, DNA hypermethylation in cancers often affects identical residues in the regulatory regions of particular genes, providing major advantages in biomarker test design. Accordingly, many studies have employed DNA methylation of specific genes for diagnostics development 2,4,5,8 . Such diagnostic tests can in principle be used for early detection of cancers, for assessing prognosis, and for determining the effects of therapy or detecting residual disease.The majority of diagnostic tests based on DNA methylation have employed bisulfite to convert cytosine residues to uracils. This conversion alters the sequence of DNA 9 , providing an opportunity to assess DNA methylat...

The variables associated with gastroesophageal reflux (GER) after peroral endoscopic myotomy (POEM) are largely unknown. This study aimed to: 1) identify the prevalence of reflux esophagitis and asymptomatic GER in patients who underwent POEM, and 2) evaluate patient and intraprocedural variables associated with post-POEM GER. All patients who underwent POEM and subsequent objective testing for GER (pH study with or without upper gastrointestinal [GI] endoscopy) at seven tertiary academic centers (one Asian, two US, four European) were included. Patients were divided into two groups: 1) DeMeester score ≥ 14.72 (cases) and 2) DeMeester score of< 14.72 (controls). Asymptomatic GER was defined as a patient with a DeMeester score ≥ 14.72 who was not consuming proton pump inhibitor (PPI). A total of 282 patients (female 48.2 %, Caucasian 84.8 %; mean body mass index 24.1 kg/m) were included. Clinical success was achieved in 94.3 % of patients. GER evaluation was completed after a median follow-up of 12 months (interquartile range 10 - 24 months). A DeMeester score of ≥ 14.72 was seen in 57.8 % of patients. Multivariable analysis revealed female sex to be the only independent association (odds ratio 1.69, 95 % confidence interval 1.04 - 2.74) with post-POEM GER. No intraprocedural variables were associated with GER. Upper GI endoscopy was available in 233 patients, 54 (23.2 %) of whom were noted to have reflux esophagitis (majority Los Angeles Grade A or B). GER was asymptomatic in 60.1 %. Post-POEM GER was seen in the majority of patients. No intraprocedural variables were identified to allow for potential alteration in procedural technique.

BACKGROUND AND STUDY AIMS: Motorized spiral enteroscopy (MSE) has been shown to be safe and effective for deep enteroscopy in studies with limited numbers of patients without previous abdominal surgery at expert centers. Aim of this study was to investigate the safety, efficacy, and learning curve associated with MSE in a real-life scenario with inclusion of patients after abdominal surgery and with altered anatomy. PATIENTS AND METHODS: Patients with indications for deep enteroscopy were enrolled in a prospective observational multicenter study. Primary objective: serious adverse event rate (SAE); Secondary objectives: diagnostic and therapeutic yield, procedural success, time, insertion depth. Data analysis was subdivided into training and core (post-training) study phases at centers with different levels of MSE experience. RESULTS: Two hundred ninety-eight patients (120 females; median age 68 years; 19-92) were enrolled. 21.5% (n=54) had previous abdominal surgery, 10.0% (n=25) had surgically altered anatomy. Overall, SAEs occurred in 2.3% (7/298) 95%CI 0.9%-4.8%. The SAE rate was 2.0% (5/251) in the core group and 4.3% (2/47) in the training group and was not increased after abdominal surgery (1.9%). Total enteroscopy was achieved in half of the patients with planned total enteroscopy (n=42). In 295/337 procedures (87.5%) the anatomical region of interest could be reached. CONCLUSIONS: This prospective multicenter study showed that MSE was feasible and safe in a large cohort of patients in a real-life setting after a short learning curve. MSE was shown to be feasible in postsurgical patients and patients with altered anatomy without AE rate increase. NCT03955081 (clinicaltrials.gov)

No self-reported symptoms presented by outpatients without CRC risk factors can be used accurately to identify patients with CRC with certainty. For clinical purposes self-reported symptoms seems thus not to be a useful accurate tool to distinguish between symptomatic outpatients with and without CRC.

POEM has a place in the treatment of esophageal achalasia in patients with a prior Heller myotomy and persistent symptoms as it is a safe procedure with acceptable long-term results.