Forensic luminol reaction for detecting fecal occult blood in experimental mice.
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ABSTRACT:
SUBMITTER: Park AM
PROVIDER: S-EPMC6353634 | biostudies-literature | 2018 Oct
REPOSITORIES: biostudies-literature
Publications
Forensic luminol reaction for detecting fecal occult blood in experimental mice.
BioTechniques 20180824 4
Fecal occult blood (FOB) is a sign of gastrointestinal diseases, such as intestinal ulcers and colorectal cancer. In experimental animal studies, there is no standard method to detect FOB. Here, we present a simple protocol to detect FOB in mice, using the Luminol Reaction Experiment Kit<sup>®</sup> that was originally designed to detect bloodstains at a crime scene in criminal forensics. To obtain positive control bloody feces, we used an indomethacin-induced intestinal ulcer model in mice. By ...[more]
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Project description:BACKGROUND: Many patients with a positive fecal occult blood test (FOBT) do not undergo follow-up evaluations. OBJECTIVE: To identify the rate of follow-up colonoscopy following a positive FOBT and determine underlying reasons for lack of follow-up. DESIGN: It is a retrospective chart review. PARTICIPANTS: The subject group consisted of 1,041 adults with positive FOBTs within a large physician group practice from 2004 to 2006. MEASUREMENTS: We collected data on reasons for ordering FOBT, presence of prior colonoscopy, completed evaluations, and results of follow-up tests. We fit a multivariable logistic regression model to identify predictors of undergoing follow-up colonoscopy. RESULTS: Most positive FOBTs were ordered for routine colorectal cancer screening (76%), or evaluation of anemia (13%) or rectal bleeding (7%). Colonoscopy was completed in 62% of cases, with one-third of these procedures identifying a colorectal adenoma (29%) or cancer (4%). Factors associated with higher rates of follow-up colonoscopy included obtaining the FOBT for routine colorectal screening (odds ratio (OR) 1.59, 95% confidence interval (CI) 1.11-2.29) and consultation with gastroenterology (OR 1.99, 95% CI 1.46-2.72). Patients were less likely to undergo colonoscopy if they were older than 80 years old (OR 0.54, 95% CI 0.31-0.92), younger than 50 years old (OR 0.44, 95% CI 0.28-0.70), uninsured (OR 0.50, 95% CI 0.27-0.93), or had undergone colonoscopy within the prior five years (OR 0.32, 95% CI 0.23-0.44). CONCLUSIONS: Clinical decisions and patient factors available at the time of ordering an FOBT impact performance of colonoscopy. Targeting physicians' understanding of the use of this test may improve follow-up and reduce inappropriate use of this test.
| S-EPMC2642561 | biostudies-other
Project description:Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths in the United States. Randomized controlled trials have shown that annual screening fecal occult blood testing (FOBT) reduces CRC mortality and incidence. However, patient compliance with FOBT is low.To determine whether a mailed educational reminder increases FOBT card return rates and to examine predictors of FOBT compliance.Blinded, randomized, controlled trial at the Veteran Affairs Medical Center, San Diego, California.Seven hundred and seventy-five consecutive patients > or =50 years of age referred by their primary care physicians for FOBT.Patients were randomly assigned to the usual care group or the intervention group. Ten days after picking up the FOBT cards, a 1-page reminder with information related to CRC screening was mailed to the intervention group only.The primary outcome was proportion of returned FOBT cards after 6 months. Patient demographic, clinical characteristics and prior FOBT completed were collected for multivariate regression analysis.At 6 months after card distribution, 64.6% of patients in the intervention group returned cards compared with 48.4% in the control group (P < 0.001). Patients who received a mailed reminder (OR 2.02; 95% CI: 1.48-2.74) or have a prior history of returning the FOBT cards (OR 1.87; 95% CI: 1.29-2.70) were more likely to return the FOBT cards. Patients with current or recent illicit drug use were less likely to return the FOBT cards (OR 0.26; 95% CI: 0.13-0.50).A simple mailed educational reminder significantly increases compliance with FOBT for CRC screening.
| S-EPMC2771232 | biostudies-literature
Project description:Screening with fecal occult blood tests (FOBT) reduces colorectal cancer mortality. Failure to complete repeat tests may compromise screening effectiveness. We conducted a systematic review of repeat FOBT across diverse health care settings. We searched MEDLINE, Embase, and the Cochrane Library for studies published from 1997 to 2017 and reported repeat FOBT over ?2 screening rounds. Studies (n = 27 reported in 35 articles) measured repeat FOBT as (i) proportion of Round 1 participants completing repeat FOBT in Round 2; (ii) proportion completing two, consecutive FOBT; or (iii) proportion completing ?3 rounds. Among those who completed FOBT in Round 1, 24.6% to 89.6% completed repeat FOBT in Round 2 [median: 82.0%; interquartile range (IQR): 73.7%-84.6%]. The proportion completing FOBT in two rounds ranged from 16.4% to 80.0% (median: 46.6%; IQR: 40.5%-50.0%), and in studies examining ?3 rounds, repeat FOBT ranged from 0.8% to 64.1% (median: 39.2%; IQR: 19.7%-49.4%). Repeat FOBT appeared higher in mailed outreach (69.1%-89.6%) compared with opportunistic screening (24.6%-48.6%). Few studies examined correlates of repeat FOBT. In summary, we observed a wide prevalence of repeat FOBT, and prevalence generally declined in successive screening rounds. Interventions that increase and maintain participation in FOBT are needed to optimize effectiveness of this screening strategy.
| S-EPMC7007334 | biostudies-literature
Project description:BackgroundThe ColonCancerCheck screening program for colorectal cancer (CRC) in Ontario, Canada, is considering switching from biennial guaiac fecal occult blood test (gFOBT) screening between age 50-74 years to the more sensitive, but also less specific fecal immunochemical test (FIT). The aim of this study is to estimate whether the additional benefits of FIT screening compared to gFOBT outweigh the additional costs and harms.MethodsWe used microsimulation modeling to estimate quality adjusted life years (QALYs) gained and costs of gFOBT and FIT, compared to no screening, in a cohort of screening participants. We compared strategies with various age ranges, screening intervals, and cut-off levels for FIT. Cost-efficient strategies were determined for various levels of available colonoscopy capacity.ResultsCompared to no screening, biennial gFOBT screening between age 50-74 years provided 20 QALYs at a cost of CAN$200,900 per 1,000 participants, and required 17 colonoscopies per 1,000 participants per year. FIT screening was more effective and less costly. For the same level of colonoscopy requirement, biennial FIT (with a high cut-off level of 200 ng Hb/ml) between age 50-74 years provided 11 extra QALYs gained while saving CAN$333,300 per 1000 participants, compared to gFOBT. Without restrictions in colonoscopy capacity, FIT (with a low cut-off level of 50 ng Hb/ml) every year between age 45-80 years was the most cost-effective strategy providing 27 extra QALYs gained per 1000 participants, while saving CAN$448,300.InterpretationCompared to gFOBT screening, switching to FIT at a high cut-off level could increase the health benefits of a CRC screening program without considerably increasing colonoscopy demand.
| S-EPMC5351837 | biostudies-literature
Project description:Fecal occult blood testing (FOBT) has historically relied on methods to detect hemoglobin with no fundamental innovations in decades.To examine microRNA (miRNA) as a new marker class for FOBT.Candidate miRNA markers were identified by small RNA sequencing of human whole blood compared to colorectal epithelia. Markers were tested in human blood cell subsets and blood from non-human species. We assessed assay linearity in blood spiking and marker stability in stool over incubation experiments. Levels of candidate erythrocyte markers were explored in stools from colorectal cancer (CRC) cases and controls.Based on small RNA sequencing and validation RT-qPCR, expression level of each of the top blood-enriched markers (hsa-miR-144-3p, 144-5p, 451a, 486-5p, 363-3p, 20b-5p) could perfectly discriminate blood from colorectal epithelia. All six markers arose from and showed specificity to human erythrocytes. Marker levels increased linearly with erythrocyte concentration in saline or stool and demonstrated a broader dynamic range than did immunochemical test for hemoglobin. Degradation of markers occurred in stool but was reduced with preservative buffers. Erythrocyte marker candidates for stool testing were selected in an exploratory set of stools (20 CRC, 40 normal). Candidates were then further tested in a feasibility set (29 CRC, 31 advanced adenoma, and 115 normal); a miRNA panel (hsa-miR-451a, 144-5p, and 200b-3p as normalizer) yielded an AUC of 0.89 (95% CI 0.82-0.95, P < .0001) for CRC.A novel miRNA-based approach accurately quantifies fecal blood levels over a broad, clinically relevant range.
| S-EPMC6021130 | biostudies-other
Project description:AimCurrent fecal screening tools for colorectal cancer (CRC), such as fecal occult blood tests (FOBT), are limited by their low sensitivity. Calgranulin B (CALB) was previously reported as a candidate fecal marker for CRC. This study investigated whether a combination of the FOBT and fecal CALB has increased sensitivity and specificity for a diagnosis of CRC.Materials and methodsPatients with CRC (n = 175), and healthy individuals (controls; n = 151) were enrolled into the development (81 cases and 51 controls) and validation (94 cases and 100 controls) sets. Stool samples were collected before bowel preparation. CALB levels were determined by western blotting. FOBT and fecal CALB results were used to develop a predictive model based on logistic regression analysis. The benefit of adding CALB to a model with only FOBT was evaluated as an increased area under the receiver operating curve (AUC), partial AUC, and reclassification improvement (RI) in cases and controls, and net reclassification improvement (NRI).ResultsMean CALB level was significantly higher in CRC patients than in controls (P<0.001). CALB was not associated with tumor stage or cancer site, but positivity on the FOBT was significantly higher in advanced than in earlier tumor stages. At a specificity of 90%, the cross-validated AUC and sensitivity were 89.81% and 82.72%, respectively, in the development set, and 92.74% and 79.79%, respectively, in the validation set. The incremental benefit of adding CALB to the model, as shown by the increase in AUC, had a p-value of 0.0499. RI in cases and controls and NRI all revealed that adding CALB significantly improved the prediction model.ConclusionA predictive model using a combination of FOBT and CALB may have greater sensitivity and specificity and AUC for predicting CRC than models using a single marker.
| S-EPMC4154865 | biostudies-literature
Project description:There is no guideline defining the optimal time from a positive screening fecal occult blood test to follow-up colonoscopy. We reviewed records of 231 consecutive primary care patients who received a colonoscopy within 18 months of a positive fecal occult blood test. We examined the relationship between time to colonoscopy and risk of neoplasia on colonoscopy using a logistic regression analysis adjusting for potential confounders such as age, race, and gender. The mean time to colonoscopy was 236 days. Longer time to colonoscopy (OR = 1.10, P = 0.01) and older age (OR 1.04, P = 0.01) were associated with higher odds of neoplasia. The association of time with advanced neoplasia was positive, but not statistically significant (OR 1.07, P = 0.14). In this study, a longer interval to colonoscopy after fecal occult blood test was associated with an increased risk of neoplasia. Determining the optimal interval for follow-up is desirable and will require larger studies.
| S-EPMC3726721 | biostudies-literature
Project description:ObjectiveThe aim of this study is to compare the uptake of three mailed high-sensitivity fecal occult blood tests (FOBTs).MethodsWe conducted a parallel 3-arm randomized controlled trial in an integrated healthcare delivery system in Washington State. From January 2010 through February 2011, automated data were used to identify potentially eligible patients aged 50-74 due for colorectal cancer screening. Participants were mailed one of three FOBT kits (1-sample OC-Auto® fecal immunochemical test [FIT], 2-sample InSure® FIT, or 3-sample guaiac Hemoccult SENSA®), instructions, and a postage-paid return envelope. We performed a modified intent-to-treat analysis with return of any FOBT within 6 months of randomization as the primary outcome.ResultsOf the 9922 people invited, 2873 returned surveys, 2263 were randomized, and 2234 were analyzed. FOBTs were returned by 1431 participants. At 6 months post-randomization, the proportions screened by any FOBT were 0.69 (95% confidence interval [CI] 0.66-0.72) for the OC-Auto arm, 0.64 (95% CI: 0.61-0.68) for the InSure arm, and 0.61 (95% CI: 0.58-0.65) for the Hemoccult SENSA arm (P<0.001 for any difference). Pairwise comparisons showed significant differences between the OC-Auto group and each of the other groups after correction for multiple comparisons.ConclusionUptake of mailed FOBT kits varies by kit type.
| S-EPMC3856243 | biostudies-literature
Project description:Calprotectin is a calcium-binding cytoplasmic protein found in neutrophils and increasingly used as a marker of bowel inflammation. Fecal occult blood (FOB) is also a dependable indicator of bowel morbidity. The objective of our study was to determine the applicability of these tests as surrogate markers of Schistosoma mansoni intestinal morbidity before and after treatment with praziquantel (PZQ).216 children (ages 3-9 years old) from Buliisa District in Lake Albert, Uganda were examined and treated with PZQ at baseline in October 2012 with 211 of them re-examined 24 days later for S. mansoni and other soil transmitted helminths (STH). POC calprotectin and FOB assays were performed at both time points on a subset of children. Associations between the test results and infection were analysed by logistic regression.Fecal calprotectin concentrations of 150-300 µg/g were associated with S. mansoni egg patent infection both at baseline and follow up (OR: 12.5 P = 0.05; OR: 6.8 P = 0.02). FOB had a very strong association with baseline anemia (OR: 9.2 P = 0.03) and medium and high egg intensity schistosomiasis at follow up (OR: 6.6 P = 0.03; OR: 51.3 P = 0.003). Both tests were strongly associated with heavy intensity S. mansoni infections. There was a significant decrease in FOB and calprotectin test positivity after PZQ treatment in those children who had egg patent schistosomiasis at baseline.Both FOB and calprotectin rapid assays were found to correlate positively and strongly with egg patent S. mansoni infection with a positive ameloriation response after PZQ treatment indicative of short term reversion of morbidity. Both tests were appropriate for use in the field with excellent operational performance and reliability. Due to its lower-cost which makes its scale-up of use affordable, FOB could be immediately adopted as a monitoring tool for PC campaigns for efficacy evaluation before and after treatment.
| S-EPMC3828154 | biostudies-other
Project description:Effective methods are needed to collect fecal samples from children for large-scale microbiota studies. Stool collected on fecal occult blood test (FOBT) cards that can be mailed provides an effective solution; however, the quality of sequencing resulting from this method is unknown. The aim of this study is to compare microbiota metrics of 16S ribosomal RNA (rRNA) gene sequencing from stool and meconium collected on FOBT cards with stool collected in an Eppendorf tube (ET) under different conditions.Eight stool samples from children in diapers aged 0 month-2 years and three meconium samples were collected and stored as follows: (1) ??2 days at room temperature (RT) in an ET, (2) 7 days at -?80 °C in an ET, (3) 3-5 days at RT on a FOBT card, (4) 7 days at RT on a FOBT card, and (5) 7 days at -?80 °C on a FOBT card. Samples stored at -?80 °C were frozen immediately. Each specimen/condition underwent 16S rRNA gene sequencing with replicates on the Illumina MiSeq. Alpha and beta diversity measures and relative abundance of major phyla were compared between storage conditions and container (ET vs. FOBT card), with pairwise comparison between different storage conditions and the "standard" of 7 days at -?80 °C in an ET and fresh stool in an ET.Stool samples clustered mainly by individual diaper (P < 10-5, Adonis), rather than by storage condition (P = 0.42) or container (P = 0.16). However, meconium samples clustered more by container (P = 0.002) than by individual diaper (P = 0.009) and storage condition (P = 0.02). Additionally, there were no differences in alpha diversity measures and relative abundance of major phyla after Bonferroni correction between stool stored on a FOBT card at RT for 7 days with stool stored in an ET tube at -?80 °C; differences in alpha diversity were seen however when compared to fresh stool in an ET. Overall, based on the intraclass correlation coefficient (ICC), the different storage containers/conditions are reliable in preserving the microbial memberships and slightly less reliable in preserving the alpha diversity and relative microbial composition of infant stool.Acknowledging certain limitations, FOBT cards may be a useful tool in large-scale stool microbiota studies in children requiring outpatient follow-up where only small amounts of stool can be obtained, but should not be used when studying meconium.
| S-EPMC5583988 | biostudies-literature