Abstract In this paper we demonstrate that matrix-assisted laser desorption ionization/time-of-flight (MALDI-TOF) mass spectrometry can be used to rapidly detect occult blood in human feces. The water-soluble hemoglobins, which are the most predominant proteins found in blood, were used as protein biomarkers for the presence of occult blood. The proteins were best extracted from feces using a small amount of pure water and then separated from the feces through centrifugation. We found that saturated 4-hydroxy-£\-cyanocinnamic acid (£\-CHC) solution was the best MALDI matrix for hemoglobin analysis; this matrix was mixed with the aqueous solution extracted from the feces at a volumetric ratio of 1:1. Although the MALDI-TOF MS results obtained using real samples were consistent with those provided through conventional chemical analysis, the detection limit of occult blood (0.1¡V1 £gg/mg of feces) in feces when using MALDI MS was approximately 10¡V100 times lower than that of the conventional approach. In addition, materials that commonly interfere with the conventional chemical assaying of occult blood in feces¡Xsuch as foods containing animal blood¡Xdo not interfere with the detection of the hemoglobin biomarkers during MALDI-TOF MS analysis.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains ix, 98 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 92-98).

This thesis examines the benefits and costs of screening for colorectal cancer in the context of an organised population screening programme. It uses microsimulation modelling to derive an optimally cost-effective screening protocol for various combinations of the available screening tests. ¶ First a mathematical model for the natural history of colorectal cancer is derived, based on analyses of Australian population and hospital-based cancer registries combined with data from published studies. Then a model for population based screening is derived based mainly on data from published screening studies, including the four major published randomised controlled trials of faecal occult blood test (FOBT) screening. These two models are used to simulate the application of a screening programme to the Australian population. The simulations are applied to a period of 40 years following 1990 (the study’s base year), with both costs and benefits discounted back to the base year at an annual rate of 3%.¶ The models are applied to simulating a population screening programme based on FOBT with a colonoscopy follow up of positive tests. This simulation suggests that the optimal application of such a programme would be to offer annual screening to people aged 50 to 84 years. Such a programme would lead to a cumulative fall in years of life lost to colorectal cancer (YLL) of 28.5% at a cost per year of life saved (YLS) of $8,987. These costs and benefits are consistent with those arising from other currently funded health interventions. They are also consistent with the cost per YLS which Australian governments appear willing to pay for health interventions when justified on the basis of cost-effectiveness. The fall in colorectal cancer deaths from this screening programme should be first detectable by a national monitoring system after around three years of screening. However the full benefits from screening would not be realised before around 30 years of screening.¶ These simulations are based on the standard guaiac FOBT, but the results suggest that significant cost-effective gains could be made by using the newer immunochemical FOBT. Further cost-effect gains could be made by offering sigmoidoscopy every five years in addition to annual FOBT.¶ The models are then applied to simulating population screening programmes using colonoscopy and sigmoidoscopy as primary screening tools. Offering colonoscopy every ten years to all people aged from 45 to 85 leads to an overall fall in cumulative YLL of 37.6%, at a cost of $15,585 per YLS. Offering sigmoidoscopy every three years to all people aged 40 to 85 leads to an overall fall in cumulative YLL of 29.1%, at a cost of $4,862 per YLS. Both of these cost and benefit results are also consistent with the cost per YLS which Australian governments appear willing to pay. The fall in deaths with colonoscopy screening would also be detectable after three years of screening but the fall with sigmoidoscopy screening would not be detectable until after six years of screening. Sigmoidoscopy would need around 35 years of screening to reach its potential gains while colonoscopy screening would not reach its full potential during the 40 year screening period.¶ Finally the models are applied to targeting people at higher risk of cancer. The results show that offering colonoscopy every five years to people at higher risk because of a family history of colorectal cancer is a cost-effective addition to the annual FOBT screening programme.¶ An earlier version of chapter two of this thesis has been published as Stevenson CE 1995. Statistical models for cancer screening. Statistical Methods in Medical Research; 4: 19–23.¶ An expanded version of chapter two, along with parts of chapter one, has been published as Stevenson CE 1998. Models of screening. In: Encyclopedia of Biostatistics. Armitage P, Colton T, eds. John Wiley and Sons Ltd, pp 3999–4022.

Chapter 1. Deciphering the toxicity of Helicobacter pylori clinical isolates from gastric diseases patients using MALDI-TOF/MS and multivariate analysis. Helicobacter pylori (H. pyloyi) infection is associated with gastric diseases such as gastric polyp, chronic gastritis, gastric ulcer, gastric cancer, etc. In fact, most of the people infected not have the symptoms of gastric diseases due to the high degree of variability of gene with H. pyloyi and the specific immune responses of the hosts. In order to investigate the relationship between H.pylori and gastric diseases, the clinical strains of H. pylori isolated from patients from nine gastric diseases were extracted from the optimized extraction and analysis by MALDI-TOF/MS, then the high reproducible spectra were combined with multivariate statistical analysis including Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), Discriminant Analysis (DA) . In the result of PCA, there is no specific potential marker to discriminate the clinical strains to nine gastric diseases. In the result of HCA, the strains from different gastric diseases were clustered together means they have the similarity of the protein and metabolite. In the result of DA, the strains from gastric and non-gastric cancer were discriminanted by the discriminant function composed of thirty-eight discriminant variables in the spectra. This discriminant function would be confirmed by other clinical strains isolated from gastric diseases patients in the future and then would help to predict the the similarity of the protein and metabolite of the strains isolated from the gastric diseases patients whether gastric cancer or not. Chapter 2. Biomarker discovery in the stools of gastric cancer patients using MALDI-TOF/MS. According to the statistics of Republic 100 years from the Department of Health, cancer was the first of the ten lesding to death. With the modern change of eatiog habbits, gastrointestinal cancer has increased steadily. Gastrointestinal cancer accompanied occult gastrointestinal bleeding, and it is commonly detected by the fecal occult blood test (FOB). FOB including Guaiac-based fecal occult-blood test and immunochemical tests. Guaiac-based fecal occult-blood tests make use of the pseudoperoxidase activity of heme, and the reagent turns blue after oxidation by oxidants or peroxidases in the presence of an oxygen donor such as hydrogen peroxide, so it would have the potential of false-positive result. Immunochemical tests, which use antibodies detect against human hemoglobin with great sensitivity, but the tests are limited by loss of hemoglobin antigenicity at room temperature and require processing in a laboratory. In order to decrease the false-positive of detecting heme and decreasing the cost of the detection against hemoglobin in stools, in the study, we ues the distill water to extract the heme (m/z 616) and hemoglobin in stools and analysis with the reflectron and linear mode of MALDI-TOF/MS. In this study, at first, we used the stimulated stomach acid decomposing the hemoglobin to release the heme, to stimulate the gastrointestinal bleeding. Second, we used the distill water to extract the hemoglobin in stools, and detected by the linear mode of MALDI-TOF/MS, and the detection limit of MALDI-TOF/MS against hemoglobin in stool was better than the immunochemical tests. Third, the same strategy was applied to fifty-nine patients (including nineteen esophageal cancer patients, twenty gastric cancer patients and colorectal cancer patients) stools to detect heme and hemoglobin by MALDI-TOF/MS and the results were compared with the fecal occult blood test. In the detection of heme, MALDI-TOF/MS had not detect heme, but the Guaiac-based fecal occult-blood test had detected, it would be that the stools had the oxidants (not heme) to react the reagent. In addition, MALDI-TOF/MS had detected heme, but the Guaiac-based fecal occult-blood test had no results, those cases would be catched up in the future. In the detection of hemoglobin, using immunochemical tests to be the reference index, MALDI-TOF/MS had the false-negative result might come from the complicated matrix effect of stools, so that the hemoglobin could not form the good crystalline with matrix CHCA. The false-positive results of MALDI-TOF/MS might come from the criteria of hemoglobin signal.

Colorectal cancer poses a serious threat to the health and well-being of individuals, especially those at high risk or over the age of 50. Gone undetected, colorectal cancer is often fatal, however, preventive screening greatly reduces the number of people who may develop this disease. The Centers for Disease Control and Prevention developed the Colorectal Cancer Screening Demonstration Program in 2005 to assess the feasibility of a national colorectal cancer screening program serving low-income and un- or underinsured populations. Qualitative case study data from the Colorectal Cancer Screening Demonstration Program evaluation were analyzed in order to examine the start-up experiences of two of the programs involved. Results from this multiple case study document program models and describe facilitators, challenges, and participant perception of the expected impact on screening behavior. Further research on program implementation is needed to understand how program models perform and impact behavior once screening begins.

In Australia, colorectal cancer (CRC) is the most common registrable cancer affecting both men and women, and the third most common cause of cancer deaths. Clinical data from randomised, controlled trials indicate that population-based screening utilising the faecal occult blood test (FOBT) can reduce mortality from this disease. However, high adherence rates with repeated testing are required to secure these outcomes. This study examines repeat adherence with FOBT screening in a rural community two years after a first screening round was conducted. Patients, aged 50 to 74 years, registered with four local general practices were mailed a FOBT kit with a letter of invitation from their general practitioner. Following the intervention, 119 telephone interviews were conducted with adherers and non-adherers to examine knowledge and attitudes related to screening. Compliance with screening was recorded and compared with first round-data. Participation in the screening program was modest. Of the 3,406 participants eligible for both screening rounds, 34.1% and 34.7% participated in rounds 1 and 2, respectively. A majority of participants (56.8%) did not adhere to either screening, a quarter (25.7%) participated in both rounds, and 17.5% participated in one of the two rounds. First-round adherence was the strongest predictor of second-round adherence (OR=16.29; 95% CI: 13.58, 19.53) with 75.2% of first-round adherers completing a FOBT in round 2. Females were also more likely to adhere in both rounds, although the difference between females and males decreased across rounds. Knowledge and attitudes differed between adherers and non-adherers and are discussed within the context of the major findings. Results from this trial indicate that achieving high levels of compliance in a national screening program will be challenging. Strategies to increase repeat adherence are suggested.

Orientador: Maria Isabel Pedreira de Freitas Ceribelli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T01:00:38Z (GMT). No. of bitstreams: 1 NegrideSousa_AnaClaudia_M.pdf: 10758939 bytes, checksum: 1e275b80f25f5c6d9e3ab12d3eee6c94 (MD5) Previous issue date: 2012 / Resumo: Lâminas e cabos de laringoscópios têm sido analisados evidenciando presença de sangue, fluídos corpóreos e microrganismos, podendo apresentar-se potencialmente contaminados durante seu uso clínico. A forma de utilização destes equipamentos na prática diária pode estar colocando o paciente e a equipe de saúde em risco devido à maneira como vem sendo feita sua limpeza e desinfecção. Neste estudo estabeleceu-se a hipótese de que a lâmina e o cabo de laringoscópio, prontos para serem usados no paciente, sejam potenciais fontes de contaminação. O objetivo geral foi determinar a presença de sangue e de microrganismos neste equipamento. Foram analisados cabos e lâminas de laringoscópios, prontos para uso, em dois hospitais universitários públicos do interior de São Paulo. A amostra foi definida considerandose os equipamentos prontos para uso nas seções selecionadas em cada hospital, totalizando para análise microbiológica na Instituição I, 42 lâminas e na Instituição II 41 lâminas. Para a fase de presença de sangue, respectivamente, foram avaliadas 48 e 50 amostras, sendo estes distribuidos entre lâminas e cabos de laringoscópios. As análises microbiológicas foram realizadas no Laboratório de Microbiologia da Divisão de Patologia Clínica da Instituição II, utilizando-se técnicas laboratoriais quantitativas e qualitativas. Para a identificação de sangue oculto foi utilizado o teste para o monitoramento de sua presença em superfícies com metodologia em conformidade com a norma EM ISO 15883, com nome comercial de HemoCheck-S®. Os dados foram analisados descritivamente. Os resultados para o teste de sangue oculto nas lâminas e cabos dos laringoscópios foram de 14,3% e 46,0% positivos na Intituição I e II, respectivamente. Para o crescimento de microrganismos na Instituição I o resultado foi positivo para 76,2% das amostras, na Instituição II, um total de 92,7%. Na contagem de UFC mais de 101 UFC foram encontradas em 31,3% amostras na Instiutição I e na Instituição II em 44,7%. O estudo concluiu que a lâminas e o cabos dos laringoscópios nestas duas intituições pesquisadas oferecem riscos aos pacientes, apresentando crescimento de microrganismos e presença de sangue oculto. Urge providências para que seja possível sua utilização, garantindo-se a segurança dos pacientes e dos profissionais que tem contato direto com este equipamento / Abstract: Laryngoscope blades and handles have been analyzed showing the presence of blood, body fluids and microorganisms, which may present as potentially contaminated during its clinical use. The daily practical utilization of devices can be exposing patients and health professionals to risk, due to ineffective cleaning and disinfecting methods. This study established the hypothesis that the laryngoscope blade and handle, when ready to use, are potential sources of contamination. Thus, the overall objective is to determine the presence of microorganisms and blood in the equipment. Laryngoscope handles and blades was analyzed, when ready to use, in two public school hospital in the country side of São Paulo. The sample size was defined considering the equipment readiness in specific areas of each hospital, summarizing 42 blades at institution I and 41 blades at institution II for microbiological analysis. For the presence of blood testing phase, 48 and 50 samples were evaluated respectively, considering laryngoscope blades and handles. Microbiological analysis was performed at the Laboratory of Microbiology, Division of Clinical Pathology, Institution II, using qualitative and quantitative laboratory techniques. For occult blood finding, the surface test methodology in accordance with standard EN ISO 15883 was used, commercial name HemoCheck-S ® and data was analyzed descriptively. The results for occult blood test in the blades and handles of laryngoscopes were positive for 14.3% and 46.0%, for institutions I and II, respectively. For microorganisms' growth test, institution I indicated positive to 76.2% of the samples and institution II showed positive for a total of 92.7% of the samples. For UFC counting, UFC higher than 101 UFC was found in 31.3% of samples for institution I and 44.7% for institution II. This study revealed that the laryngoscope blades and handles of two evaluated institutions shows risks to patients, indicating a growth of microorganisms and the presence of occult blood. Urgent steps should be taken to allow their utilization, guaranteeing the safety of patients and health professionals who have direct contact with this equipment / Mestrado / Enfermagem e Trabalho / Mestre em Ciências da Saúde

Orientador: Maria Aparecida Mesquita / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T07:52:26Z (GMT). No. of bitstreams: 1 Freitas_BiancaRosaViana_M.pdf: 1586958 bytes, checksum: d79cc5666f8ce8e1281b43dad83b32ba (MD5) Previous issue date: 2013 / Resumo: O câncer colorretal (CCR) tem uma alta mortalidade, que pode ser diminuída com o rastreamento da população de risco médio a partir dos 50 anos de idade. Além da detecção precoce do CCR, é importante que os métodos de rastreamento identifiquem a presença de adenomas avançados. Um dos procedimentos recomendados para o rastreamento populacional é a pesquisa de sangue oculto nas fezes, realizada anualmente. O método tradicional para essa pesquisa é o teste do guáiaco. Entretanto, esse método tem uma sensibilidade relativamente baixa para detectar o CCR, e muito baixa para detectar os adenomas avançados. Além disso, exige dos pacientes várias restrições dietéticas e medicamentosas. Mais recentemente, os dados da literatura têm sugerido que o método imunoquímico de pesquisa do sangue oculto fecal é uma alternativa mais eficaz que o teste do guáiaco, com a vantagem de não demandar restrições dietéticas para a sua realização. Entretanto, existem ainda discordâncias entre os autores quanto à acurácia do método. Além disso, na maior parte dos estudos os pacientes com resultados negativos para a pesquisa do sangue oculto fecal não foram submetidos à colonoscopia, o que impede a determinação da sensibilidade e especificidade do teste. No Brasil ainda não existem estudos com grandes casuísticas para avaliar o desempenho desse método na detecção do CCR e de adenomas avançados. Portanto, o objetivo desse estudo foi avaliar a sensibilidade e a especificidade da pesquisa do sangue oculto nas fezes pelo método imunoquímico na detecção do CCR e de adenomas avançados em comparação com os achados da colonoscopia. A população de estudo foi constituída pelos pacientes com agendamento para o exame de colonoscopia no Gastrocentro entre julho de 2009 e julho de 2010. Foi solicitado que trouxessem uma amostra de fezes no dia da reunião de orientação sobre o exame de colonoscopia, realizada sete dias antes da realização do exame. Ao final, 302 pacientes realizaram os dois exames, sendo 64,2% do sexo feminino e 35,8% do sexo masculino, com idade de 56 ± 14 anos. As principais indicações para a colonoscopia foram: seguimento pós-cirúrgico de pacientes com CCR, alteração do hábito intestinal e seguimento de pólipos. Quanto aos resultados da colonoscopia, o exame não demonstrou nenhuma anormalidade em 52% dos pacientes, enquanto que o principal achado foi a presença de pólipos em 24,5% dos pacientes. Nove (3%) pacientes apresentaram CCR e 11 (15%) apresentaram adenomas avançados. A comparação com os dados da colonoscopia mostrou que a pesquisa do sangue oculto nas fezes pelo método imunoquímico apresentou sensibilidade de 88,9% para detectar o CCR e de 63,6% para os adenomas avançados. A especificidade do teste tanto para CCR quanto para adenomas avançados foi de 87,6 %. Em conclusão, a pesquisa de sangue oculto nas fezes pelo método imunoquímico apresentou uma boa sensibilidade e especificidade para a detecção das neoplasias avançadas na população estudada, indicando que esse método pode ser um instrumento útil para os futuros programas de rastreamento no Brasil / Abstract: Colorectal cancer (CRC) has a high mortality, which can be reduced through the screening of average-risk population beginning at age 50 years. In addition to the early detection of CRC, it is important that screening methods to identify the presence of advanced adenomas. One of the recommended procedures for population screening is the fecal occult blood test held annually. The traditional method for this research is the guaiac test. However, this method has a relatively low sensitivity for detecting CRC and very low to detect advanced adenomas. In addition, the test requires dietary and medication restrictions. More recently, data from the literature have suggested that the immunochemical fecal occult blood test is a more effective alternative to the guaiac test, with the advantage that it does not require dietary restrictions. However, there are still disagreements among authors regarding the accuracy of the method. Furthermore, in most studies the patients with negative results for the fecal occult blood test did not undergo colonoscopy, and therefore sensitivity and specificity could not be calculated. In Brazil there are no studies with large samples to assess the accuracy of this method. Therefore the aim of this study was to evaluate the sensitivity and specificity of the immunochemical fecal occult blood test for the detection of CRC and advanced adenomas compared with the findings of colonoscopy. The study population was composed of patients scheduled for colonoscopy at Gastrocentro-Unicamp between July 2009 and July 2010. Patients were asked to bring a stool sample on the day of the educational session about colonoscopy, which takes place one week before the exam. At the end, 302 patients underwent both examinations, 64.2% were female and 35.8% male, with mean age 56 ± 14 years. The main indications for colonoscopy were: postoperative follow-up of patients with RCC, changes in bowel habits and follow-up of polyps. Regarding the results of the colonoscopy examination, no abnormality was found in 52% of patients, whereas the main finding was the precence of polyps in 24.% of patients. Nine (3%) of our patients had RCC, while 11 (15%) had advanced adenomas. The comparison with the data of colonoscopy showed that the immunochemical fecal occult blood test had a sensitivity of 88.9% to detect CCR and 63.6% for advanced adenomas. The specificity of the test for both CCR and advanced adenomas was 87.6%. In conclusion, the immunochemical fecal occult blood test showed good sensitivity and specificity for the detection of advanced neoplasia in our study population, indicating that this method can be a useful tool for future screening programs in Brazil / Mestrado / Clinica Medica / Mestra em Clínica Médica

A Cochrane review conducted a meta-analysis looking only at FOBT for colorectal cancer screening. This review, based on published and unpublished data from 5 controlled trials, demonstrated that 3-card home FOBT conferred a reduction in colorectal cancer mortality of 16% (relative risk [RR]=0.84; 95% confidence interval [CI], 0.77-0.92) and a number needed to screen of 1173 (95% CI, 741-2807) to prevent 1 death from colon cancer over a 10-year period. If adjusted for adherence to screening, the reduction in mortality increased to 23% (RR=0.77; 95% CI, 0.57-0.89). In addition, long-term follow up of one of the RCTs in the review showed a continued reduction in colorectal cancer mortality of 34% (RR=0.66; 95% CI, 0.54-0.81) in subjects adhering to the FOBT screening protocol over a 13-year interval. Overall mortality did not differ between the screened and unscreened groups. A systematic review performed for the US Preventive Services Task Force (USPSTF) incorporated more recent data on colorectal cancer screening including colonoscopy. This review reached similar conclusions as above. This review also looked at office FOBT performed after digital rectal exam. It is important to note that a single office FOBT has a lower sensitivity than 3-card home FOBT and its effectiveness for reducing colorectal cancer mortality was unknown at the time of the systematic review. A subsequent 2005 Veterans Affairs prospective cohort study found that the sensitivity for detecting advanced neoplasia was only 4.9% for digital FOBT, and negative results did not decrease the likelihood of advanced neoplasia. The USPSTF review did not find any screening trials of colonoscopy but analyzed data from the National Polyp Study and a case-control study to draw its conclusions. The review reported an odds ratio for colorectal cancer mortality for patients who had colonoscopy to be 0.43 (95% CI, 0.30-63). The USPSTF review also looked at the sensitivity and adverse effects of FOBT compared to colonoscopy. One-time 3-card home FOBT had a sensitivity of 30% to 40% for detecting cancer. The sensitivity of one-time colonoscopy was difficult to determine since it was the criterion standard examination, but it was estimated to be greater than 90%, with a risk of perforation of 1/2000. The USPSTF review found both screening strategies cost-effective (<$30,000 per additional life-year gained) compared to no screening. FOBT had a cost per life-year saved of $5691 to $17,805 compared with $9038 to $22,012 for colonoscopy performed every 10 years.

Background: Currently, participation in the NHS Bowel Cancer Screening Programme (NHSBCSP) is poor, with around half of all people invited returning their (FOBT) kits. The research programme aimed to investigate whether a general practitioner’s (GP) letter encouraging participation and a detailed leaflet explaining how to complete the (FOBT) included with the invitation materials would improve uptake. Methods: The research programme was divided into three phases which were designed to sequentially develop and evaluate the two interventions. The initial and second phases developed and refined the two interventions and the trial outcome measures with previous participants and stakeholder representatives. The final phase was a randomised 2x2 factorial trial conducted with people invited to screening in October 2009. Participants were randomised to either a GP’s endorsement letter and/or a detailed procedural leaflet with their FOBT kit. The primary outcome was verified participation in the NHSBCSP. Questionnaires were also used to evaluate participant perceptions of CRC screening and GPs views on involvement with the NHSBCSP. Results: The factorial trial demonstrated both the GP’s endorsement letter and the detailed procedural leaflet increased participation in the NHSBCSP. In the intention-to-treat analysis, participation improved by 6% for the detailed procedural leaflet and 5.8% for the GP endorsement letter 20 weeks after receipt of the FOBT kit. The random effects logistic regression model confirmed that there was no important interaction between the two interventions, and estimated an adjusted rate ratio of 1.11 (P=0.038) for the GP’s letter and 1.12 (P=0.029) for the leaflet. The per protocol analysis indicated that the insertion of an electronic GP’s signature on the endorsement letter was associated with increased participation (P=0.039). Conclusions: Including both an endorsement letter from each patient’s GP and a detailed procedural leaflet could increase participation in the NHSBCSP by around 10%, a relative improvement of 20% on the current participation rate. Both interventions were well-received by participants and there was minimal impact on GP workload.