Confocal Endomicroscopy of Colorectal Polyps

Confocal laser endomicroscopy (CLE) is one of several novel methods that provide real-time, high-resolution imaging at a micron scale via endoscopes. CLE has the potential to be a disruptive technology in that it can change the current algorithms that depend on biopsy to perform surveillance of high-risk conditions. Furthermore, it allows on-table decision making that has the potential to guide therapy in real time and reduce the need for repeated procedures. CLE and related technologies are often termed “virtual biopsy” as they simulate the images seen in traditional histology. However, the imaging of living tissue allows more than just pragmatic convenience; it also allows imaging of living tissue such as active capillary circulation, cellular death, and vascular and endothelial translocation, thus extending beyond what is capable in traditional biopsy. Immediate potential applications of CLE are to guide biopsy sampling in Barrett's esophagus and inflammatory bowel disease surveillance, evaluation of colorectal polyps, and intraductal imaging of the pancreas and bile duct. Data on these applications is rapidly emerging, and more is needed to clearly demonstrate the optimal applications of CLE. In this paper, we will focus on the role of CLE as applied to colorectal polyps detected during colonoscopy

Ab initio atomistic description of temperature-induced phase changes: The cases of zirconia and Ti-Y-co-doped zirconia

Zirconium dioxide, or zirconia, is a common and useful ceramic with a wide range of applications, from fuel cells to odontology. Its phase diagram is simple and well understood, having a structure which is monoclinic at temperatures up to 1500 K, tetragonal up to 2700 K and cubic up to 3000 K. Zirconia is rarely used in its pure form, being typically doped with Y2O3, MgO or TiO2, and in this regime its phase diagram becomes much more complex. In this context, ab initio molecular dynamics (AIMD) can provide a detailed atomistic description of the phase diagram of this system, accurately describing its stable phases and transition regions. In this work, 3 mol-% Y2O3 (3YSZ) crystals doped with different Ti contents were studied at the density-functional level. For Ti contents varying from 0 to 30 at%, a global search algorithm was first used to explore the 0 K potential-energy surface and determine the most stable sites for the added Ti atoms. It was found that, at low Ti compositions XTi, small TiO2 clusters form, followed by TiO2 channels and infinite TiO2 planes at larger XTi values, and that the highest stability is achieved at 9% Ti. AIMD simulations within the isothermal-isobaric NPT ensemble were then performed to characterize the temperature-dependent phase changes as a function of the Ti content, where it was found that the Ti-doped structures presented considerably smaller volume changes near the phase-change critical temperatures. These findings suggest that YSZ materials doped with a small amount of Ti are both energetically and kinetically more stable than the undoped counterparts, in the ideal proportion of 3% TiO2 for every 1% Y2O3 doping.Fil: Negreiros Ribeiro, Fábio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Ribeiro Ricci Lazar, Dolores. Comissao Nacional de Energia Nuclear. Centro de Lasers e Aplicacoes. Instituto de Pesquisas Energéticas e Nucleares; BrasilFil: Ussui, Valter. Comissao Nacional de Energia Nuclear. Centro de Lasers e Aplicacoes. Instituto de Pesquisas Energéticas e Nucleares; BrasilFil: De Lima, Nelson Batista. Comissao Nacional de Energia Nuclear. Centro de Lasers e Aplicacoes. Instituto de Pesquisas Energéticas e Nucleares; BrasilFil: Marchi, Juliana. Universidad Federal do Abc; BrasilFil: Dalpian, Gustavo Martini. Universidad Federal do Abc; Brasi

Study of colonoscopy-related tolerance parameters

Os exames endoscópicos são considerados procedimentos invasivos, desconfortáveis e estressantes. A colonoscopia, em virtude da necessidade de laxantes para o preparo do cólon, de sua complexidade técnica e do constrangimento devido à maior exposição, causa ansiedade, preocupação e preconceito. No entanto, a colonoscopia é, atualmente, o procedimento de escolha para investigação de enfermidades do intestino grosso de elevada acurácia e possibilidade de realização de procedimentos terapêuticos, mas requer elevada colaboração e tolerância dos pacientes. A tolerância pode ser interpretada de várias maneiras, como aceitação, nível de satisfação e conforto durante o exame, ou disposição para repetir o procedimento. Foi realizado no Centro de Diagnóstico do Serviço de Gastroenterologia Clínica do Instituto Central do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, um estudo observacional prospectivo, longitudinal, com o objetivo de avaliar o nível de tolerância do paciente submetido à colonoscopia e os fatores intervenientes na tolerância. No período de março a dezembro de 2008, foram avaliados 373 pacientes adultos consecutivos, submetidos à colonoscopia eletiva. Foram incluídos pacientes submetidos a exames eletivos, com idade acima de 18 anos, com compreensão e aceitação da entrevista e do procedimento, e que assinaram o termo de consentimento livre e esclarecido. Um inquérito foi aplicado antes, durante e após o exame, a partir de dois questionários: formulário do paciente, preenchido pelo médico pesquisador; e ficha de avaliação médica, preenchido pelos médicos pesquisador e executante. No presente estudo considerou-se tolerância como a disposição do paciente para repetir o exame. Esse questionamento foi aplicado imediatamente na pré-alta, com o indivíduo desperto e orientado, no mínimo duas horas após o procedimento. Os fatores avaliados no pré-exame, durante o exame e no pós-exame foram comparados entre o grupo de pacientes tolerantes e os não tolerantes. Noventa e um por cento dos pacientes avaliados mostraram-se tolerantes à colonoscopia. Maiores níveis de tolerância foram observados em pacientes do sexo masculino (p=0,005; OR=14,8), com idade entre 41 anos e 60 anos (p=0,003; OR=56,92), colaborativos durante o exame (p=0,013; OR=6,15) e que não apresentaram cólica durante o preparo intestinal (p=0,013; OR=5) ou dor abdominal após o procedimento (p=0,032; OR=3,25). Um dos fatores limitantes do presente estudo foi o desconhecimento da razão pela qual o paciente não faria novamente o exame. A diferente graduação dos médicos colonoscopistas, a inclusão de pacientes ambulatoriais e internados submetidos à cirurgia colorretal tornaram a amostra heterogênea, porém mais representativa da prática clínica. Nessa amostra, a dor abdominal associada à colonoscopia foi o elemento mais significativo na caracterização da tolerânciaEndoscopic assessments are considered invasive, uncomfortable and stressful procedures. The colonoscopy, due to the need for laxative use for colon preparation, its technical complexity and the embarrassment caused by privacy exposure, results in anxiety, concern and prejudice. However, the colonoscopy is currently the procedure of choice to investigate large bowel disorders, due to its high accuracy and the possibility of performing therapeutic procedures during the examination, but it requires a high degree of collaboration and compliance on the part of the patient. Tolerance can be interpreted in different ways, such as acceptance, level of satisfaction, and comfort during the examination, or willingness to have the procedure repeated. A prospective observational study was carried out at the Diagnostic Center of the Service of Clinical Gastroenterology of Instituto Central of Hospital das Clínicas of the School of Medicine of the University of São Paulo (HCFMUSP), aiming at evaluating the level of tolerance of patients submitted to colonoscopy and the factors that interfere with this tolerance. A total of 373 consecutive adult patients submitted to elective colonoscopy were studied from March to December 2008. The inclusion criteria consisted of patients submitted to elective examinations, aged 18 and older, which understood and agreed with the interview and the procedure and signed the Free and Informed Consent Form. A survey was applied before, during and after the examination, based on two questionnaires: the patients questionnaire, filled out by the medical researcher and the medical assessment file, filled out by the medical researcher and the attending physician. The present study considered the patients tolerance as the willingness to have the procedure repeated. This survey was applied immediately at the pre-hospital discharge, when the patient was conscious and oriented, at least two hours after the procedure. The factors assessed before, during and after the examination were compared between the groups of compliant and non-compliant patients. A total of 91% of the assessed patients showed to be compliant with the colonoscopy. Higher levels of tolerance were observed in male patients (p=0.005; OR=14.8), aged 41 to 60 years (p=0.003; OR=56.92), who collaborated during the examination (p=0.013; OR=6.15) and did not have colic during the intestinal preparation (p=0.013; OR=5) or abdominal pain after the procedure (p=0.032; OR=3.25). One limitation of the present study was the lack of information on why the patient would not have the procedure repeated. The varied degrees of skill presented by colonoscopists, the inclusion of outpatients and inpatients submitted to colorectal surgery made the sample a more heterogeneous one, albeit more representative of clinical practice. In this sample, abdominal pain associated with the colonoscopy was the most significant element in the characterization of toleranc

Portal Cavernoma Mimicking Pancreatic Malignancy

Portal cavernoma colangiopathy (PCC) is an uncommon cause of portal hypertension, and it is an important differential diagnosis of pancreatic malignancy given the expanded network of collateral vessels. On imaging studies, portal cavernoma can be seen as a hypoechoic mass, possibly associated with distal common bile duct obstruction. Most cases occur in non-cirrhotic patients. During the symptomatic phase, these patients carry a high-risk of complications related to sustained biliary obstruction. We report a unique patient with obstructive jaundice and a presumed pancreatic mass that proved to be a portal cavernoma complicated by PCC in the setting of nodular regenerative hyperplasia of the liver