Background & Aims Epidemiology studies have shown that obesity increases risk for colorectal cancer (CRC). We investigated the contribution of obesity-induced increases in levels of tumor necrosis ...factor (TNF)-α and hyperinsulinemia to the development of CRC in mice. Methods Lean and obese mice (C57BL6/J and ob/ob ) were given a combination of azoxymethane and dextran sulfate sodium, which led to the development of CRC; lean and obese severe combined immunodeficient mice were injected with HT-29 cells. We analyzed the roles of TNF-α and insulin in the development of obesity-mediated CRC using immunoblot, immunohistochemical, and apoptosis assays. Results Genetic- and diet-induced obesity increased the incidence and size of tumors that developed after administration of azoxymethane and dextran sulfate sodium, compared with lean mice. HT-29 xenograft tumors grew more rapidly in obese than lean mice. Neutralization of TNF-α reduced activation of c-Jun N-terminal kinase, IκB kinase, and the phosphatidylinositol 3-kinase–Akt–mammalian target of rapamycin signaling pathway; it also reduced the growth and development of tumors in obese mice. Reducing levels of insulin levels had no effect on tumor growth in obese mice. Conclusions TNF-α contributes to colon tumor growth in obese mice. Reagents that inhibit TNF-α might prevent the development or progression of CRC in obese individuals.
This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).
This article has been retracted at the request of the ...Editor-in-Chief and Deputy Editor-in-Chief following an investigation into the data that were presented in several figures within the article.
A number of images used in this article are believed to be duplicated images. The authors stated that they inadvertently inserted images of the wrong blots in several of the figures, resulting in the duplications; however, they did not address all of the concerns raised. Because the editors were no longer confident in the conclusions of the article based on these incorrect data, a decision was made to retract the paper.
All authors have been notified of this decision. The University of Campinas (UNICAMP) in São Paulo, Brazil was contacted regarding these concerns, but to date the journal has received no response.
DNA repair mechanisms are responsible for maintaining the integrity of DNA and are essential to life. However, our knowledge of DNA repair mechanisms is based on model organisms such as Escherichia ...coli, and little is known about free living and uncultured microorganisms. In this study, a functional screening was applied in a metagenomic library with the goal of discovering new genes involved in the maintenance of genomic integrity. One clone was identified and the sequence analysis showed an open reading frame homolog to a hypothetical protein annotated as a member of the Exo_Endo_Phos superfamily. This novel enzyme shows 3'-5' exonuclease activity on single and double strand DNA substrates and it is divalent metal-dependent, EDTA-sensitive and salt resistant. The clone carrying the hypothetical ORF was able to complement strains deficient in recombination or base excision repair, suggesting that the new enzyme may be acting on the repair of single strand breaks with 3' blockers, which are substrates for these repair pathways. Because this is the first report of an enzyme obtained from a metagenomic approach showing exonuclease activity, it was named ExoMeg1. The metagenomic approach has proved to be a useful tool for identifying new genes of uncultured microorganisms.
Measurements of CFTR function in rectal biopsies ex vivo have been used for diagnosis and prognosis of Cystic Fibrosis (CF) disease. Here, we aimed to evaluate this procedure regarding: i) viability ...of the rectal specimens obtained by biopsy forceps for ex vivo bioelectrical and biochemical laboratory analyses; and ii) overall assessment (comfort, invasiveness, pain, sedation requirement, etc.) of the rectal forceps biopsy procedure from the patients perspective to assess its feasibility as an outcome measure in clinical trials.
We compared three bowel preparation solutions (NaCl 0.9%, glycerol 12%, mannitol), and two biopsy forceps (standard and jumbo) in 580 rectal specimens from 132 individuals (CF and non-CF). Assessment of the overall rectal biopsy procedure (obtained by biopsy forceps) by patients was carried out by telephone surveys to 75 individuals who underwent the sigmoidoscopy procedure.
Integrity and friability of the tissue specimens correlate with their transepithelial resistance (r = -0.438 and -0.305, respectively) and are influenced by the bowel preparation solution and biopsy forceps used, being NaCl and jumbo forceps the most compatible methods with the electrophysiological analysis. The great majority of the individuals (76%) did not report major discomfort due to the short procedure time (max 15 min) and considered it relatively painless (79%). Importantly, most (88%) accept repeating it at least for one more time and 53% for more than 4 times.
Obtaining rectal biopsies with a flexible endoscope and jumbo forceps after bowel preparation with NaCl solution is a safe procedure that can be adopted for both adults and children of any age, yielding viable specimens for CFTR bioelectrical/biochemical analyses. The procedure is well tolerated by patients, demonstrating its feasibility as an outcome measure in clinical trials.
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).
This article has been retracted at the ...request of the Editor-in-Chief and Deputy Editor-in-Chief following an investigation into the data that were presented in several figures within the article.
A number of images used in this article are believed to be duplicated images. The authors stated that they inadvertently inserted images of the wrong blots in several of the figures, resulting in the duplications; however, they did not address all of the concerns raised. Because the editors were no longer confident in the conclusions of the article based on these incorrect data, a decision was made to retract the paper.
All authors have been notified of this decision. The University of Campinas (UNICAMP) in São Paulo, Brazil was contacted regarding these concerns, but to date the journal has received no response.
Resumo: Esta proposta baseou-se no modelo estrutural para análise da avaliação formativa, composto por processos inter-relacionados: comunicação de expectativas e critérios de sucesso; obtenção, ...coleta e interpretação de informações; fornecimento de feedback; e regulação da aprendizagem. Para ajudar o professor na implementação da avaliação formativa, articularam-se, com esses processos, as práticas: metodologia de aprendizagem baseada em problemas (ABP) e dimensões culturais de Hofstede. Durante um semestre e meio avaliou-se estatisticamente o desempenho de 55 estudantes. Competências e habilidades foram avaliadas em situações-problemas retiradas do Exame Nacional do Ensino Médio. O perfil cultural foi determinado pelo questionário Value Survey Model 1994. Como resultado observou-se melhora no desempenho acadêmico (p<0,05) e no comportamental dos estudantes (p<0,05). Porém, como a atribuição de nota é exigência do sistema, a postura avaliativa percorreu um nível intermediário entre classificatória e formativa. Formulários de apoio incluídos no plano pedagógico da escola favoreceram a prática de avaliação formativa.
Abstract: This proposal was based on a structural model for analyzing formative assessment that is composed of interrelated processes: communication of expectancies and success criteria, elicitation, collection and interpretation of information, provision of feedback, and regulation of learning. To help the teacher in the implementation of formative assessment, specific practices were articulated with those processes, namely the problem-based learning (PBL) methodology and Hofstede's cultural dimensions. For one semester and a half, the performance of 55 students was statistically evaluated. Competences and abilities were assessed in problem situations taken from Exame Nacional do Ensino Médio, and the cultural profile was determined by the Value Survey Model 1994 questionnaire. As a result, there was an improvement in both students' academic performance (p<0.05) and behavioral performance (p<0.05). However, as rating is a requirement in the system, the evaluation was at an intermediate degree between classificatory and formative. Supportive feedback forms included in the school’s pedagogical plan favored the practice of formative assessment.
Abstract
Sea surface temperature (SST) anomalies caused by a warm core eddy (WCE) in the Southwestern Atlantic Ocean (SWA) rendered a crucial influence on modifying the marine atmospheric boundary ...layer (MABL). During the first cruise to support the Antarctic Modeling and Observation System (ATMOS) project, a WCE that was shed from the Brazil Current was sampled. Apart from traditional meteorological measurements, we used the Eddy Covariance method to directly measure the ocean–atmosphere sensible heat, latent heat, momentum, and carbon dioxide (CO
2
) fluxes. The mechanisms of pressure adjustment and vertical mixing that can make the MABL unstable were both identified. The WCE also acted to increase the surface winds and heat fluxes from the ocean to the atmosphere. Oceanic regions at middle and high latitudes are expected to absorb atmospheric CO
2
, and are thereby considered as sinks, due to their cold waters. Instead, the presence of this WCE in midlatitudes, surrounded by predominantly cold waters, caused the ocean to locally act as a CO
2
source. The contribution to the atmosphere was estimated as 0.3 ± 0.04 mmol m
−2
day
−1
, averaged over the sampling period. The CO
2
transfer velocity coefficient (
K
) was determined using a quadratic fit and showed an adequate representation of ocean–atmosphere fluxes. The ocean–atmosphere CO
2
, momentum, and heat fluxes were each closely correlated with the SST. The increase of SST inside the WCE clearly resulted in larger magnitudes of all of the ocean–atmosphere fluxes studied here. This study adds to our understanding of how oceanic mesoscale structures, such as this WCE, affect the overlying atmosphere.
The oceanic South Atlantic Convergence Zone (SACZ) has played a major role during South America's 2021/2022 summer extreme rainy season, being responsible for more than 90% of the precipitation in ...some regions of Southeast Brazil and in some regions of the Southwestern Atlantic Ocean (SWA). The summer of 2021/2022 was unique and rare and considered an abnormally humid season as verified by official Brazilian Institutes. First, the unusual number of cases of SACZ episodes (seven), was the highest recorded in the last decade. Second, all the cases that occurred were oceanic SACZ that assumed characteristics of an Atmospheric River and produced an excessively anomalous amount of precipitation during this period. Excess precipitation along with the regions located in mountainous and very uneven relief, which by orographic effects favors high precipitation volumes, were responsible for amplifying the observed impacts, such as landslides and floods that caused several losses to society. We also showed the main effects of coupling and interaction between the waters of the surface layer of the SWA and the atmosphere. Our learning from this study ends with the unprecedented results of how the marine atmospheric boundary layer (MABL) is locally modulated by the sea surface temperature (SST) that lies just below it. Until the present moment, we emphasize that this important mechanism has not been widely highlighted in the literature, showing that even though the ocean is colder than before oceanic SACZ is established, it is still warmer than the overlying air, thus, the ocean continues to be an active source of heat and moisture for the atmosphere and enhances the MABL instability process.
Colorectal cancer exerts a strong influence on the epidemiological panorama worldwide, and it is directly correlated to etiologic factors that are substantiated by genetic and environmental elements. ...This complex mixture of factors also has a relationship involving the structural dependence and composition of the gut microbiome, leading to a dysbacteriosis process that may evolve to serious modifications in the intestinal lining, eventually causing the development of a neoplasm. The gastrointestinal tract presents defense strategies and immunological properties that interfere in intestinal permeability, inhibiting the bacterial translocation, thus maintaining the integrity of intestinal homeostasis. The modulation of the intestinal microbiome and the extinction of risk factors associated with intestinal balance losses, especially of environmental factors, make cell and defense alterations impossible. This modulation may be conducted by means of functional foods in the diet, especially soluble fibers, polyunsaturated fatty acids, antioxidants and prebiotics that signal immunomodulatory effects in the intestinal microbiota, with preventive and therapeutic action for colorectal cancer. In summary, this review focuses on the importance of dietary modulation of the intestinal microbiota as an instrument for dysbacteriosis and, consequently, for the prevention of colorectal cancer, suggesting anticarcinogenic, and antiangiogenic properties. Among the intestinal modulating agents considered here are functional foods, especially flaxseed, oat and soy, composing a Bioactive Food Compound.
PDF
