Authors' response

Author's Response to H.M. Heneghan, N. Miller, M.J. Kerin, Systemic microRNAs: novel biomarkers for colorectal and other cancers?, 2010, v. 59 n. 7, p. 1002-1004postprin

Differential expression of microRNAs in plasma of patients with colorectal cancer: A potential marker for colorectal cancer screening

Objective: MicroRNAs (miRNAs) have been shown to offer great potential in the diagnosis of cancer. We investigated whether plasma miRNAs could discriminate between patients with and without colorectal cancer (CRC). Methods: This study was divided into three phases: (1) marker discovery using real-time PCR-based miRNA profiling on plasma, corresponding cancerous and adjacent non-cancerous colonic tissues of five patients with CRC, along with plasma from five healthy individuals as controls; (2) marker selection and validation by real-time quantitative RT-PCR on a small set of plasma; and (3) independent validation on a large set of plasma from 90 patients with CRC, 20 patients with gastric cancer, 20 patients with inflammatory bowel disease (IBD) and 50 healthy controls. Results: Of the panel of 95 miRNAs analysed, five were upregulated both in plasma and tissue samples. All the five miRNAs were validated on the plasma of 25 patients with CRC and 20 healthy controls. Both miR-17-3p and miR-92 were significantly elevated in the patients with CRC (p<0.0005). The plasma levels of these markers were significantly reduced after surgery in 10 patients with CRC (p<0.05). Further validation with an independent set of plasma samples (n=180) indicated that miR-92 differentiates CRC from gastric cancer, IBD and normal subjects. This marker yielded a receiver operating characteristic curve area of 88.5%. At a cut-off of 240 (relative expression in comparison to RNU6B snRNA), the sensitivity was 89% and the specificity was 70% in discriminating CRC from control subjects. Conclusion: MiR-92 is significantly elevated in plasma of patients with CRC and can be a potential non-invasive molecular marker for CRC screening.published_or_final_versio

microRNA-29b prevents liver fibrosis by attenuating hepatic stellate cell activation and inducing apoptosis through targeting PI3K/AKT pathway

microRNA-29b (miR-29b) is known to be associated with TGF-β-mediated fibrosis, but the mechanistic action of miR-29b in liver fibrosis remains unclear and is warranted for investigation. We found that miR-29b was significantly downregulated in human and mice fibrotic liver tissues and in primary activated HSCs. miR-29b downregulation was directly mediated by Smad3 through binding to the promoter of miR-29b in hepatic stellate cell (HSC) line LX1, whilst miR-29b could in turn suppress Smad3 expression. miR-29b transduction in the liver of mice prevented CCl4 induced-fibrogenesis, concomitant with decreased expression of α-SMA, collagen I and TIMP-1. Ectopic expression of miR-29b in activated HSCs (LX-1, HSC-T6) inhibited cell viability and colony formation, and caused cell cycle arrest in G1 phase by downregulating cyclin D1 and p21cip1. Further, miR-29b induced apoptosis in HSCs mediated by caspase-9 and PARP. miR-29b inhibited its downstream effectors of PIK3R1 and AKT3 through direct targeting their 3'UTR regions. Moreover, knockdown of PIK3R1 or AKT3 suppressed α-SMA and collagen I and induced apoptosis in both HSCs and in mice. In conclusion, miR-29b prevents liver fibrogenesis by inhibiting HSC activation and inducing HSC apoptosis through inhibiting PI3K/AKT pathway. These results provide novel mechanistic insights for the anti-fibrotic effect of miR-29b.published_or_final_versio

Different cell kinetic changes in rat stomach cancer after treatment with celecoxib or indomethacin: Implications on chemoprevention

Aim: Mechanisms underlying the chemopreventive effects of cyclooxygenase (COX) inhibitors remain elusive. We have previously shown that celecoxib but not indomethacin could prevent carcinogen-induced gastric cancer development in Wistar rats. This chemopreventive effect appeared to be independent of COX-2 and prostaglandin (PG) E2 suppression since the lowest PGE2 was obtained in indomethacin group. This study compared the cell kinetic changes in stomachs of rats after treatment with celecoxib (5, 10, 20 mg/(kg·d)) or indomethacin (3 mg/(kg·d)) to gain more insights into the chemopreventive mechanism. Methods: The apoptosis and proliferation indexes in gastric tumor, adjacent non-cancer tissues and normal gastric tissues were determined. Apoptosis was quantified by apoptotic nuclei counting and TUNEL, whereas proliferation was determined by Ki67 immunostaining. Results: Treatment with either celecoxib or indomethacin inhibited gastric tumor proliferation by more than 65% (P<0.02). However, celecoxib caused a dose-dependent increase in apoptosis (P<0.05) which was not seen in indomethacin-treated tumors (P = 0.54). The highest apoptosis to proliferation ratio was seen in tumors treated with celecoxib at 10 mg/(kg·d). Treatment with this dose of celecoxib was associated with the lowest incidence of gastric cancer development. Conclusion: Our findings suggest that the difference in chemopreventive effects of indomethacin and celecoxib in this animal model of gastric carcinogenesis is largely due to the differential cell kinetic changes, which does not correlate with the degree of COX-2 and PG suppression. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio

Sexualidade da pessoa com deficiência intelectual - Atitudes de pais e profissionais

Dissertação de Mestrado em Psicologia Educacional, apresentada ao ISPA - Instituto UniversitárioTendo em conta que as atitudes dos pais e profissionais face à sexualidade das pessoas com deficiência intelectual têm um papel preponderante na disponibilização de oportunidades de vivências e experiências sexuais e na passagem de informação correcta acerca da sexualidade (Brown & Pirtle, 2008), o presente estudo pretende conhecer e analisar as atitudes e necessidades que ambos têm, bem como verificar se existem diferenças estatisticamente significativas entre elas. Tendo sido utilizada uma abordagem mista através da utilização do questionário ASQ-ID- Attitudes to Sexuality Questionnaire (Individuals with an Intellectual Disability) e de uma entrevista semi-estruturada, o presente estudo contou com uma amostra de 130 participantes (80 profissionais e 50 pais), dos quais três mães e três profissionais foram entrevistados. Os resultados obtidos confirmaram a nossa hipótese de que existem diferenças estatisticamente significativas nas atitudes dos pais e profissionais, demonstrando que os profissionais têm atitudes mais liberais. Através das entrevistas, verificámos que os profissionais têm necessidades de formação no que toca à capacidade para intervirem de forma adequada nas várias manifestações sexuais dos seus clientes, tendo sido enfatizada a necessidade do envolvimento da família neste processo, a consideração das diferenças individuais e a promoção de contextos favoráveis nas instituições para as vivências e experiências sexuais desta população. Por fim, atestou-se ainda através do discurso dos inquiridos, a falta de um consenso dentro das instituições acerca daquilo que devem fazer em situações onde os clientes necessitam de resposta.ABSTRACT: Given that the attitudes of parents and professionals towards sexuality of people with intellectual disabilities have a role in providing opportunities for experiences and sexual experiences and pass correct information about sexuality (Brown & Pirtle, 2008), this study seeks to examine and analyze the attitudes and needs that both have and see if there are statistically significant differences between them. Having used a mixed approach by using the questionnaire ASQ-ID-Attitudes to Sexuality Questionnaire (Individuals with an Intellectual Disability) and a semi-structured interview, this study involved a sample of 130 participants (80 professionals and 50 parents), of which three mothers and three professionals were interviewed. The results confirmed our hypothesis that there are significant differences in the attitudes of parents and professionals, demonstrating that professionals have more liberal attitudes. Through the interviews, we found that professionals have training needs in relation to the ability to intervene appropriately in various sexual manifestations of its customers, having emphasized the need to involve the family in this process, consideration of individual differences and promoting favorable contexts in institutions for sexual experiences and the experiences of this population. Finally, it is also attested by the discourse of the respondents, the lack of consensus within institutions about what they should do in situations where customers need to be answered

Viral Replication in the Nasopharynx Is Associated with Diarrhea in Patients with Severe Acute Respiratory Syndrome

The role of severe acute respiratory syndrome (SARS) coronavirus as an enteric pathogen was investigated in a cohort of 142 patients with SARS who were treated with a standard treatment protocol. Data from daily hematological, biochemical, radiological, and microbiological investigations were prospectively collected, and the correlation of these findings with diarrhea was retrospectively analyzed. Sixty-nine patients (48.6%) developed diarrhea at a mean (± standard deviation [SD]) of 7.6 ± 2.6 days after the onset of symptoms. The diarrhea was most severe at a mean (± SD) of 8.8 ± 2.4 days after onset, with a maximum frequency of 24 episodes per day (median, 5 episodes; range, 3-24 episodes). A higher mean virus load in nasopharyngeal specimens obtained on day 10 after the onset of symptoms was significantly associated with the occurrence of diarrhea (3.1 log 10 vs. 1.8 log 10 copies/mL; P = .01) and mortality (6.2 vs. 1.7 log 10 copies/mL; P<.01). However, diarrhea was not associated with mortality. The lung and the gastrointestinal tract may react differently to SARS coronavirus infection. Additional investigation of the role of SARS coronavirus in the pathogenesis of diarrhea in patients with SARS should be conducted.published_or_final_versio