Filtering of false positive microRNA candidates by a clustering-based approach

B M C BioinformaticsBackground: MicroRNAs are small non-coding RNA gene products that play diversified roles from species to species. The explosive growth of microRNA researches in recent years proves the importance of microRNAs in the biological system and it is believed that microRNAs have valuable therapeutic potentials in human diseases. Continual efforts are therefore required to locate and verify the unknown microRNAs in various genomes. As many miRNAs are found to be arranged in clusters, meaning that they are in close proximity with their neighboring miRNAs, we are interested in utilizing the concept of microRNA clustering and applying it in microRNA computational prediction. Results: We first validate the microRNA clustering phenomenon in the human, mouse and rat genomes. There are 45.45%, 51.86% and 48.67% of the total miRNAs that are clustered in the three genomes, respectively. We then conduct sequence and secondary structure similarity analyses among clustered miRNAs, non-clustered miRNAs, neighboring sequences of clustered miRNAs and random sequences, and find that clustered miRNAs are structurally more similar to one another, and the RNAdistance score can be used to assess the structural similarity between two sequences. We therefore design a clustering-based approach which utilizes this observation to filter false positives from a list of candidates generated by a selected microRNA prediction program, and successfully raise the positive predictive value by a considerable amount ranging from 15.23% to 23.19% in the human, mouse and rat genomes, while keeping a reasonably high sensitivity. Conclusion: Our clustering-based approach is able to increase the effectiveness of currently available microRNA prediction program by raising the positive predictive value while maintaining a high sensitivity, and hence can serve as a filtering step. We believe that it is worthwhile to carry out further experiments and tests with our approach using data from other genomes and other prediction software tools. Better results may be achieved with fine-tuning of parameters. © 2008 Leung et al; licensee BioMed Central Ltd.published_or_final_versio

Down-regulation of Sox7 is associated with aberrant activation of Wnt/b-catenin signaling in endometrial cancer

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Using blogs to support information, knowledge sharing, and provide emotional support during internship

This study sought to understand the use of web logs to facilitate information sharing, knowledge sharing, and emotional support for internship students. Fifty-three (53) students from the BScIM Programme (Bachelor of Science in Information Management) evaluated the use of blogs during their internship. The results reveal that students generally have positive perceptions on blogging as a tool to facilitate information management and social support. The blogs are also perceived to be useful in terms of self-reflection, communication, and learning problem-solving skills. On the other hand, this study shows that the supervisor-students communication via blog comments needs to be improved. Finally, the blogging platform does not seem to have an impact on the students’ perceptions of the usefulness and effectiveness of blogs.postprintThe 6th International Conference on Knowledge Management (ICKM 2009), Hong Kong, 3-4 December 2009. In Proceedings of the ICKM, 2009, p. 1-1

Using blogs to support internship for information management and nursing students

postprintThe 6th International Conference on Knowledge Management (ICKM 2009), Hong Kong, 3-4 December 2009. In Proceedings of the ICKM, 2009, p. 1-1

Applying Web 2.0 in medical-related organizations

This study investigated the application of Web 2.0 to medical-related organizations. Thirty organizations participated in an online survey asking their perceived purposes, benefits and difficulties in using Web 2.0. The selected organizations fell into three categories: university medical libraries, hospitals, and non-profit organizations. Fourteen (46.7%) organizations were currently using Web 2.0, ten (33.3%) planned to use it in the future and six (20%) would not consider using it. A phone interview was further conducted with eight organizations (26.7%) about their opinion on Web 2.0. Results showed that most participants found the application of Web 2.0 beneficial to their organizations. Implications of this study for helping medical-related organizations make decisions regarding the use of Web 2.0 technologies in their organizations are discussed.postprintThe 6th International Conference on Knowledge Management (ICKM 2009), Hong Kong, 3-4 December 2009. In Proceedings of ICKM, 2009, p. 1-1

Aberrant activation of ERK/FOXM1 signaling cascade triggers the cell migration/invasion in ovarian cancer cells

Forkhead box M1 (FOXM1) is a proliferation-associated transcription factor essential for cell cycle progression. Numerous studies have documented that FOXM1 has multiple functions in tumorigenesis and its elevated levels are frequently associated with cancer progression. Here, we characterized the role of ERK/FOXM1 signaling in mediating the metastatic potential of ovarian cancer cells. Immunohistochemical (IHC), immunoblotting and semi-quantitative RT-PCR analyses found that both phospho-ERK and FOXM1 were frequently upregulated in ovarian cancers. Intriguingly, the overexpressed phospho-ERK (p<0.001) and FOXM1 (p<0.001) were significantly correlated to high-grade ovarian tumors with aggressive behavior such as metastasized lymph node (5 out of 6). Moreover, the expressions of phospho-ERK and FOXM1 had significantly positive correlation (p<0.001). Functionally, ectopic expression of FOXM1B remarkably enhanced cell migration/invasion, while FOXM1C not only increased cell proliferation but also promoted cell migration/invasion. Conversely, inhibition of FOXM1 expression by either thiostrepton or U0126 could significantly impair FOXM1 mediated oncogenic capacities. However, the down-regulation of FOXM1 by either thiostrepton or U0126 required the presence of p53 in ovarian cancer cells. Collectively, our data suggest that over-expression of FOXM1 might stem from the constitutively active ERK which confers the metastatic capabilities to ovarian cancer cells. The impairment of metastatic potential of cancer cells by FOXM1 inhibitors underscores its therapeutic value in advanced ovarian tumors. © 2011 Lok et al.published_or_final_versio

Hong Kong domestic health spending: financial years 1989/90 to 2005/06

This report presents the latest estimates of Hong Kong domestic health spending between fiscal years 1989/90 and 2005/06, cross-stratified and categorised by financing source, provider, and function on an annual basis. In fiscal year 2005/06, total health expenditure was HK$71 557 million. In real terms, it grew 6.5$71 557 million total health expenditure in 2005/06, HK$68 810 million (96.2$2746 million (3.8%) on capital expenses (ie investment in medical facilities). Services of curative care accounted for the largest share (67.3%) and were made up of ambulatory services (35.7%), in-patient services (27.7%), day patient hospital services (3.4%), and home care (0.6%). The second largest share was spending on medical goods outside the patient care setting (10.8%). In terms of health care providers, hospitals (44.0%) accounted for the largest share of total health expenditure in 2005/06, followed by providers of ambulatory health care (31.4%). We observed a system-wide trend towards service consolidation at institutions (as opposed to free-standing ambulatory clinics, most of which are staffed by solo practitioners). Not taking capital expenses (ie investment in medical facilities) into account, public current expenditure on health amounted to HK$34 849 million (50.6$33 961 million) was mostly incurred at providers of ambulatory health care (55.8%). This reflects the mixed health care economy of Hong Kong, where public hospitals generally account for about 90% of total bed-days and private doctors (including western and Chinese medicine practitioners) provide about 70% of out-patient care. Although both public and private spending were mostly expended on personal health care services and goods (93.0%), the patterns of distribution among functional categories differed. Public expenditure was targeted at in-patient care (53.7%) and substantially less on out-patient care (24.6%), especially low-intensity first-contact care. In comparison, private spending was concentrated on out-patient care (49.9%), followed by medical goods outside the patient care setting (22.0%) and in-patient care (19.0%). Compared to countries of the Organisation for Economic Co-operation and Development, Hong Kong has devoted a relatively low percentage of gross domestic product on health services in the last decade. As a share of total spending, public funding (either general government revenue or social security funds) was also lower than in most comparably developed economies, although commensurate with its public revenue collection base.published_or_final_versio

Targeting GRB7/ERK/FOXM1 Signaling Pathway Impairs Aggressiveness of Ovarian Cancer Cells

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AMPK Activators Suppress Cervical Cancer Cell Growth through Inhibition of DVL3 Mediated Wnt/β-Catenin Signaling Activity

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AMPK Activators Suppress Cervical Cancer Cell Growth through Inhibition of DVL3 Mediated Wnt/β-Catenin Signaling Activity

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