Germinal Centre B Cell Functions and Lymphomagenesis: Circuits Involving MYC and MicroRNAs.

BACKGROUND: The transcription factor MYC regulates several biological cellular processes, and its target gene network comprises approximately 15% of all human genes, including microRNAs (miRNAs), that also contribute to MYC regulatory activity. Although miRNAs are emerging as key regulators of immune functions, the specific roles of miRNAs in the regulation/dysregulation of germinal centre B-cells and B-cell lymphomas are still being uncovered. The regulatory network that integrates MYC, target genes and miRNAs is a field of intense study, highlighting potential pathways to be explored in the context of future clinical approaches. METHODS: The scientific literature that is indexed in PUBMED was consulted for publications involving MYC and miRNAs with validated bioinformatics analyses or experimental protocols. Additionally, seminal studies on germinal centre B-cell functions and lymphomagenesis were reported. CONCLUSIONS: This review summarizes the interactions between MYC and miRNAs through regulatory loops and circuits involving target genes in germinal centre B-cell lymphomas with MYC alterations. Moreover, we provide an overview of the understanding of the regulatory networks between MYC and miRNAs, highlighting the potential implication of this approach for the comprehension of germinal centre B-cell lymphoma pathogenesis. Therefore, circuits involving MYC, target genes and miRNAs provide novel insight into lymphomagenesis that could be useful for new improved therapeutic strategies.

New technologies to monitor healthcare worker hand hygiene.

Compliance with hand hygiene is a good quality indicator for hospital patient safety programmes. Hand hygiene is a major infection control prevention intervention, but in many medical centres compliance rates are only c. 50%. Given the enormous number of hand hygiene opportunities in hospitals, direct observation to monitor compliance is very inefficient. However, technologies are emerging to obviate the need for direct observation. These new technologies for monitoring hand hygiene compliance are discussed in this article.

In silico analysis of the endogenous time-keeping mechanism in citrus

The endogenous time-keeping mechanism is responsible for organizing plant physiology and metabolism according to periodic environmental changes, such as diurnal cycles of light and dark and seasonal progression throughout the year. In plants, circadian rhythms control gene expression, stomatal opening, and the timing component of the photoperiodic responses, leading to enhanced fitness due to increased photosynthetic rates and biomass production. We have investigated the citrus genome databases of expressed sequence tags (EST) in order to identify genes coding for functionally characterized proteins involved in the endogenous time-keeping mechanism in Arabidopsis thaliana. Approximately 180,000 EST sequences from 53 libraries were investigated and 81 orthologs of clock components were identified. We found that the vast majority of Arabidopsis circadian clock genes are present in citrus species, although some important components are absent such as SRR1 and PRR5. Based on the identified transcripts, a model for the endogenous oscillatory mechanism of citrus is proposed. These results demonstrate the power of comparative genomics between model systems and economically important crop species to elucidate several aspects of plant physiology and metabolism.