Search

418 British Journal of Healthcare Management 2014 Vol 20 No 9 © 2 01 4 M A H ea lth ca re L td infections and surgical site infections are the most common HCAIs, other more serious infections occur. These can include dangerous bloodstream infections associated with the frequent use of intravascular access devices. These infections frequently worsen the patient’s underlying condition, prolong recovery, delay hospital discharge, postpone new admissions and may cause serious disability and death. In addition, these infections significantly increase the cost of care. Almost 15 years ago, the estimated costs to NHS hospitals in England for people that acquired HCAIs was over £1 billion a year, the equivalent to the annual running costs of more than eight NHS hospitals (Plowman et al, 1999). Surely this cost to the NHS will have greatly escalated since then. As people become more aware of the risk of infection, they often become frightened and lose confidence in the NHS to protect them from acquiring new infections during periods of hospitalisation. As society become ever more litigiousness, patients are increasingly likely to seek compensation if harmed by any avoidable risk, including HCAIs. During recent years, a series of highly focused and integrated strategies have been initiated in the UK to better protect patients from the risk of acquiring HCAIs. Although extraordinarily successful in reducing the rates of infection caused by some specifically targeted microbial threats, such as meticillinresistant Staphylococcus aureus and Clostridium difficile (National Audit Office 2012), newer types of pathogenic drug-resistant microorganisms, such as enterobacteriaceae, have emerged that are equally—if not more— dangerous and often difficult or impossible to treat with drug-sensitive antimicrobial agents. Many, if not most of these infections, are preventable and essential tools to do this include: Robert J Pratt CBE, Emeritus Professor of Nursing, University of West London epic3: An evidence-based approach for protecting patients and saving lives

The presence of unpaired copies of a gene during meiosis triggers silencing of all copies of the gene in the diploid ascus cell of Neurospora. This phenomenon is called meiotic silencing and on the basis of genetic studies appears to be a post-transcriptional gene silencing (PTGS) mechanism. Previously, meiotic silencing was defined to be induced by the presence of a DNA region lacking an identical segment in the homologous chromosome. However, the determinants of unpaired DNA remained a mystery. Using the Ascospore maturation-1 (Asm-1) gene, we defined what needs to be “unpaired” to silence a gene. For efficient silencing, an unpaired region of DNA needs to be of a sufficient size and contain homology to the reporter transcript. The greater the size of the loop and the larger the homology to the reporter transcript, the better the resulting meiotic silencing is. Conversely, regions not containing homology to the transcript, e.g., intergenic regions, did not silence the reporter. Surprisingly, unpaired fragments lacking a canonical promoter silenced the reporter. Additionally, we detected the unpairing-dependent loss of a transcript during meiotic silencing. Our observations further support a PTGS mechanism for meiotic silencing and offer insight into the evolutionary consequences resulting from this novel meiotic checkpoint.

Neurospora crassa is a central organism in the history of twentieth-century genetics, biochemistry and molecular biology. Here, we report a high-quality draft sequence of the N. crassa genome. The approximately 40-megabase genome encodes about 10,000 protein-coding genes—more than twice as many as in the fission yeast Schizosaccharomyces pombe and only about 25% fewer than in the fruitfly Drosophila melanogaster. Analysis of the gene set yields insights into unexpected aspects of Neurospora biology including the identification of genes potentially associated with red light photobiology, genes implicated in secondary metabolism, and important differences in Ca21 signalling as compared with plants and animals. Neurospora possesses the widest array of genome defence mechanisms known for any eukaryotic organism, including a process unique to fungi called repeat-induced point mutation (RIP). Genome analysis suggests that RIP has had a profound impact on genome evolution, greatly slowing the creation of new genes through genomic duplication and resulting in a genome with an unusually low proportion of closely related genes.

Before any genetic exchange can take place between the chromosomes participating in meiosis, the molecules must first physically pair. The process of meiotic long-distance pairing must involve trans-sensing between chromosomal segments, but the relationship between these kinds of sensing and that of the trans-sensing that activates meiotic silencing is unknown. This chapter considers the trans-sensing that is involved in the early evaluation of every chromosomal DNA segment and the one involved in meiotic silencing as being the same. The trans-sensing between the genomes participating in meiosis occurs concomitantly with the coalignment of homologous chromosomes and requires extensive searching and satisfaction of stringent molecular homology criteria before recombination is allowed. Understanding meiotic silencing in Neurospora requires knowledge about the life cycle of N. crassa. The pairs of homologous chromosomes of N. crassa will first undergo premeiotic DNA replication, generating sister chromatids attached along their length by cohesin. The participating parental nuclei will then fuse at karyogamy, generating a diploid nucleus. In Neurospora, testing the involvement of genes in meiotic silencing is not straightforward. The diploid nature of the meiotic cell makes it difficult to identify recessive alleles in genes involved in the process. The ancient origins of meiotic silencing in all of its current manifestations are likely grounded in RNAi-mediated genome defense mechanisms. The study of meiotic trans-sensing and meiotic silencing is important not only from a mechanistic perspective but also from an evolutionary point of view.

This second in a two-part unit on swine flu looks at infection control measures for nurses. During late spring and early summer, increasing numbers of people became infected with novel swine origin influenza type A virus (influenza A(H1N1)v 2009) and a global pandemic started. Part 1 of this unit explored the biology of influenza viruses and the origins and characteristics of flu pandemics. This part reviews viral transmission, infection prevention and control and pandemic preparedness.

This first in a two-part unit on pandemic flu examines background information on influenza viruses and previous pandemics. As the 2009 flu pandemic gathers force, nurses and other healthcare professionals need to understand the scientific background to one of the most common and potentially the most lethal of pandemic infections. This part explores the characteristics of influenzaviruses and reviews the history and context in which human pandemics occur.

This is a two-part unit on HIV infection and Aids. Part 1 reviewed the evolving global and national epidemiology of HIV infection and Aids. This second part examines routes of transmission, diagnosis and antiretroviral treatment.

This is the first of a two-part unit on HIV and Aids. This part reviews the global epidemiology of the HIV/Aids pandemic.

During the early stages of meiosis in Neurospora, the symmetry of homologous chromosomal regions is carefully evaluated by actively trans-sensing their identity. If a DNA region cannot be detected on the opposite homologous chromosome, then this lack of “sensing” activates meiotic silencing, a post-transcriptional gene silencing-like mechanism that silences all genes in the genome with homology to the loop of unpaired DNA, whether they are paired or unpaired. In this work, we genetically dissected the meiotic trans-sensing step from meiotic silencing by demonstrating that DNA methylation affects sensing without interfering with silencing. We also determined that DNA sequence is an important parameter considered during meiotic trans-sensing. Altogether, these observations assign a previously undescribed role for DNA methylation in meiosis and, on the basis of studies in other systems, we speculate the existence of an intimate connection among meiotic trans-sensing, meiotic silencing, and meiotic recombination.

We demonstrate the involvement of suppressor of meiotic silencing-2 (sms-2+), a Neurospora gene coding for an Argonaute-like protein, in meiotic silencing and normal sexual development.

This Strategic Research Project seeks to determine whether a potential adversary's introduction of an invasive species (Ebola, brown tree snake, zebra mussel etc.) into the United States poses a threat to our national security. This Strategic Research Project analyzes historical precedents to determine their effects and thus to predict the effects of a future attack. Several examples are used to depict this, to include a foot and mouth disease attack to destroy the livestock industry. The project examines reasons an adversary may choose this type of attack. It then assesses the Invasive Species Management Plan of the National Invasive Species Council. It concludes with recommendations for strengthening the nation's defense against an invasive species attack.

This paper is the second in a two-part series summarising the main findings and conclusions of a review of the roles and responsibilities of infection prevention and control nurses commissioned by the Department of Health. It describes the core work of IPCNs, discusses the strengths and constraints of the current role and makes suggestions for future development.

Here, we report the use of the mating type heterokaryon incompatibility system as a counterselection to increase the probability of identifying gene replacements in Neurospora crassa. We compared the frequencies of gene replacements observed among transformants obtained by using plasmids with or without the mat a-1+ gene (hereby called “Toxic Gene”) placed adjacent to disruption cassettes. On an average, we were 20× more likely to identify a correct gene replacement by incorporating the toxic gene in our constructs. Using this strategy, we constructed strains containing a deletion of the inl (1 l -myo-inositol-1-phosphate synthase) gene. Finally, we demonstrated that we were able to remove the transformation marker (the hygromycin B phosphotransferase- thymidine kinase gene fusion [hph+::tk+]) from the genome by using a strategy similar to the “URA-blaster” strategy used in yeast, which we call “tk-blaster.”

RNA has emerged as an important regulatory substance. Studies with worms, plants, and the filamentous fungus Neurospora crassa have demonstrated that double-stranded RNA (dsRNA) can cause degradation of matching mRNA, resulting in RNA interference (RNAi) ([ 1 ][1]). In fission yeast [reviewed in ([

In 1983, the aetiological agent of AIDS was discovered by French scientists and was termed the 'lym- phadenopathy-associated virus' (LAV) [ 1 ]. A year later, American researchers also described this retrovirus and termed it the 'Human T-cell leukemia virus, type III' (HTLV-III) [ 2 ], Both LAV and HTLV-III were the same retrovirus and in 1986, it was agreed that the viruses which can cause AIDS be termed the 'human immunodeficiency viruses' (HIV).