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Exacerbations of chronic obstructive pulmonary disease (COPD) are defined as sustained worsening of a patient's condition beyond normal day-to-day variations that is acute in onset, and that may also require a change in medication and/or hospitalization. Exacerbations have a significant and prolonged impact on health status and outcomes, and negative effects on pulmonary function. A significant proportion of exacerbations are unreported and therefore left untreated, leading to a poorer prognosis than those treated. COPD exacerbations are heterogeneous, and various phenotypes have been proposed which differ in biologic basis, prognosis, and response to therapy. Identification of biomarkers could enable phenotype-driven approaches for the management and prevention of exacerbations. For example, several biomarkers of inflammation can help to identify exacerbations most likely to respond to oral corticosteroids and antibiotics, and patients with a frequent exacerbator phenotype, for whom preventative treatment is appropriate. Reducing the frequency of exacerbations would have a beneficial impact on patient outcomes and prognosis. Preventative strategies include modification of risk factors, treatment of comorbid conditions, the use of bronchodilator therapy with long-acting β2-agonists or long-acting muscarinic antagonists, and inhaled corticosteroids. A better understanding of the mechanisms underlying COPD exacerbations will help to optimize use of the currently available and new interventions for preventing and treating exacerbations.

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease characterized by nonreversible airway obstruction. Well-characterized symptoms such as exertional dyspnea and fatigue have a negative impact on patients' quality of life (QoL) and restrict physical activity in daily life. The impact of COPD symptoms on QoL is often underestimated; for example, 36% of patients who describe their symptoms as being mild-to-moderate also admit to being too breathless to leave the house. Additionally, early morning and nighttime symptoms are a particular problem. Methods are available to allow clinicians to accurately assess COPD symptoms, including patient questionnaires. Integrated approaches to COPD management, particularly pulmonary rehabilitation, are effective strategies for addressing symptoms, improving exercise capacity and, potentially, also increasing physical activity. Inhaled bronchodilators continue to be the mainstay of drug therapy in COPD, where options can be tailored to meet patients' needs with careful selection of the inhaled medication and the device used for its delivery. Overall, an integrated approach to disease management should be considered for improving QoL and subsequent patient outcomes in COPD.

XRCC1 is a scaffold protein that interacts with several DNA repair proteins and plays a critical role in DNA base excision repair (BER). XRCC1 protein is in a tight complex with DNA ligase IIIalpha (Lig III) and this complex is involved in the ligation step of both BER and repair of DNA single strand breaks. The majority of XRCC1 has previously been demonstrated to exist in a phosphorylated form and cells containing mutant XRCC1, that is unable to be phosphorylated, display a reduced rate of single strand break repair. Here, in an unbiased assay, we demonstrate that the cytoplasmic form of the casein kinase 2 (CK2) protein is the major protein kinase activity involved in phosphorylation of XRCC1 in human cell extracts and that XRCC1 phosphorylation is required for XRCC1-Lig III complex stability. We demonstrate that XRCC1-Lig III complex containing mutant XRCC1, in which CK2 phosphorylation sites have been mutated, is unstable. We also find that a knockdown of CK2 by siRNA results in both reduced XRCC1 phosphorylation and stability, which also leads to a reduced amount of Lig III and accumulation of DNA strand breaks. We therefore propose that CK2 plays an important role in DNA repair by contributing to the stability of XRCC1-Lig III complex.

The increasing usage in recent years of trendy, but often ill-defined, terms such as 'lifelong learning' (see Edwards, Raggatt, Harrison, McCollum and Calder, 1998), 'the learning society' (for example, National Grid for Learning, http://www.dfee.gov.uk/grid/challenge/ govermhtm), or 'learning country' (for example, Welsh Office, 1998; ETAG, 1999) indicates the importance that both the public and private sectors attach to the establishment of a learning culture. This has included the recognition that, in order to achieve such a culture, access to learning must be made easier and existing barriers removed. Edwards and his coauthors (1998) maintain that most experts see lifelong learning as a rallying cry, rather than a specific policy. This statement holds true for many similar slogans, but what they have in common is 'the power to unite various stakeholders around the need for change, because it has emerged as a response to today's challenges' (Edwards et al, 1998).

CK2 phosphorylates the scaffold protein XRCC1, which is required for efficient DNA single-strand break (SSB) repair. Here, we express an XRCC1 protein (XRCC1ckm) that cannot be phosphorylated by CK2 in XRCC1 mutated EM9 cells and show that the role of this post-translational modification gives distinct phenotypes in SSB repair and base excision repair (BER). Interestingly, we find that fewer SSBs are formed during BER after treatment with the alkylating agent dimethyl sulfate (DMS) in EM9 cells expressing XRCC1ckm (CKM cells) or following inhibition with the CK2 inhibitor 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT). We also show that XRCC1ckm protein has a higher affinity for DNA than wild type XRCC1 protein and resides in an immobile fraction on DNA, in particular after damage. We propose a model whereby the increased affinity for DNA sequesters XRCC1ckm and the repair enzymes associated with it, at the repair site, which retards kinetics of BER. In conclusion, our results indicate that phosphorylation of XRCC1 by CK2 facilitates the BER incision step, likely by promoting dissociation from DNA.

A significant proportion of human cancers overexpress DNA polymerase beta (Pol beta), the major DNA polymerase involved in base excision repair. The underlying mechanism and biological consequences of overexpression of this protein are unknown. We examined whether Pol beta, expressed at levels found in tumor cells, is involved in the repair of DNA damage induced by oxaliplatin treatment and whether the expression status of this protein alters the sensitivity of cells to oxaliplatin. DNA damage induced by oxaliplatin treatment of HCT116 and HT29 colon cancer cells was observed to be associated with the stabilization of Pol beta protein on chromatin. In comparison with HCT116 colon cancer cells, isogenic oxaliplatin-resistant (HCT-OR) cells were found to have higher constitutive levels of Pol beta protein, faster in vitro repair of a DNA substrate containing a single nucleotide gap and faster repair of 1,2-GG oxaliplatin adduct levels in cells. In HCT-OR cells, small interfering RNA knockdown of Pol beta delayed the repair of oxaliplatin-induced DNA damage. In a different model system, Pol beta-deficient fibroblasts were less able to repair 1,2-GG oxaliplatin adducts and were hypersensitive to oxaliplatin treatment compared with isogenic Pol beta-expressing cells. Consistent with previous studies, Pol beta-deficient mouse fibroblasts were not hypersensitive to cisplatin treatment. These data provide the first link between oxaliplatin sensitivity and DNA repair involving Pol beta. They demonstrate that Pol beta modulates the sensitivity of cells to oxaliplatin treatment.

Base excision repair (BER) is the major cellular pathway involved in removal of endogenous/spontaneous DNA lesions. Here, we study the mechanism that controls the steady-state levels of BER enzymes in human cells. By fractionating human cell extract, we purified the E3 ubiquitin ligase Mule (ARF-BP1/HectH9) as an enzyme that can ubiquitylate DNA polymerase beta (Pol beta), the major BER DNA polymerase. We identified lysines 41, 61 and 81 as the major sites of modification and show that replacement of these lysines to arginines leads to increased protein stability. We further show that the cellular levels of Pol beta and its ubiquitylated derivative are modulated by Mule and ARF and siRNA knockdown of Mule leads to accumulation of Pol beta and increased DNA repair. Our findings provide a novel mechanism regulating steady-state levels of BER proteins.

Much of the information stored on the web contains geographical context, but current search engines treat such context in the same way as all other content. In this paper we describe the design, implementation and evaluation of a spatially aware search engine which is capable of handling queries in the form of the triplet of ⟨theme⟩⟨spatial relationship⟩⟨location⟩. The process of identifying geographic references in documents and assigning appropriate footprints to documents, to be stored together with document terms in an appropriate indexing structure allowing real‐time search, is described. Methods allowing users to query and explore results which have been relevance‐ranked in terms of both thematic and spatial relevance have been implanted and a usability study indicates that users are happy with the range of spatial relationships available and intuitively understand how to use such a search engine. Normalised precision for 38 queries, containing four types of spatial relationships, is significantly higher (p

We establish inversion formulas of the so called filtered back-projection type to recover a function supported in the ball in even dimensions from its spherical means over spheres centered on the boundary of the ball. We also find several formulas to recover initial data of the form (f,0) (or (0,g)) for the free space wave equation in even dimensions from the trace of the solution on the boundary of the ball, provided the initial data has support in the ball., 26 pages, 5 figures