A mass spectrometric investigation of novel quadruplex DNA-selective berberine derivatives

ESI mass spectrometry was used to assess the binding of 13-substituted, 5-nitro-2-phenylindolyl- and 2-naphthalenyl-based berberine derivatives to inter- and intramolecular G-quadruplex DNA molecules. In contrast with the parent berberine, the compounds showed selectivity for quadruplex over duplex DNA and stabilised the quadruplex structure. They represent a new class of quadruplex DNA-selective ligands. © 2010 The Royal Society of Chemistry

Synthesis of a mitochondria-targeted spin trap using a novel Parham-type cyclization

A new cyclic nitrone spin trap, [4-(3′,3′-dibutyl-2′-oxy-3′H-isoindol-5′-yloxy)butyl]triphenylphosphonium bromide (MitoSpin), bearing a lipophilic cation has been prepared by a route that involves a novel Parham-type lithiation–cyclization of an isocyanate to give the isoindolinone core. MitoSpin accumulates in a membrane potential dependent way in energized mitochondria and its oxidation could potentially be used in the study of oxidative stress resulting from reactive oxygen species generated in mitochondria

Independent Predictors of Repeat Emergency Room Presentations: Insights from a Cohort of 1066 Consecutive Patients with Non-Cardiac Chest Pain Generating 4770 Repeat Presentations

Background and importanceChest pain (CP) is one of the most frequent presentations to the emergency department (ED), a large proportion of which is non-cardiac chest pain (NCCP). Repeat attendances to ED are common and impose considerable burden to overstretched departments.ObjectiveOur aim was to determine drivers for repeat ED presentations using NCCP as the primary cause of index presentation.Design, setting and participantsThis was a retrospective cohort study of 1066 consecutive presentations with NCCP to a major urban hospital ED in North England. Index of Multiple Deprivation (IMD), a postcode-derived validated index of deprivation, was computed. Charlson comorbidity index (CCI) was determined by reference to known comorbidity variables. Repeat presentation to ED to any national hospital was determined by a national linked database (population 53.5 million). Independent predictors of ED representation were computed using logistic regression analysis.ResultsMedian age was 43 (IQR 28-59), and 50.8% were male. Furthermore, 27.8%, 8.1% and 3.8% suffered from chronic obstructive pulmonary disease (COPD), hypertension and diabetes mellitus, respectively. The most frequent diagnoses, using ICD-10 coding, were non-cardiac chest pain (55.1%), followed by respiratory conditions (14.7%). One-year incidence of adjudicated myocardial infarction, urgent or emergency coronary revascularisation and all-cause death was 0.6%, 2% and 5.3%, respectively. There was a total of 4770 ED repeat presentations 1 year prior to or following index presentation with NCCP in this cohort. Independent (multivariate) predictors for frequent re-presentation (defined as ≥2 representations) were a history of COPD (OR [odds ratio] 2.06, p = 0.001), previous MI (OR3.6, p = 0.020) and a Charlson comorbidity index ≥1 (OR 1.51, p = 0.030). The frequency of previous MI was low as only 3% had sustained a previous MI.ConclusionsThis analysis indicates that COPD and complex health care needs (represented by high CCI), but not socio-economic deprivation, should be health policy targets for lessening repeat ED presentations. What is already known on this topic: Repeat presentations with non-ischaemic chest pain are common, placing a considerable burden on emergency departments.What this study addsCOPD and complex health care needs, denoted by Charlson comorbidity index, are implicated as drivers for repeat presentation to accident and emergency department. Socio-economic deprivation was not an independent predictor of re-presentation. How might this study affect research, practice, or policy: Community-based support for COPD and complex health care needs may reduce frequency of ED attendance

Unravelling links between squid catch variations and biophysical mechanisms in South African waters

Using satellite observations, this study uncovers the biophysical drivers of the lucrative chokka squid fishery in South Africa over the last two decades (1998–2017) and addresses their potential links with low squid catches. Chokka squid fishing is crucial to the economic wellbeing of local communities. However, the squid biomass is prone to considerable fluctuations, including abrupt declines with negative socio-economic impacts. We show that the squid catch is significantly and positively correlated with satellite-derived chlorophyll-a (Chl-a, an index of phytoplankton biomass) from year to year in South African coastal waters. Two main phytoplankton blooms are observed to occur seasonally in the austral spring and autumn, peaking in October and April, respectively. From October to April, phytoplankton abundance is influenced by the occurrence of wind-driven upwelling over the South African west coast (southern Benguela) and the central Agulhas Bank (so-called Cold Ridge upwelling), while the surface currents appear more important for shelf edge processes and advection along the Cold Ridge on shorter timescales. Low squid catches are observed in 2001 and 2013 and linked to declines in Chl-a induced by weak winds and relaxed negative wind stress curl over the southwest coast in 2001, and over the southwest coast and the central Agulhas Bank in 2013. Phytoplankton phenology (bloom timing) analysis reveals absent, or shorter and delayed blooms, over the Benguela upwelling region in 2001 and both the Benguela and Cold Ridge upwelling areas in 2013. In contrast, the high catch years of 2004 and 2009, associated with elevated Chl-a, coincide with early and/or prolonged seasonal blooms. These are induced by strong winds over the Benguela upwelling and Cold Ridge areas in 2004, and by intensified negative wind stress curl over the Benguela upwelling area in 2009. These results show that the squid catch fluctuations are potentially predictable and could support policymakers seeking to improve their planning of adaptation strategies and risk mitigation

British Gynaecological Cancer Society Recommendations for Evidence Based, Population Data Derived Quality Performance Indicators for Ovarian Cancer

Ovarian cancer survival in the UK lags behind comparable countries. Results from the ongoing National Ovarian Cancer Audit feasibility pilot (OCAFP) show that approximately 1 in 4 women with advanced ovarian cancer (Stage 2, 3, 4 and unstaged cancer) do not receive any anticancer treatment and only 51% in England receive international standard of care treatment, i.e., the combination of surgery and chemotherapy. The audit has also demonstrated wide variation in the percentage of women receiving anticancer treatment for advanced ovarian cancer, be it surgery or chemotherapy across the 19 geographical regions for organisation of cancer delivery (Cancer Alliances). Receipt of treatment also correlates with survival: 5 year Cancer survival varies from 28.6% to 49.6% across England. Here, we take a systems wide approach encompassing both diagnostic pathways and cancer treatment, derived from the whole cohort of women with ovarian cancer to set out recommendations and quality performance indicators (QPI). A multidisciplinary panel established by the British Gynaecological Cancer Society carefully identified QPI against criteria: metrics selected were those easily evaluable nationally using routinely available data and where there was a clear evidence base to support interventions. These QPI will be valuable to other taxpayer funded systems with national data collection mechanisms and are to our knowledge the only population level data derived standards in ovarian cancer. We also identify interventions for Best practice and Research recommendations

Administrative Managers – A Critical Link

Institutional responses to changes in the higher education environment have caused movements in the roles and identities of administrative managers in UK universities. These shifts have highlighted the problem for individuals of balancing traditional public service considerations of administration with institutional innovation and development. Administrative managers find themselves not only acting as independent arbiters, giving impartial advice on the basis of professional expertise, but also becoming involved in political judgements about institutional futures. They increasingly undertake an interpretive function between the various communities of the university and its external partners. As the boundaries of the university have become more permeable, administrative and academic management have inter-digitated, and hybrid roles have developed. In undertaking increasingly complex functions, therefore, administrative managers play a critical role in linking the academic and executive arms of governance in the university

The bacterial cell envelope as delimiter of anti-infective bioavailability - An in vitro permeation model of the Gram-negative bacterial inner membrane.

Gram-negative bacteria possess a unique and complex cell envelope, composed of an inner and outer membrane separated by an intermediate cell wall-containing periplasm. This tripartite structure acts intrinsically as a significant biological barrier, often limiting the permeation of anti-infectives, and so preventing such drugs from reaching their target. Furthermore, identification of the specific permeation-limiting envelope component proves difficult in the case of many anti-infectives, due to the challenges associated with isolation of individual cell envelope structures in bacterial culture. The development of an in vitro permeation model of the Gram-negative inner membrane, prepared by repeated coating of physiologically-relevant phospholipids on Transwell(®) filter inserts, is therefore reported, as a first step in the development of an overall cell envelope model. Characterization and permeability investigations of model compounds as well as anti-infectives confirmed the suitability of the model for quantitative and kinetically-resolved permeability assessment, and additionally confirmed the importance of employing bacteria-specific base materials for more accurate mimicking of the inner membrane lipid composition - both advantages compared to the majority of existing in vitro approaches. Additional incorporation of further elements of the Gram-negative bacterial cell envelope could ultimately facilitate model application as a screening tool in anti-infective drug discovery or formulation development

Antioxidant properties of MitoTEMPOL and its hydroxylamine

Piperidine nitroxides such as TEMPOL have been widely used as antioxidants in vitro and in vivo. MitoTEMPOL is a mitochondria-targeted derivative of TEMPOL designed to protect mitochondria from the oxidative damage that they accumulate, but once there is rapidly reduced to its hydroxylamine, MitoTEMPOL-H. As little is known about the antioxidant efficacy of hydroxylamines, this study has assessed the antioxidant activity of both MitoTEMPOL and MitoTEMPOL-H. The hydroxylamine was more effective at preventing lipid-peroxidation than MitoTEMPOL and decreased oxidative damage to mitochondrial DNA caused by menadione. In contrast to MitoTEMPOL, MitoTEMPOL-H has no superoxide dismutase activity and its antioxidant actions are likely to be mediated by hydrogen atom donation. Therefore, even though MitoTEMPOL is rapidly reduced to MitoTEMPOL-H in cells, it remains an effective antioxidant. Furthermore, as TEMPOL is also reduced to a hydroxylamine in vivo, many of its antioxidant effects may also be mediated by its hydroxylamine

Identification of S-nitrosated mitochondrial proteins by S-nitrosothiol difference in gel electrophoresis (SNO-DIGE): implications for the regulation of mitochondrial function by reversible S-nitrosation

The S-nitrosation of mitochondrial proteins as a consequence of NO metabolism is of physiological and pathological significance. We previously developed a MitoSNO (mitochondria-targeted S-nitrosothiol) that selectively S-nitrosates mitochondrial proteins. To identify these S-nitrosated proteins, here we have developed a selective proteomic methodology, SNO-DIGE (S-nitrosothiol difference in gel electrophoresis). Protein thiols in control and MitoSNO-treated samples were blocked, then incubated with copper(II) and ascorbate to selectively reduce S-nitrosothiols. The samples were then treated with thiol-reactive Cy3 (indocarbocyanine) or Cy5 (indodicarbocyanine) fluorescent tags, mixed together and individual protein spots were resolved by 2D (two-dimensional) gel electrophoresis. Fluorescent scanning of these gels revealed S-nitrosated proteins by an increase in Cy5 red fluorescence, allowing for their identification by MS. Parallel analysis by Redox-DIGE enabled us to distinguish S-nitrosated thiol proteins from those which became oxidized due to NO metabolism. We identified 13 S-nitrosated mitochondrial proteins, and a further four that were oxidized, probably due to evanescent S-nitrosation relaxing to a reversible thiol modification. We investigated the consequences of S-nitrosation for three of the enzymes identified using SNO-DIGE (aconitase, mitochondrial aldehyde dehydrogenase and α-ketoglutarate dehydrogenase) and found that their activity was selectively and reversibly inhibited by S-nitrosation. We conclude that the reversible regulation of enzyme activity by S-nitrosation modifies enzymes central to mitochondrial metabolism, whereas identification and functional characterization of these novel targets provides mechanistic insight into the potential physiological and pathological roles played by this modification. More generally, the development of SNO-DIGE facilitates robust investigation of protein S-nitrosation across the proteome