2-aminophenols containing electron-withdrawing groups from N-aryl hydroxylamines

Reaction of substituted N-aryl hydroxylamines with methanesulfonyl chloride, p-toluenesulfonyl chloride, or trifluoromethanesulfonic anhydride under basic conditions leads to the rearranged 2-aminophenols (45-94%). The overall reaction sequence can be performed using polymer-supported sulfonyl chloride resin allowing for the effective conversion of N-aryl hydroxylamines to the 2-aminophenols without the need for chromatography

Exploring the risks, harms and pleasures of licit and illicit substance use:a study of young people in a South-Yorkshire town

This study explores the localised substance use perceptions, practices and experiences of a sample of socioeconomically disadvantaged young people in a South-Yorkshire town in England. The study investigates how young people assess and understand the risks, harms and pleasures of substance use, and how these understandings, as well as the broader dilemmas of contemporary life, shape substance use. The study examines the contexts, meanings, motivations and consequences of tobacco, alcohol, illegal drug and novel psychoactive substance use, capturing both established and emergent practices across the participants’ leisure spaces. Data was obtained through interviews, participant observations (in street-based leisure spaces), and a targeted survey across an underexplored and ‘hard-to-reach’ cohort of young people aged between 16 and 24. The participants’ perceptions of risk, harm and pleasure were fluid and shaped by experience and exposure to substances, social and cultural norms, and access to trusted and valued knowledge sources. Risk was evaluated through a conceptualisation of the potential for experiencing harm. However, the participants were found to focus on immediate, acute, tangible, visible and social harms in their risk assessments, rather than potential chronic and long-term health harms. The substances and practices which were not perceived to be associated with such immediate issues were differentiated as less risky, irrespective of their potential for long-term harm. The participants appeared to hold potentially erroneous beliefs around their abilities to control and manage substance use, and to avoid negative and long-term harms. Such beliefs shaped substance use practices, the implementation and adherence to harm reduction strategies, and perceptions around how current and future substance use would be managed. The participants’ socioeconomic disadvantage, ‘troubled’ transitional routes and social situations resulted in many being financially, culturally and geographically excluded from ‘adult’ activities and spaces, with this shaping their leisure and substance use practices. The study highlights the enduring relationships between socioeconomic disadvantage, health inequality, and young people’s substance use. Importantly, the findings undermine and unsettle dominant discourses which characterise disadvantaged and disengaged youth as ‘reckless’ and ‘uninformed’ substance users, as well as ‘feckless’ and ‘workless’ individuals

Computational analysis of binding between malarial dihydrofolate reductases and anti-folates

BACKGROUND: Plasmodium falciparum readily develops resistance to the anti-folates pyrimethamine and proguanil via a characteristic set of mutations in the dihydrofolate reductase (PfDHFR) gene that leads to reduced competitive drug binding at the enzyme's active site. Analogous mutations can be found in the DHFR gene in isolates of Plasmodium vivax (PvDHFR) although anti-folates have not been widely used for the treatment of this infection. Here the interactions between DHFR inhibitors and modelled structures of the DHFR enzymes of Plasmodium malariae (PmDHFR) and Plasmodium ovale (PoDHFR) are described, along with an investigation of the effect of recently reported mutations within PmDHFR. METHODS: DHFR models for PmDHFR and PoDHFR were constructed using the solved PfDHFR-TS and PvDHFR structures respectively as templates. The modelled structures were docked with three DHFR inhibitors as ligands and more detailed interactions were explored via simulation of molecular dynamics. RESULTS: Highly accurate models were obtained containing sets of residues that mediate ligand binding which are highly comparable to those mediating binding in known crystal structures. Within this set, there were differences in the relative contribution of individual residues to inhibitor binding. Modelling of PmDHFR mutant sequences revealed that PmDHFR I170M was associated with a significant reduction in binding energy to all DHFR inhibitors studied, while the other predicted resistance mutations had lesser or no effects on ligand binding. CONCLUSIONS: Binding of DHFR inhibitors to the active sites of all four Plasmodium enzymes is broadly similar, being determined by an analogous set of seven residues. PmDHFR mutations found in field isolates influenced inhibitor interactions to a varying extent. In the case of the isolated I170M mutation, the loss of interaction with pyrimethamine suggests that DHFR-inhibitor interactions in P. malariae are different to those seen for DHFRs from P. falciparum and P. vivax

Protein-based signatures of functional evolution in Plasmodium falciparum

Abstract. Background: It has been known for over a decade that Plasmodium falciparum proteins are enriched in non-globular domains of unknown function. The potential for these regions of protein sequence to undergo high levels of genetic drift provides a fundamental challenge to attempts to identify the molecular basis of adaptive change in malaria parasites. Results: Evolutionary comparisons were undertaken using a set of forty P. falciparum metabolic enzyme genes, both within the hominid malaria clade (P. reichenowi) and across the genus (P. chabaudi). All genes contained coding elements highly conserved across the genus, but there were also a large number of regions of weakly or non-aligning coding sequence. These displayed remarkable levels of non-synonymous fixed differences within the hominid malaria clade indicating near complete release from purifying selection (dN/dS ratio at residues non-aligning across genus: 0.64, dN/dS ratio at residues identical across genus: 0.03). Regions of low conservation also possessed high levels of hydrophilicity, a marker of non-globularity. The propensity for such regions to act as potent sources of non-synonymous genetic drift within extant P. falciparum isolates was confirmed at chromosomal regions containing genes known to mediate drug resistance in field isolates, where 150 of 153 amino acid variants were located in poorly conserved regions. In contrast, all 22 amino acid variants associated with drug resistance were restricted to highly conserved regions. Additional mutations associated with laboratory-selected drug resistance, such as those in PfATPase4 selected by spiroindolone, were similarly restricted while mutations in another calcium ATPase (PfSERCA, a gene proposed to mediate artemisinin resistance) that reach significant frequencies in field isolates were located exclusively in poorly conserved regions consistent with genetic drift. Conclusion: Coding sequences of malaria parasites contain prospectively definable domains subject to neutral or nearly neutral evolution on a scale that appears unrivalled in biology. This distinct evolutionary landscape has potential to confound analytical methods developed for other genera. Against this tide of genetic drift, polymorphisms mediating functional change stand out to such an extent that evolutionary context provides a useful signal for identifying the molecular basis of drug resistance in malaria parasites, a finding that is of relevance to both genome-wide and candidate gene studies in this genus. © 2011 Gardner et al; licensee BioMed Central Ltd

Exploring young people's perspectives on mental health support: A qualitative study across three geographical areas in England, UK

Improving young people's (YP) mental health and well-being is a global public health priority. Despite continued commitment within the UK policy agenda to improve the mental health and well-being of YP, the incidence of mental health issues continues to rise. This has been further compounded by the outbreak of COVID-19 which has disproportionately affected YP in the most socioeconomically disadvantaged areas. Understanding YP's perspectives on what supports their mental health is important to develop policies that meet their needs. We conducted focus groups (n = 18 with 42 YP aged 13–21) in three geographical areas with high levels of deprivation in England, UK. Recruited through six local youth organisations, each group of YP took part in three interlinked focus groups designed to explore their perceptions of what impacts their health in their local area, and their understandings of health inequalities through participatory methods. Throughout their discussions, YP foregrounded the significance of mental health and mental health support structures. YP perceived challenges to accessing mental health provision and an unmet need for support within their local communities. Alongside this, YP consistently highlighted the importance of youth groups for promoting good mental health and mitigating challenges to poor mental health. However, ongoing cuts to the voluntary sector and universal services continue to impact areas and individuals in the greatest need. In the face of deficits in formal mental health support, our findings highlight the pressing need for increased investment in services focused on prevention (such as youth groups) in areas of high deprivation

Dihydroartemisinin-piperaquine versus chloroquine to treat vivax malaria in Afghanistan: an open randomized, non-inferiority, trial

BACKGROUND: Afghanistan's national guidelines recommend chloroquine for the treatment of Plasmodium vivax infection, the parasite responsible for the majority of its malaria burden. Chloroquine resistance in P. vivax is emerging in Asia. Therapeutic responses across Afghanistan have not been evaluated in detail. METHODS: Between July 2007 and February 2009, an open-label, randomized controlled trial of chloroquine and dihydroartemisinin-piperaquine in patients aged three months and over with slide-confirmed P. vivax mono-infections was conducted. Consistent with current national guidelines, primaquine was not administered. Subjects were followed up daily during the acute phase of illness (days 0-3) and weekly until day 56. The primary endpoint was the overall cumulative parasitological failure rate at day 56 after the start of treatment, with the hypothesis being that dihydroartemisinin-piperaquine was non-inferior compared to chloroquine (Delta = 5% difference in proportion of failures). RESULTS: Of 2,182 individuals with positive blood films for P. vivax, 536 were enrolled in the trial. The day 28 cure rate was 100% in both treatment groups. Parasite clearance was more rapid with dihydroartemisinin-piperaquine than chloroquine. At day 56, there were more recurrent infections in the chloroquine arm (8.9%, 95% CI 6.0-13.1%) than the dihydroartemisinin-piperaquine arm (2.8%, 95% CI 1.4-5.8%), a difference in cumulative recurrence rate of 6.1% (2-sided 90%CI +2.6 to +9.7%). The log-rank test comparing the survival curves confirmed the superiority of dihydroartemisinin-piperaquine over chloroquine (p = 0.003). Multivariate analysis showed that a lower initial haemoglobin concentration was also independently associated with recurrence. Both regimens were well tolerated and no serious adverse events were reported. CONCLUSIONS: Chloroquine remains an efficacious treatment for the treatment of vivax malaria in Afghanistan. In a setting where radical therapy cannot be administered, dihydroartemisinin-piperaquine provides additional benefit in terms of post-treatment prophylaxis, reducing the incidence of recurrence from 4-8 weeks after treatment

Diagnosing Severe Falciparum Malaria in Parasitaemic African Children: A Prospective Evaluation of Plasma PfHRP2 Measurement.

In African children, distinguishing severe falciparum malaria from other severe febrile illnesses with coincidental Plasmodium falciparum parasitaemia is a major challenge. P. falciparum histidine-rich protein 2 (PfHRP2) is released by mature sequestered parasites and can be used to estimate the total parasite burden. We investigated the prognostic significance of plasma PfHRP2 and used it to estimate the malaria-attributable fraction in African children diagnosed with severe malaria. Admission plasma PfHRP2 was measured prospectively in African children (from Mozambique, The Gambia, Kenya, Tanzania, Uganda, Rwanda, and the Democratic Republic of the Congo) aged 1 month to 15 years with severe febrile illness and a positive P. falciparum lactate dehydrogenase (pLDH)-based rapid test in a clinical trial comparing parenteral artesunate versus quinine (the AQUAMAT trial, ISRCTN 50258054). In 3,826 severely ill children, Plasmadium falciparum PfHRP2 was higher in patients with coma (p = 0.0209), acidosis (p<0.0001), and severe anaemia (p<0.0001). Admission geometric mean (95%CI) plasma PfHRP2 was 1,611 (1,350-1,922) ng/mL in fatal cases (n = 381) versus 1,046 (991-1,104) ng/mL in survivors (n = 3,445, p<0.0001), without differences in parasitaemia as assessed by microscopy. There was a U-shaped association between log(10) plasma PfHRP2 and risk of death. Mortality increased 20% per log(10) increase in PfHRP2 above 174 ng/mL (adjusted odds ratio [AOR] 1.21, 95%CI 1.05-1.39, p = 0.009). A mechanistic model assuming a PfHRP2-independent risk of death in non-malaria illness closely fitted the observed data and showed malaria-attributable mortality less than 50% with plasma PfHRP2≤174 ng/mL. The odds ratio (OR) for death in artesunate versus quinine-treated patients was 0.61 (95%CI 0.44-0.83, p = 0.0018) in the highest PfHRP2 tertile, whereas there was no difference in the lowest tertile (OR 1.05; 95%CI 0.69-1.61; p = 0.82). A limitation of the study is that some conclusions are drawn from a mechanistic model, which is inherently dependent on certain assumptions. However, a sensitivity analysis of the model indicated that the results were robust to a plausible range of parameter estimates. Further studies are needed to validate our findings. Plasma PfHRP2 has prognostic significance in African children with severe falciparum malaria and provides a tool to stratify the risk of "true" severe malaria-attributable disease as opposed to other severe illnesses in parasitaemic African children

Plasma concentration of parasite DNA as a measure of disease severity in falciparum malaria.

In malaria-endemic areas, Plasmodium falciparum parasitemia is common in apparently healthy children and severe malaria is commonly misdiagnosed in patients with incidental parasitemia. We assessed whether the plasma Plasmodium falciparum DNA concentration is a useful datum for distinguishing uncomplicated from severe malaria in African children and Asian adults. P. falciparum DNA concentrations were measured by real-time polymerase chain reaction (PCR) in 224 African children (111 with uncomplicated malaria and 113 with severe malaria) and 211 Asian adults (100 with uncomplicated malaria and 111 with severe malaria) presenting with acute falciparum malaria. The diagnostic accuracy of plasma P. falciparum DNA concentrations in identifying severe malaria was 0.834 for children and 0.788 for adults, similar to that of plasma P. falciparum HRP2 levels and substantially superior to that of parasite densities (P < .0001). The diagnostic accuracy of plasma P. falciparum DNA concentrations plus plasma P. falciparum HRP2 concentrations was significantly greater than that of plasma P. falciparum HRP2 concentrations alone (0.904 for children [P = .004] and 0.847 for adults [P = .003]). Quantitative real-time PCR measurement of parasite DNA in plasma is a useful method for diagnosing severe falciparum malaria on fresh or archived plasma samples

Young people’s views and experience of diet-related inequalities in England (UK): a qualitative study

Inequalities in diets contribute to overall inequalities in health. Economic inequality and inequalities in access to healthy food are key drivers of poor diet and ill health among young people (YP). Despite mounting evidence of structural barriers to healthy eating, less is known about how YP view and experience these inequalities where they live, and how to address them. To explore YP's perspectives on the drivers of diet-related health inequalities, we conducted three interlinked focus groups with YP aged 13-21 years from six youth groups across three geographical areas in England. We analysed the data inductively and deductively using reflexive thematic analysis and generated themes by examining how social structure, context and agency interact and impact YP's diet. YP were aware of how inequalities in employment conditions impact their families' income and ability to eat a healthy diet. They cited the high availability of hot food takeaways in their local areas as a significant barrier to healthy eating but did not support closing or restricting these outlets. They held strong views on policies to tackle diet inequality and showed a nuanced understanding of the strengths and limitations of universal and targeted approaches. Our study showed that YP have an awareness and understanding of food as important in relation to health, and of diet-related inequalities. However, further efforts are needed to shape and promote policies that resonate with YP and address both their health and wider social concerns