Differential alveolar epithelial injury and protein expression in pneumococcal pneumonia

RATIONALE: Streptococcus pneumoniae is a major cause of community- acquired pneumonia and its damaging effects on lung tissue can be extensive. The alveolar epithelium consists of alveolar type I (ATI) cells, involved in gas exchange, ATII cells, which are progenitor cells which secrete surfactant. Cell- specific marker proteins can be used to look at targeted epithelial injury by measurement in broncho -alveolar lavage (BAL) fluid, and expression of cell- specific proteins in lung tissue can be used to identify changes in cell population and functionality. The initial purpose of this thesis was to examine differential alveolar epithelial injury in pneumococcal pneumonia.RESULTS: Non-lethal rat models of acute (24 hours), resolving (72 hours) and recovering (3 weeks) pneumococcal pneumonia were set up, by way of intratracheal inoculation of wildtype D39 S. pneumoniae. Models were characterised by bacterial clearance with an acute inflammatory response and damage to the air-blood barrier that was resolving by 72 hours. Lungs were histologically normal after 3 weeks. Assessment of ATI cell- specific protein RTI40 demonstrated possible regulation in protein expression in both BAL fluid and lung tissue, rendering it inappropriate as a marker of injury in this model, and expression differed from that of other ATI cell- specific proteins. A new method of quantifying damaged ATII cells, using cell- specific proteins APN /MMC4, RTH70 and Pro -SP -C, showed targeted injury to these cells by 24 hours, which was shown to be resolving by 72 hours. Differential expression of ATII cell- specific surfactant proteins cytoplasmic Pro -SP -C and secreted SP -D was identified. Subsequent study to elucidate the mechanism of this differential protein expression compared the initial study with other models of lung infection. To determine the effect of pneumococcal toxin pneumolysin, PLN -A pneumolysin- deficient bacteria were used. Results showed that changes in expression of RTI40 and SP -D were not dependent on pneumolysin production. Further investigation to determine the extent that differential protein expression was characteristic of other Gram -positive infections S. aureus, wildtype 8325 -4 strain was used. Results demonstrated that differential expression of RTI40 was specific to pneumococcal ii infection but that expression of SP -D was common to other Gram -positive infections. To further explore the mechanism, in vitro bacterial co- culture experiments were carried out using S. pneumoniae D39 and the SV40 -T2 alveolar epithelial cell line, to establish if the observation was caused by a direct effect by bacteria or bacterial products. These showed that expression of RTI40 and SP -D were not altered by S. pneumoniae alone.CONCLUSIONS: Pneumococcal pneumonia induces specific injury to ATII cells and differential protein expression in both ATI and ATII cells. Expression of RTI40 is specific to the pneumococcus but expression of SP -D is common to other Gram -positive bacteria. Expression of neither protein was mediated by pneumolysin or by direct interaction of bacteria or bacterial products. These results provide valuable insight into host response to bacterial pathogens

Instrumental variable meta-analysis of randomised trials of epidural analgesia in labour to adjust for non-compliance

Objective: Intention-to-treat analysis of randomised controlled trials may cause bias towards the null where non-compliance with the allocated intervention occurs. Instrumental variable analysis allows estimation of the causal effect adjusted for non-compliance. The aim of this study is to compare intention-to-treat and instrumental variable meta-analysis of the association between epidural analgesia in labour and caesarean section. Study design and Setting: The study was restricted to 27 trials in a recent Cochrane Systematic Review. For trials with data on compliance, the association between epidural analgesia in labour and caesarean section was calculated using intention-to-treat analysis and instrumental variable analysis. Fixed-effects meta-analysis was used to calculate pooled risk ratios. Results: In 18 trials with data on compliance, 23% of women allocated to epidural analgesia did not comply and 27% of women allocated to the control received epidural analgesia. Data on outcomes in non-compliant groups were available for 10 trials. The pooled risk ratio for caesarean section following epidural analgesia in labour was 1.37 (95% CI 1.00-1.89, p=0.049) using instrumental variable analysis compared to 1.19 (95% CI 0.93-1.51, p=0.16) using intention-to-treat analysis. Conclusion: Intention-to-treat meta-analysis underestimates the effect of receiving epidural analgesia in labour on caesarean section compared to instrumental variable meta-analysis.NHMR

Intrahepatic cholestasis of pregnancy is not associated with stillbirth in an Australian maternity population

Dissertação de mestrado em Relações Internacionais (Estudos da Paz e da Segurança), apresentada à Faculdade de Economia da Universidade de CoimbraNo seguimento de experiências de violência extrema, no contexto de regimes políticos autoritários e violações sistemáticas de direitos humanos, algumas sociedades são confrontadas com questões relativas ao legado desse passado de violência, cujo impacto se faz sentir diretamente ao nível dos seus processos de (re)conciliação e reconstrução pós-conflito: o que será lembrado e esquecido, na construção da memória e verdade(s) sobre o conflito, e na transmissão do conhecimento às gerações futuras? O que deve acontecer aos indivíduos que planearam e aos que exerceram a violência? Que tipo de crimes serão julgados? Que tipo de processos judiciais e mecanismos de reparação serão estabelecidos e com que propósitos? Como é que uma sociedade pode (re)estabelecer os seus laços sociais intra-comunitários e até que ponto é que indivíduos que se percecionam mutuamente como inimigos alguma vez se poderão reconciliar? Estas são questões relacionadas com o fenómeno de justiça de transição, que se tem vindo a estabelecer enquanto norma global para as sociedades lidarem com o passado. A justiça de transição não só é uma área pouco teorizada como a sua teoria e prática dependem, em larga medida, de pressupostos adquiridos e partilhados com o modelo liberal internacional de construção da paz (peacebuilding). Esta dissertação procura problematizar mais especificamente um destes pressupostos, a dicotomia “vítimaperpetrador” e os processos de categorização inerentes ao modelo dominante de justiça de transição, em geral, tal como este é pensado e implementado ao nível internacional e nacional. Com base no estudo de caso do Ruanda, o nosso objetivo é demonstrar as insuficiências e limitações desta visão dicotómica para interpretar dinâmicas profundas de conflito considerando, ao invés, a diversidade de experiências de violência e vitimização que esta dicotomia exclui e refletindo sobre o seu impacto nas perspectivas de (re)conciliação pós-conflito, em particular da sociedade Ruandesa. De forma a atingir o objetivo a que nos propomos, a análise desta dissertação será orientada pela seguinte pergunta de partida: de que forma, no contexto de sociedades pós-conflito, como o Ruanda, pode uma narrativa de vitimização dominante ser desafiada por excluir uma diversidade de experiências de vitimização e violência, e que repercussões pode esta contestação originar para as perspectivas de (re)conciliação nesta sociedade? A nossa análise estará alicerçada em três hipóteses: (i) a dicotomia “vítima-perpetrator” é um elemento fundamental das iniciativas de transição pós-conflito apoiados pela ONU e implementados no contexto de intervenções internacionais; (ii) o Ruanda no pósgenocídio é caracterizado por uma narrativa nacional dominante de vitimização, baseada numa dicotomia “vítima-perpetrator” que é insuficiente para compreender a diversidade de experiências de violência e vitimização vivida por diferentes grupos sociais, excluindoas e deslegitimando-as; e (iii) os processos de justiça de transição orientados segundo esta dicotomia provocam novas formas de re-vitimização, por um lado, invisibilizando e deslegitimando certas experiências de violência e vitimização e, por outro lado, tomando estas categorias socio-políticas como absolutas, limitando assim a agência política dos indivíduos e a sua (re)integração social, colocando em causa o processo de (re)conciliação em sociedades divididas em geral, e na Ruandesa em particular. A validação destas hipóteses será baseada numa abordagem qualitativa à investigação, com base na interpretação qualitativa de informação textual recolhida através de fontes primárias e secundárias, e também na análise de discurso. O enquadramento teórico e conceptual com base no qual articularemos a nossa crítica combina contributos teóricos de duas disciplinas distintas mas complementares: a psicologia social, mais precisamente o trabalho de Carlos Beristain sobre a abordagem psicosocial, e a teoria das relações internacionais, especificamente a vertente mais crítica da abordagem construtivista. Da nossa análise decorreu a validação das nossas hipóteses iniciais, sendo que demonstrámos assim como a dicotomia “vítima-perpetrator” se tem tornado um elemento fundamental nas iniciativas de justiça de transição apoiadas pela ONU; discutimos e detalhámos as narrativas dominantes de justiça de transição e vitimização estabelecidas no Ruanda e as suas dinâmicas de exclusão e, por último, refletimos sobre como os processos de justiça de transição orientados por esta dicotomia promovem processos de revitimização e limitam as perspectivas de longo prazo de reconciliação em sociedades divididas, como exemplificado pelo Ruanda no pós-genocídio.Following experiences of extreme violence, in the context of authoritarian political regimes and systematic human rights violations, societies are faced with questions regarding the legacy of that past of violence, which directly impact on the processes of (re)conciliation and post-conflict rebuilding: what will be remembered and forgotten, in the construction of memory and truth(s) relating to the conflict, and in the transmission of knowledge to younger generations? What should happen to those individuals who planned and those who enacted the violence? What will be the range of crimes under investigation? What kind of judicial processes and mechanisms for reparations will be established and with what purposes? How can a community (re)establish its social intra-community ties and to what extent and in which way can individuals who perceive each other as enemies ever reconcile? These questions fall within the scope of the phenomenon of transitional justice, which has been establishing itself as a global norm on how societies should deal with the past. Not only is the field of transitional justice under theorized but its dominant discourse on theory and praxis relies heavily on core assumptions taken for granted, many of which borrowed from liberal peacebuilding. Our dissertation seeks to problematize one of these, in particular, the “victim-perpetrator” dichotomy and the categorizing inherent to the dominant transitional justice model thought of and implemented at both international and national levels. Drawing on Rwanda as a case study, this dissertation will aim at demonstrating the insufficiencies and limitations of this dichotomised view in understanding deeper conflict dynamics, by looking into the diversity of violence and victimhood experiences that this dichotomy excludes and by reflecting upon its impact on the prospects of post-conflict (re)conciliation, specifically with regards to contemporary Rwandan society. In order to achieve our proposed aim, the analysis in this dissertation will be guided by the following research question: In what way, in the context of a post-conflict society such as Rwanda, can an established dominant victimhood narrative be challenged for excluding the diversity of victimization and violence experiences, and what repercussions may that dispute have on the prospects of (re)conciliation in this society? Our analysis will be grounded on three working hypotheses: (i) the dichotomy “victim-perpetrator” is a fundamental element in UN-sanctioned post-conflict transition Initiatives implemented in the context of international interventions; (ii) post -genocide Rwanda is characterized by a national dominant victimhood narrative, based on a “victim-perpetrator” dichotomy which is insufficient to understand the full diversity of violence and victimhood experiences from different social groups, therefore excluding and delegitimizing them; and (iii) transitional justice processes framed by this dichotomy promote new forms of victimization, on the one hand, by making invisible (and, therefore, illegitimate) certain experiences of violence and victimhood and, on the other hand, by essentializing these sociopolitical categories, which ends up limiting individuals’ political agency and social reintegration, hindering the reconciliation process in divided societies and, particularly, in Rwanda. The validation of these hypotheses will be based on a qualitative research approach, in this way relying on the qualitative interpretation of textual (qualitative) data collected both from the literature and from primary evidence as well as discourse analysis. The theoretical and conceptual framework supporting our critique combines contributions from two distinct but, complementary fields of study: social psychology, in particular the work of Carlos Beristain on the psychosocial approach, and international relations theory, drawing on the more critical strand of constructivism. Our discussion successfully validated our three initial hypotheses, therefore asserting how the “victim-perpetrator” dichotomy has become a fundamental element in UN-sanctioned transit ional justice initiatives; discussing and detailing the dominant transitional justice and victimhood narratives in Rwanda and their dynamics of exclusion and, finally, reflecting on how transitional justice processes framed by this dichotomy promote re-victimization and hinder long-term reconciliation in divided societies such as post-genocide Rwanda

Structural Features Essential to the Antimicrobial Functions of Human SPLUNC1

SPLUNC1 is an abundantly secreted innate immune protein in the mammalian respiratory tract that exerts bacteriostatic and antibiofilm effects, binds to lipopolysaccharide (LPS), and acts as a fluid-spreading surfactant. Here, we unravel the structural elements essential for the surfactant and antimicrobial functions of human SPLUNC1 (short palate lung nasal epithelial clone 1). A unique α-helix (α4) that extends from the body of SPLUNC1 is required for the bacteriostatic, surfactant, and LPS binding activities of this protein. Indeed, we find that mutation of just four leucine residues within this helical motif to alanine is sufficient to significantly inhibit the fluid spreading abilities of SPLUNC1, as well as its bacteriostatic actions against Gram-negative pathogens Burkholderia cenocepacia and Pseudomonas aeruginosa. Conformational flexibility in the body of SPLUNC1 is also involved in the bacteriostatic, surfactant, and LPS binding functions of the protein as revealed by disulfide mutants introduced into SPLUNC1. In addition, SPLUNC1 exerts antibiofilm effects against Gram-negative bacteria, although α4 is not involved in this activity. Interestingly, though, the introduction of surface electrostatic mutations away from α4 based on the unique dolphin SPLUNC1 sequence, and confirmed by crystal structure, is shown to impart antibiofilm activity against Staphylococcus aureus, the first SPLUNC1-dependent effect against a Gram-positive bacterium reported to date. Together, these data pinpoint SPLUNC1 structural motifs required for the antimicrobial and surfactant actions of this protective human protein

Sexual Health Education from the Perspective of School Staff: Implications for Adoption and Implementation of Effective Programs in Middle School

Introduction: US teens are having sex early; however, the vast majority of schools do not implement evidence-based sexual health education (SHE) programs that could delay sexual behavior and/or reduce risky behavior. This study examines middle school staff’s knowledge, attitudes, barriers, self-efficacy, and perceived support (psychosocial factors known to influence SHE program adoption and implementation). Methods: Professional school staff from 33 southeast Texas middle schools completed an internet or paper-based survey. Prevalence estimates for psychosocial variables were computed for the total sample. Chi-square and t-test analyses examined variation by demographic factors. Results: Almost 70% of participants were female, 37% white, 42% black, 16% Hispanic; 20% administrators, 15% nurses/counselors, 31% non-physical education/non-health teachers, 28% physical education/health teachers; mean age = 42.78 years (SD = 10.9). Over 90% favored middle school SHE, and over 75% reported awareness of available SHE curricula or policies. More than 60% expressed confidence for discussing SHE. Staff perceived varying levels of administrator (28%-56%) support for SHE and varying levels of support for comprehensive sex education from outside stakeholders (e.g., parents, community leaders) (42%-85%). Overall, results were more favorable for physical education/health teachers, nurses/counselors, and administrators (when compared to non-physical education/non-health teachers) and individuals with experience teaching SHE. Few significant differences were observed by other demographic factors. Conclusions: Overall, study results were extremely positive, which may reflect a high level of readiness among school staff for adopting and implementing effective middle school SHE programs. Study results highlight the importance of several key action items for schools

Clinical risk scores for predicting stroke-associated pneumonia: A systematic review:A systematic review

Purpose Several risk stratification scores for predicting stroke-associated pneumonia have been derived. We aimed to evaluate the performance and clinical usefulness of such scores for predicting stroke-associated pneumonia. Method A systematic literature review was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, with application of the Quality Assessment of Diagnostic Accuracy-2 tool. Published studies of hospitalised adults with ischaemic stroke, intracerebral haemorrhage, or both, which derived and validated an integer-based clinical risk score, or externally validated an existing score to predict occurrence of stroke-associated pneumonia, were considered and independently screened for inclusion by two reviewers. Findings We identified nine scores, from eight derivation cohorts. Age was a component of all scores, and the NIHSS score in all except one. Six scores were internally validated and five scores were externally validated. The A2DS2 score (Age, Atrial fibrillation, Dysphagia, Severity [NIHSS], Sex) was the most externally validated in 8 independent cohorts. Performance measures were reported for eight scores. Discrimination tended to be more variable in the external validation cohorts (C statistic 0.67–0.83) than the derivation cohorts (C statistic 0.74–0.85). Discussion Overall, discrimination and calibration were similar between the different scores. No study evaluated influence on clinical decision making or prognosis. Conclusion The clinical prediction scores varied in their simplicity of use and were comparable in performance. Utility of such scores for preventive intervention trials and in clinical practice remains uncertain and requires further study

Exploring the links between unhealthy eating behaviour and heavy alcohol use in the social, emotional and cultural lives of young adults (aged 18–25)::A qualitative research study

Alcohol use peaks in early adulthood and can contribute both directly and indirectly to unhealthy weight gain. This is the first qualitative study to explore the links between unhealthy eating behaviour and heavy alcohol use in the social, emotional and cultural lives of young adults. We conducted 45 in-depth interviews with 18–25-year-olds in North-East England to inform development of a dual-focused intervention to reduce health risk due to excess weight gain and alcohol use. Data were analysed thematically, following the principles of constant comparison, resulting in three intersecting themes: (1) how food and alcohol consumption currently link together for this population group; (2) influences upon linked eating and drinking behaviours and (3) young adults’ feelings and concerns about linked eating and drinking behaviours. Socio-cultural, physical and emotional links between food and alcohol consumption were an unquestioned norm among young adults. Eating patterns linked to alcohol use were not tied only to hunger, but also to sociability, traditions and identity. Young adults conceptualised and calculated risks to weight, appearance and social status, rather than to long-term health. This study is the first to evidence the deeply interconnected nature of food and alcohol consumption for many young adults. Findings have important implications for intervention development, UK public health policy and practice, and point to a need for similar research in other countries

Revising the structure of a new eicosanoid from human platelets to 8,9-11,12-diepoxy-13-hydroxy-eicosadienoic acid

Eicosanoids are critical mediators of fever, pain, and inflammation generated by immune and tissue cells. We recently described a new bioactive eicosanoid generated by cyclooxygenase-1 (COX-1) turnover during platelet activation that can stimulate human neutrophil integrin expression. On the basis of mass spectrometry (MS/MS and MS3), stable isotope labeling, and GC-MS analysis, we previously proposed a structure of 8-hydroxy-9,11-dioxolane eicosatetraenoic acid (DXA3). Here, we achieved enzymatic synthesis and 1H NMR characterization of this compound with results in conflict with the previously proposed structural assignment. Accordingly, by using LC-MS, we screened autoxidation reactions of 11-hydroperoxy-eicosatetraenoic acid (11-HpETE) and thereby identified a candidate sharing the precise reverse-phase chromatographic and MS characteristics of the platelet product. We optimized these methods to increase yield, allowing full structural analysis by 1H NMR. The revised assignment is presented here as 8,9–11,12-diepoxy-13-hydroxyeicosadienoic acid, abbreviated to 8,9–11,12-DiEp-13-HEDE or DiEpHEDE, substituted for the previous name DXA3. We found that in platelets, the lipid likely forms via dioxolane ring opening with rearrangement to the diepoxy moieties followed by oxygen insertion at C13. We present its enzymatic biosynthetic pathway and MS/MS fragmentation pattern and, using the synthetic compound, demonstrate that it has bioactivity. For the platelet lipid, we estimate 16 isomers based on our current knowledge (and four isomers for the synthetic lipid). Determining the exact isomeric structure of the platelet lipid remains to be undertaken

Partial Deletion of Chromosome 8 β-defensin Cluster Confers Sperm Dysfunction and Infertility in Male Mice

β-defensin peptides are a family of antimicrobial peptides present at mucosal surfaces, with the main site of expression under normal conditions in the male reproductive tract. Although they kill microbes in vitro and interact with immune cells, the precise role of these genes in vivo remains uncertain. We show here that homozygous deletion of a cluster of nine β-defensin genes (DefbΔ9) in the mouse results in male sterility. The sperm derived from the mutants have reduced motility and increased fragility. Epididymal sperm isolated from the cauda should require capacitation to induce the acrosome reaction but sperm from the mutants demonstrate precocious capacitation and increased spontaneous acrosome reaction compared to wild-types but have reduced ability to bind the zona pellucida of oocytes. Ultrastructural examination reveals a defect in microtubule structure of the axoneme with increased disintegration in mutant derived sperm present in the epididymis cauda region, but not in caput region or testes. Consistent with premature acrosome reaction, sperm from mutant animals have significantly increased intracellular calcium content. Thus we demonstrate in vivo that β-defensins are essential for successful sperm maturation, and their disruption leads to alteration in intracellular calcium, inappropriate spontaneous acrosome reaction and profound male infertility