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1.
BMC Public Health ; 24(1): 2820, 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39402467

RESUMO

BACKGROUND: Antimicrobial resistance is a global patient safety priority and inappropriate antimicrobial use is a key contributing factor. Evidence have shown that delayed (back-up) antibiotic prescriptions (DP) are an effective and safe strategy for reducing unnecessary antibiotic consumption but its use is controversial. METHODS: We conducted a realist review to ask why, how, and in what contexts general practitioners (GPs) use DP. We searched five electronic databases for relevant articles and included DP-related data from interviews with healthcare professionals in a related study. Data were analysed using a realist theory-driven approach - theorising which context(s) influenced (mechanisms) resultant outcome(s) (context-mechanism-outcome-configurations: CMOCs). RESULTS: Data were included from 76 articles and 41 interviews to develop a program theory comprising nine key and 56 related CMOCs. These explain the reasons for GPs' tolerance of risk to different uncertainties and how these may interact with GPs' work environment, self-efficacy and perceived patient concordance to make using DP as a safety-net or social tool more or less likely, at a given time-point. For example, when a GP uses clinical scores or diagnostic tests: a clearly high or low score/test result may mitigate scientific uncertainty and lead to an immediate or no antibiotic decision; an intermediary result may provoke hermeneutic (interpretation-related) uncertainty and lead to DP becoming preferred and used as a safety net. Our program theory explains how DP can be used to mitigate some uncertainties but also provoke or exacerbate others. CONCLUSION: This review explains how, why and in what contexts GPs are more or less likely to use DP, as well as various uncertainties GPs face which DP may mitigate or provoke. We recommend that efforts to plan and implement interventions to optimise antibiotic prescribing in primary care consider these uncertainties and the contexts when DP may be (dis)preferred over other interventions to reduce antibiotic prescribing. We also recommend the following and have included example activities for: (i) reducing demand for immediate antibiotics; (ii) framing DP as an 'active' prescribing option; (iii) documenting the decision-making process around DP; and (iv) facilitating social and system support.


Assuntos
Antibacterianos , Padrões de Prática Médica , Atenção Primária à Saúde , Humanos , Antibacterianos/uso terapêutico , Incerteza , Padrões de Prática Médica/estatística & dados numéricos , Clínicos Gerais/psicologia , Prescrições de Medicamentos/estatística & dados numéricos , Prescrição Inadequada/prevenção & controle
2.
Health Expect ; 26(3): 1349-1357, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36945787

RESUMO

INTRODUCTION: A range of nonpharmaceutical public health interventions has been introduced in many countries following the rapid spread of Covid-19 since 2020, including recommendations or mandates for the use of face masks or coverings in the community. While the effectiveness of face masks in reducing Covid-19 transmission has been extensively discussed, scant attention has been paid to the lived experience of those wearing face masks. METHOD: Drawing on 40 narrative interviews with a purposive sample of people in the United Kingdom, with a particular focus on marginalised and minoritized groups, our paper explores experiences of face mask use during the pandemic. RESULTS: We find that face masks have a range of societal, health and safety impacts, and prompted positive and negative emotional responses for users. We map our findings onto Lorenc and Oliver's framework for intervention risks. We suggest that qualitative data offer particular insights into the experiences of public health interventions, allowing the potential downsides and risks of interventions to be more fully considered and informing public health policies that might avoid inadvertent harm, particularly towards marginalised groups. PATIENT OR PUBLIC CONTRIBUTION: The study primarily involved members of the public in the conduct of the research, namely through participation in interviews (email and telephone). The conception for the study involved extensive discussions on social media with a range of people, and we received input and ideas from presentations we delivered on the preliminary analysis.


Assuntos
COVID-19 , Máscaras , Humanos , Pandemias/prevenção & controle , COVID-19/prevenção & controle , Emoções , Pesquisa Qualitativa
3.
BMC Health Serv Res ; 23(1): 183, 2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36810110

RESUMO

BACKGROUND: The limited health and social care infrastructure that existed in the 1970s in Cambodia was destroyed due to the Khmer Rouge. Mental Health service infrastructures have developed in Cambodia in the last twenty five years, however, they have been shaped significantly by very limited funding being made available for human resources, support services and research. The lack of research on Cambodia's mental health systems and services is a significant barrier to the development of evidence-based mental health policies and practice. In order to address this barrier, effective research and development strategies are needed in Cambodia, which are based on locally well-informed research priorities. There are many possibilities for mental health research in LMIC countries such as Cambodia, therefore focused research priorities in these areas are needed to guide future research investment. This paper is the result of the development of international collaborative workshops, which focused on service mapping and research priority setting in the field of mental health in Cambodia. METHODS: A nominal group technique was used to gather ideas and insights from a range of key mental health service stakeholders in Cambodia. RESULTS: The key issues in service provisions for people with mental health issues and disorders, the interventions and programmes of support available, and currently needed, were identified. This paper also identifies five key mental health research priority areas which could form the basis for effective mental health research and development strategies in Cambodia. CONCLUSION: There is a clear need for the Cambodian government to devise a clear policy framework for health research. This framework could focus on the five research domains identified in this paper and could be incorporated within its National Health Strategic plans. The implementation of this approach would likely lead to the development of an evidence base which would allow the development of effective and sustainable strategies for mental health problem prevention and intervention. This would also contribute to promote the Cambodian government's capacity to take the deliberate, concrete, and targeted steps necessary to address the complex mental health needs of its population.


Assuntos
Serviços de Saúde Mental , Humanos , Camboja/epidemiologia , Política de Saúde , Saúde Mental , Pesquisa
4.
Mol Ther ; 29(4): 1585-1601, 2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33333291

RESUMO

Suicide gene therapies provide a unique ability to target cancer cells selectively, often based on modification of viral tropism or transcriptional regulation of therapeutic gene expression. We designed a novel suicide gene therapy approach wherein the gene product (herpes simplex virus thymidine kinase or yeast cytosine deaminase) is phosphorylated and stabilized in expression by the extracellular signal-regulated kinase (ERK), which is overactive in numerous cancers with elevated expression or mutation of receptor tyrosine kinases or the GTPase RAS. In contrast to transcriptional strategies for selectivity, regulation of protein stability by ERK allows for high copy expression via constitutive viral promoters, while maintaining tumor selectivity in contexts of elevated ERK activity. Thus, our approach turns a signaling pathway often coopted by cancer cells for survival into a lethal disadvantage in the presence of a chimeric protein and prodrug, as highlighted by a series of in vitro and in vivo examples explored here.


Assuntos
Citosina Desaminase/genética , Genes Transgênicos Suicidas/genética , Terapia Genética , Neoplasias/terapia , Timidina Quinase/genética , Animais , Citosina Desaminase/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/genética , Vetores Genéticos/genética , Xenoenxertos , Humanos , Camundongos , Neoplasias/genética , Neoplasias/patologia , Simplexvirus/enzimologia , Timidina Quinase/farmacologia , Células Tumorais Cultivadas , Proteínas ras/genética
5.
Sociol Health Illn ; 44(9): 1481-1499, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36040759

RESUMO

The use of face masks and coverings has been a central component of efforts to mitigate the impact of the COVID-19 pandemic and has been legally mandated in some countries. Most academic studies to date, however, have focussed primarily on its effectiveness in reducing SARS-CoV-2 transmission, largely neglecting the social dimensions of mask mandates. In this narrative interview-based study, we consider experiences of face masks, with a particular focus on groups considered to be at a potential disadvantage from compulsory masking. Drawing on 40 telephone, video-call and e-mail interviews, we highlight the impact of inconsistent communication and the notion of mask wearing as an act of altruism on participants' experiences. In particular, we show how intolerance towards individuals who did not wear masks could result in stigma and exclusion, regardless of the legitimacy of their reasons. We suggest that more is needed to mitigate the 'dark side' of discourses of collective effort and altruism at a time of societal stress and fracture, and to account for the needs and interests of groups for whom compulsory masking may result in further marginalisation.


Assuntos
COVID-19 , Máscaras , Humanos , Pandemias/prevenção & controle , SARS-CoV-2 , Pesquisa Qualitativa
6.
Infect Immun ; 89(12): e0034821, 2021 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-34543122

RESUMO

Helicobacter pylori VacA is a secreted toxin that assembles into water-soluble oligomeric structures and forms anion-selective membrane channels. Acidification of purified VacA enhances its activity in cell culture assays. Sites of protomer-protomer contact within VacA oligomers have been identified by cryoelectron microscopy, and in the current study, we validated several of these interactions by chemical cross-linking and mass spectrometry. We then mutated amino acids at these contact sites and analyzed the effects of the alterations on VacA oligomerization and activity. VacA proteins with amino acid charge reversals at interprotomer contact sites retained the capacity to assemble into water-soluble oligomers and retained cell-vacuolating activity. Introduction of paired cysteine substitutions at these sites resulted in formation of disulfide bonds between adjacent protomers. Negative-stain electron microscopy and single-particle two-dimensional class analysis revealed that wild-type VacA oligomers disassemble when exposed to acidic pH, whereas the mutant proteins with paired cysteine substitutions retain an oligomeric state at acidic pH. Acid-activated wild-type VacA caused vacuolation of cultured cells, whereas acid-activated mutant proteins with paired cysteine substitutions lacked cell-vacuolating activity. Treatment of these mutant proteins with both low pH and a reducing agent resulted in VacA binding to cells, VacA internalization, and cell vacuolation. Internalization of a nonoligomerizing mutant form of VacA by host cells was detected without a requirement for acid activation. Collectively, these results enhance our understanding of the molecular interactions required for VacA oligomerization and support a model in which toxin activity depends on interactions of monomeric VacA with host cells.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Conformação Proteica , Multimerização Proteica , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Relação Estrutura-Atividade
7.
Infect Immun ; 89(4)2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33526561

RESUMO

Helicobacter pylori encounters a wide range of pH within the human stomach. In a comparison of H. pylori cultured in vitro under neutral or acidic conditions, about 15% of genes are differentially expressed, and corresponding changes are detectable for many of the encoded proteins. The ArsRS two-component system (TCS), comprised of the sensor kinase ArsS and its cognate response regulator ArsR, has an important role in mediating pH-responsive changes in H. pylori gene expression. In this study, we sought to delineate the pH-responsive ArsRS regulon and further define the role of ArsR in pH-responsive gene expression. We compared H. pylori strains containing an intact ArsRS system with an arsS null mutant or strains containing site-specific mutations of a conserved aspartate residue (D52) in ArsR, which is phosphorylated in response to signals relayed by the cognate sensor kinase ArsS. We identified 178 genes that were pH-responsive in strains containing an intact ArsRS system but not in ΔarsS or arsR mutants. These constituents of the pH-responsive ArsRS regulon include genes involved in acid acclimatization (ureAB, amidases), oxidative stress responses (katA, sodB), transcriptional regulation related to iron or nickel homeostasis (fur, nikR), and genes encoding outer membrane proteins (including sabA, alpA, alpB, hopD [labA], and horA). When comparing H. pylori strains containing an intact ArsRS TCS with arsRS mutants, each cultured at neutral pH, relatively few genes are differentially expressed. Collectively, these data suggest that ArsRS-mediated gene regulation has an important role in H. pylori adaptation to changing pH conditions.


Assuntos
Regulação Bacteriana da Expressão Gênica , Helicobacter pylori/fisiologia , Concentração de Íons de Hidrogênio , Elementos de Resposta , Transativadores/metabolismo , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Humanos , Mutação , Proteoma , Proteômica/métodos , Transcrição Gênica
8.
BMC Fam Pract ; 22(1): 25, 2021 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-33485324

RESUMO

BACKGROUND: Trials have shown that delayed antibiotic prescriptions (DPs) and point-of-care C-Reactive Protein testing (POC-CRPT) are effective in reducing antibiotic use in general practice, but these were not typically implemented in high-prescribing practices. We aimed to explore views of professionals from high-prescribing practices about uptake and implementation of DPs and POC-CRPT to reduce antibiotic use. METHODS: This was a qualitative focus group study in English general practices. The highest antibiotic prescribing practices in the West Midlands were invited to participate. Clinical and non-clinical professionals attended focus groups co-facilitated by two researchers. Focus groups were audio-recorded, transcribed verbatim and analysed thematically. RESULTS: Nine practices (50 professionals) participated. Four main themes were identified. Compatibility of strategies with clinical roles and experience - participants viewed the strategies as having limited value as 'clinical tools', perceiving them as useful only in 'rare' instances of clinical uncertainty and/or for those less experienced. Strategies as 'social tools' - participants perceived the strategies as helpful for negotiating treatment decisions and educating patients, particularly those expecting antibiotics. Ambiguities - participants perceived ambiguities around when they should be used, and about their impact on antibiotic use. Influence of context - various other situational and practical issues were raised with implementing the strategies. CONCLUSIONS: High-prescribing practices do not view DPs and POC-CRPT as sufficiently useful 'clinical tools' in a way which corresponds to the current policy approach advocating their use to reduce clinical uncertainty and improve antimicrobial stewardship. Instead, policy attention should focus on how these strategies may instead be used as 'social tools' to reduce unnecessary antibiotic use. Attention should also focus on the many ambiguities (concerns and questions) about, and contextual barriers to, using these strategies that need addressing to support wider and more consistent implementation.


Assuntos
Antibacterianos , Gestão de Antimicrobianos , Antibacterianos/uso terapêutico , Tomada de Decisão Clínica , Humanos , Padrões de Prática Médica , Pesquisa Qualitativa , Incerteza
9.
Infect Immun ; 88(6)2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32284370

RESUMO

Helicobacter pylori colonizes the gastric mucosa and secretes a pore-forming toxin (VacA). Two main types of VacA, m1 and m2, can be distinguished by phylogenetic analysis. Type m1 forms of VacA have been extensively studied, but there has been relatively little study of m2 forms. In this study, we generated H. pylori strains producing chimeric proteins in which VacA m1 segments of a parental strain were replaced by corresponding m2 sequences. In comparison to the parental m1 VacA protein, a chimeric protein (designated m2/m1) containing m2 sequences in the N-terminal portion of the m region was less potent in causing vacuolation of HeLa cells, AGS gastric cells, and AZ-521 duodenal cells and had reduced capacity to cause membrane depolarization or death of AZ-521 cells. Consistent with the observed differences in activity, the chimeric m2/m1 VacA protein bound to cells at reduced levels compared to the binding levels of the parental m1 protein. The presence of two strain-specific insertions or deletions within or adjacent to the m region did not influence toxin activity. Experiments with human gastric organoids grown as monolayers indicated that m1 and m2/m1 forms of VacA had similar cell-vacuolating activities. Interestingly, both forms of VacA bound preferentially to the basolateral surface of organoid monolayers and caused increased cell vacuolation when interacting with the basolateral surface compared to the apical surface. These data provide insights into functional correlates of sequence variation in the VacA midregion (m region).


Assuntos
Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Variação Genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/fisiologia , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Regulação Bacteriana da Expressão Gênica , Humanos , Domínios Proteicos , Multimerização Proteica , Transporte Proteico , Vacúolos/metabolismo , Vacúolos/ultraestrutura
10.
BMC Geriatr ; 20(1): 59, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-32059649

RESUMO

BACKGROUND: The aim of this study was to update and refine an algorithm, originally developed in Canada, to assist care home staff to manage residents with suspected infection in the United Kingdom care home setting. The infections of interest were urinary tract infections, respiratory tract infections and skin and soft tissue infection. METHOD: We used a multi-faceted process involving a literature review, consensus meeting [nominal group technique involving general practitioners (GPs) and specialists in geriatric medicine and clinical microbiology], focus groups (care home staff and resident family members) and interviews (GPs), alongside continual iterative internal review and analysis within the research team. RESULTS: Six publications were identified in the literature which met inclusion criteria. These were used to update the algorithm which was presented to a consensus meeting (four participants all with a medical background) which discussed and agreed to inclusion of signs and symptoms, and the algorithm format. Focus groups and interview participants could see the value in the algorithm, and staff often reported that it reflected their usual practice. There were also interesting contrasts between evidence and usual practice informed by experience. Through continual iterative review and analysis, the final algorithm was finally presented in a format which described management of the three infections in terms of initial assessment of the resident, observation of the resident and action by the care home staff. CONCLUSIONS: This study has resulted in an updated algorithm targeting key infections in care home residents which should be considered for implementation into everyday practice.


Assuntos
Tomada de Decisão Clínica , Medicina Baseada em Evidências , Instituição de Longa Permanência para Idosos , Infecções/diagnóstico , Infecções/tratamento farmacológico , Guias de Prática Clínica como Assunto , Idoso , Humanos , Casas de Saúde , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/tratamento farmacológico , Dermatopatias Infecciosas/diagnóstico , Dermatopatias Infecciosas/tratamento farmacológico , Infecções dos Tecidos Moles/diagnóstico , Infecções dos Tecidos Moles/tratamento farmacológico , Reino Unido , Infecções Urinárias/diagnóstico , Infecções Urinárias/tratamento farmacológico
11.
PLoS Genet ; 13(2): e1006611, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28182654

RESUMO

Germ cells contain non-membrane bound cytoplasmic organelles that help maintain germline integrity. In C. elegans they are called P granules; without them, the germline undergoes partial masculinization and aberrant differentiation. One key P-granule component is the Argonaute CSR-1, a small-RNA binding protein that antagonizes accumulation of sperm-specific transcripts in developing oocytes and fine-tunes expression of proteins critical to early embryogenesis. Loss of CSR-1 complex components results in a very specific, enlarged P-granule phenotype. In a forward screen to identify mutants with abnormal P granules, ten alleles were recovered with a csr-1 P-granule phenotype, eight of which contain mutations in known components of the CSR-1 complex (csr-1, ego-1, ekl-1, and drh-3). The remaining two alleles are in a novel gene now called elli-1 (enlarged germline granules). ELLI-1 is first expressed in primordial germ cells during mid-embryogenesis, and continues to be expressed in the adult germline. While ELLI-1 forms cytoplasmic aggregates, they occasionally dock, but do not co-localize with P granules. Instead, the majority of ELLI-1 aggregates accumulate in the shared germline cytoplasm. In elli-1 mutants, several genes that promote RNAi and P-granule accumulation are upregulated, and embryonic lethality, sterility, and RNAi resistance in a hypomorphic drh-3 allele is enhanced, suggesting that ELLI-1 functions with CSR-1 to modulate RNAi activity, P-granule accumulation, and post-transcriptional expression in the germline.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Grânulos Citoplasmáticos/metabolismo , Células Germinativas/metabolismo , Interferência de RNA , Fatores Genéricos de Transcrição/genética , Alelos , Animais , Animais Geneticamente Modificados , Sequência de Bases , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Microscopia de Fluorescência , Mutação , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores Genéricos de Transcrição/metabolismo
12.
Infect Immun ; 87(4)2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30692181

RESUMO

Helicobacter pylori VacA is a secreted pore-forming toxin that induces cell vacuolation in vitro and contributes to the pathogenesis of gastric cancer and peptic ulcer disease. We observed that purified VacA has relatively little effect on the viability of AGS gastric epithelial cells, but the presence of exogenous weak bases such as ammonium chloride (NH4Cl) enhances the susceptibility of these cells to VacA-induced vacuolation and cell death. Therefore, we tested the hypothesis that NH4Cl augments VacA toxicity by altering the intracellular trafficking of VacA or inhibiting intracellular VacA degradation. We observed VacA colocalization with LAMP1- and LC3-positive vesicles in both the presence and absence of NH4Cl, indicating that NH4Cl does not alter VacA trafficking to lysosomes or autophagosomes. Conversely, we found that supplemental NH4Cl significantly increases the intracellular stability of VacA. By conducting experiments using chemical inhibitors, stable ATG5 knockdown cell lines, and ATG16L1 knockout cells (generated using CRISPR/Cas9), we show that VacA degradation is independent of autophagy and proteasome activity but dependent on lysosomal acidification. We conclude that weak bases like ammonia, potentially generated during H. pylori infection by urease and other enzymes, enhance VacA toxicity by inhibiting toxin degradation.


Assuntos
Proteínas de Bactérias/metabolismo , Células Epiteliais/citologia , Mucosa Gástrica/citologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/metabolismo , Autofagia/efeitos dos fármacos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/toxicidade , Linhagem Celular , Sobrevivência Celular , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/microbiologia , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/microbiologia , Helicobacter pylori/química , Helicobacter pylori/genética , Humanos , Concentração de Íons de Hidrogênio , Muramidase/química , Muramidase/metabolismo , Estabilidade Proteica , Transporte Proteico , Proteólise
13.
Infect Immun ; 86(5)2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29531133

RESUMO

Helicobacter pylori, a Gram-negative bacterium, is a well-known risk factor for gastric cancer. H. pylori vacuolating cytotoxin A (VacA) is a secreted pore-forming toxin that induces a wide range of cellular responses. Like many other bacterial toxins, VacA has been hypothesized to utilize lipid rafts to gain entry into host cells. Here, we used giant plasma membrane vesicles (GPMVs) as a model system to understand the preferential partitioning of VacA into lipid rafts. We show that a wild-type (WT) toxin predominantly associates with the raft phase. Acid activation of VacA enhances binding of the toxin to GPMVs but is not required for raft partitioning. VacA mutant proteins with alterations at the amino terminus (resulting in impaired membrane channel formation) and a nonoligomerizing VacA mutant protein retain the ability to preferentially associate with lipid rafts. Consistent with these results, the isolated VacA p55 domain was capable of binding to lipid rafts. We conclude that the affinity of VacA for rafts is independent of its capacity to oligomerize or form membrane channels.


Assuntos
Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Helicobacter pylori/metabolismo , Helicobacter pylori/patogenicidade , Microdomínios da Membrana/metabolismo , Neoplasias Gástricas/patologia , Vacúolos/metabolismo , Interações Hospedeiro-Patógeno
14.
Development ; 142(10): 1745-55, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25968310

RESUMO

Germ granules (P granules) in C. elegans are required for fertility and function to maintain germ cell identity and pluripotency. Sterility in the absence of P granules is often accompanied by the misexpression of soma-specific proteins and the initiation of somatic differentiation in germ cells. To investigate whether this is caused by the accumulation of somatic transcripts, we performed mRNA-seq on dissected germlines with and without P granules. Strikingly, we found that somatic transcripts do not increase in the young adult germline when P granules are impaired. Instead, we found that impairing P granules causes sperm-specific mRNAs to become highly overexpressed. This includes the accumulation of major sperm protein (MSP) transcripts in germ cells, a phenotype that is suppressed by feminization of the germline. A core component of P granules, the endo-siRNA-binding Argonaute protein CSR-1, has recently been ascribed with the ability to license transcripts for germline expression. However, impairing CSR-1 has very little effect on the accumulation of its mRNA targets. Instead, we found that CSR-1 functions with P granules to prevent MSP and sperm-specific mRNAs from being transcribed in the hermaphrodite germline. These findings suggest that P granules protect germline integrity through two different mechanisms, by (1) preventing the inappropriate expression of somatic proteins at the level of translational regulation, and by (2) functioning with CSR-1 to limit the domain of sperm-specific expression at the level of transcription.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Células Germinativas/fisiologia , Espermatozoides/metabolismo , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Masculino , Interferência de RNA/fisiologia , Espermatogênese/genética , Espermatogênese/fisiologia
16.
Palliat Med ; 31(2): 162-170, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27170617

RESUMO

BACKGROUND: Enabling patients to die in their preferred place is important but achieving preferred place of death may increase the informal carer's risk into bereavement. AIM: To determine risk factors of family carers bereaved through cancer in Northern Ireland. DESIGN: These results form part of a larger QUALYCARE-NI study which used postal questionnaires to capture quantitative data on carer's bereavement scores using the Texas Revised Inventory of Grief. SETTING/PARTICIPANTS: Participants were individuals who registered the death of a person between 1 December 2011 and 31 May 2012; where cancer (defined by ICD10 codes C00-D48) was the primary cause; where the deceased was over 18 years of age and death occurred at home, hospice, nursing home or hospital in Northern Ireland. Participants were approached in confidence by the Demography and Methodology Branch of the Northern Ireland Statistics and Research Agency. Those wishing to decline participation were invited to return the reply slip. Non-responders received a second questionnaire 6 weeks after initial invitation. Results indicated that risk factors positively influencing bereavement outcomes included patients having no preference for place of death and carers remaining in employment pre- or post-bereavement. In contrast, patients dying in hospital, carers stopping work, being of lower socio-economic status and close kinship to the deceased negatively affected bereavement scores. Family carers should be adequately supported to continue in employment; priority should be given to assessing the financial needs of families from lower socio-economic areas; and bereavement support should focus on close relatives of the deceased.


Assuntos
Luto , Cuidadores/psicologia , Família , Neoplasias/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Emprego/psicologia , Relações Familiares/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Irlanda do Norte , Fatores de Risco , Apoio Social , Fatores Socioeconômicos , Adulto Jovem
17.
Behav Brain Sci ; 40: e82, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-29342540

RESUMO

I identify two confusions and omissions in the target article. Confusion arises from failure to distinguish between a genetically transmitted adaptation and a conditional response to the environment, and from the elision of individual and societal adaptations. Despite points of similarity, there is no mention of Rushton's controversial theory of the climatic basis of race differences in violent crime. Sex differences are also ignored.


Assuntos
Agressão , Autocontrole , Confusão , Feminino , Humanos , Masculino , Caracteres Sexuais , Violência
18.
Br J Nurs ; 26(1): 32-36, 2017 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-28079413

RESUMO

This article explores some of the issues surrounding numerical competence for potential pre-registration children's nursing students, with examples of success and failure, at the University of Hertfordshire. With poor numerical ability causing concern in the UK, and the effect of low competence on patient safety when calculating drug dosages in healthcare, this article considers some of the literature surrounding numerical ability, confidence and anxiety, along with considering whether a 'C' grade at GCSE is a suitable marker for assessing numerical competence before starting a pre-registration nursing programme.


Assuntos
Educação em Enfermagem/normas , Avaliação Educacional , Pesquisa em Educação em Enfermagem , Estudantes de Enfermagem , Humanos
19.
Infect Immun ; 84(9): 2662-70, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27382020

RESUMO

Helicobacter pylori secretes a pore-forming VacA toxin that has structural features and activities substantially different from those of other known bacterial toxins. VacA can assemble into multiple types of water-soluble flower-shaped oligomeric structures, and most VacA activities are dependent on its capacity to oligomerize. The 88-kDa secreted VacA protein can undergo limited proteolysis to yield two domains, designated p33 and p55. The p33 domain is required for membrane channel formation and intracellular toxic activities, and the p55 domain has an important role in mediating VacA binding to cells. Previous studies showed that the p55 domain has a predominantly ß-helical structure, but no structural data are available for the p33 domain. We report here the purification and analysis of a nonoligomerizing mutant form of VacA secreted by H. pylori The nonoligomerizing 88-kDa mutant protein retains the capacity to enter host cells but lacks detectable toxic activity. Analysis of crystals formed by the monomeric protein reveals that the ß-helical structure of the p55 domain extends into the C-terminal portion of p33. Fitting the p88 structural model into an electron microscopy map of hexamers formed by wild-type VacA (predicted to be structurally similar to VacA membrane channels) reveals that p55 and the ß-helical segment of p33 localize to peripheral arms but do not occupy the central region of the hexamers. We propose that the amino-terminal portion of p33 is unstructured when VacA is in a monomeric form and that it undergoes a conformational change during oligomer assembly.


Assuntos
Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Helicobacter pylori/genética , Mutação/genética , Domínios Proteicos/genética , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Linhagem Celular Tumoral , Células HeLa , Helicobacter pylori/metabolismo , Humanos , Canais Iônicos/genética , Canais Iônicos/metabolismo , Microscopia Eletrônica/métodos
20.
Hum Brain Mapp ; 37(11): 3882-3896, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27273695

RESUMO

The frequency of visual gamma oscillations is determined by both the neuronal excitation-inhibition balance and the time constants of GABAergic processes. The gamma peak frequency has been linked to sensory processing, cognitive function, cortical structure, and may have a genetic contribution. To disentangle the intricate relationship among these factors, accurate and reliable estimates of peak frequency are required. Here, a bootstrapping approach that provides estimates of peak frequency reliability, thereby increasing the robustness of the inferences made on this parameter was developed. The method using both simulated data and real data from two previous pharmacological MEG studies of visual gamma with alcohol and tiagabine was validated. In particular, the study by Muthukumaraswamy et al. [] (Neuropsychopharmacology 38(6):1105-1112), in which GABAergic enhancement by tiagabine had previously demonstrated a null effect on visual gamma oscillations, contrasting with strong evidence from both animal models and very recent human studies was re-evaluated. After improved peak frequency estimation and additional exclusion of unreliably measured data, it was found that the GABA reuptake inhibitor tiagabine did produce, as predicted, a marked decrease in visual gamma oscillation frequency. This result demonstrates the potential impact of objective approaches to data quality control, and provides additional translational evidence for the mechanisms of GABAergic transmission generating gamma oscillations in humans. Hum Brain Mapp 37:3882-3896, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Encéfalo/efeitos dos fármacos , Inibidores da Captação de GABA/farmacologia , Ritmo Gama/efeitos dos fármacos , Ácidos Nipecóticos/farmacologia , Percepção Visual/efeitos dos fármacos , Consumo de Bebidas Alcoólicas/metabolismo , Encéfalo/metabolismo , Depressores do Sistema Nervoso Central/farmacologia , Simulação por Computador , Estudos Cross-Over , Etanol/farmacologia , Ritmo Gama/fisiologia , Humanos , Magnetoencefalografia , Modelos Neurológicos , Método Simples-Cego , Tiagabina , Percepção Visual/fisiologia , Ácido gama-Aminobutírico
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