Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 187
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Public Health ; 224: 41-44, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37714065

RESUMO

OBJECTIVE: This paper presents an evidence informed rationale for focussing on harmful gambling products and industry practices in public health messaging through the example of a recent innovation called 'Odds Are: They Win'. METHODS: 'Odds Are: They Win' was initially developed through coproduction involving public health professionals and people with lived experience of gambling harms and implemented across a city-region area. A review of relevant evidence was undertaken, upon which the research team reflected to draw out the implications of 'Odds Are: They Win' for gambling harms messaging. RESULTS: Evidence is mounting that safer gambling campaigns framed in terms of individual responsibility are ineffective and can generate stigma. 'Odds Are: They Win' presents an alternative focus that is not anti-gambling but raises awareness of industry manipulation of the situational and structural context of gambling. This is in-keeping with historical lessons from the stop smoking field and emerging research in critical health literacy. The latter highlights the potential of education on the social and commercial determinants of health to stimulate behaviour change and collective action. CONCLUSION: 'Odds Are: They Win' is a potentially disruptive innovation for the gambling harms field. Research is required to robustly evaluate this intervention across diverse criteria, target audiences, and delivery settings.

2.
Nature ; 525(7568): 226-9, 2015 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-26302297

RESUMO

Metallic osmium (Os) is one of the most exceptional elemental materials, having, at ambient pressure, the highest known density and one of the highest cohesive energies and melting temperatures. It is also very incompressible, but its high-pressure behaviour is not well understood because it has been studied so far only at pressures below 75 gigapascals. Here we report powder X-ray diffraction measurements on Os at multi-megabar pressures using both conventional and double-stage diamond anvil cells, with accurate pressure determination ensured by first obtaining self-consistent equations of state of gold, platinum, and tungsten in static experiments up to 500 gigapascals. These measurements allow us to show that Os retains its hexagonal close-packed structure upon compression to over 770 gigapascals. But although its molar volume monotonically decreases with pressure, the unit cell parameter ratio of Os exhibits anomalies at approximately 150 gigapascals and 440 gigapascals. Dynamical mean-field theory calculations suggest that the former anomaly is a signature of the topological change of the Fermi surface for valence electrons. However, the anomaly at 440 gigapascals might be related to an electronic transition associated with pressure-induced interactions between core electrons. The ability to affect the core electrons under static high-pressure experimental conditions, even for incompressible metals such as Os, opens up opportunities to search for new states of matter under extreme compression.

3.
J Microsc ; 279(3): 177-184, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31823372

RESUMO

For many nanoparticle applications it is important to understand dispersion in liquids. For nanomedicinal and nanotoxicological research this is complicated by the often complex nature of the biological dispersant and ultimately this leads to severe limitations in the analysis of the nanoparticle dispersion by light scattering techniques. Here we present an alternative analysis and associated workflow which utilises electron microscopy. The need to collect large, statistically relevant datasets by imaging vacuum dried, plunge frozen aliquots of suspension was accomplished by developing an automated STEM imaging protocol implemented in an SEM fitted with a transmission detector. Automated analysis of images of agglomerates was achieved by machine learning using two free open-source software tools: CellProfiler and ilastik. The specific results and overall workflow described enable accurate nanoparticle agglomerate analysis of particles suspended in aqueous media containing other potential confounding components such as salts, vitamins and proteins. LAY DESCRIPTION: In order to further advance studies in both nanomedicine and nanotoxicology, we need to continue to understand the dispersion of nanoparticles in biological fluids. These biological environments often contain a number of components such as salts, vitamins and proteins which can lead to difficulties when using traditional techniques to monitor dispersion. Here we present an alternative analysis which utilises electron microscopy. In order to use this approach statistically relevant large image datasets were collected from appropriately prepared samples of nanoparticle suspensions by implementing an automated imaging protocol. Automated analysis of these images was achieved through machine learning using two readily accessible freeware; CellProfiler and ilastik. The workflow presented enables accurate nanoparticle dispersion analysis of particles suspended in more complex biological media.


Assuntos
Automação/métodos , Processamento de Imagem Assistida por Computador/métodos , Aprendizado de Máquina , Microscopia Eletrônica/métodos , Nanopartículas , Fenômenos Biofísicos , Meios de Cultura , Difusão Dinâmica da Luz , Compostos Férricos/química , Software , Água/química , Fluxo de Trabalho
4.
Health Promot Int ; 35(4): 804-811, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31407795

RESUMO

Gender variations in health literacy have implications for engagement in preventive behaviours and the uptake of health services, especially in areas such as the Caribbean where there are marked disparities in life expectancy and health service utilization. A self-reported questionnaire was used to examine men's concepts of health, their help-seeking behaviours and their functional and interactive health literacy. Two hundred and forty-eight men across the life course participated at three sites in Trinidad. Data were analysed using descriptive statistics, with free-text responses analysed thematically. Men were concerned about, and accepted responsibility for their own health but social norms concerning sickness and masculinity were barriers to accessing health services. Almost one-third (31.5%) sought advice from a healthcare service when they were last sick because they were prompted to do so by their wife/partner or family. Levels of functional and interactive health literacy were not high among older men, who were reliant on healthcare professionals to communicate health messages. There was an age divide in e-health literacy. There is little published evidence on men's health literacy, particularly from Caribbean countries such as Trinidad and Tobago. This study highlights the importance of the design and implementation of specific policies focusing on men's health. A major challenge is to engage with men who do not access health services.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Letramento em Saúde/estatística & dados numéricos , Saúde do Homem , Adolescente , Adulto , Idoso , Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , Masculinidade , Pessoa de Meia-Idade , Inquéritos e Questionários , Telemedicina , Trinidad e Tobago
5.
Int Nurs Rev ; 67(2): 294-299, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32367661

RESUMO

AIM: This investigation explored the extent to which nurses' own health is a priority for global National Nursing Associations. BACKGROUND: There is a growing body of evidence linking staff health and well-being and key dimensions of service quality, including patient safety, patient experience and the effectiveness of patient care. INTRODUCTION: The International Council of Nurses is a federation of more than 130 National Nurses Associations, representing more than 20 million nurses worldwide. Representatives from these Associations attended a Congress in Singapore in 2019 at which a survey was conducted. METHODS: A convenience sample of 37 leaders of National Nurse Associations from 33 countries and 61 nurse representatives took part in a survey. RESULTS: The majority of nurse leaders and participants believed that nurses' own health should be a priority to be addressed, principally because a healthy nurse is better able to provide good patient care. All of the examples offered about how these Associations address nurses' own health were about actions to prompt individual health behaviour change. DISCUSSION: The National Nurses Associations did not have a common terminology to talk about nurses' own health. Taking care of one's own health was included as part of the professional role and most nurse leaders thought that working conditions contributed to ill health. CONCLUSIONS: There is widespread agreement that nurses' own health matters but for most National Nurses Associations it is not a current priority. IMPLICATIONS FOR NURSING POLICY: Going forward nurse health and wellbeing should be a core principle for health services and professional associations, and additional research is needed that demonstrates if improving working environments contributes to nurse retention and recruitment.


Assuntos
Nível de Saúde , Cuidados de Enfermagem/estatística & dados numéricos , Recursos Humanos de Enfermagem/estatística & dados numéricos , Sociedades de Enfermagem/estatística & dados numéricos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Singapura , Inquéritos e Questionários
6.
Occup Med (Lond) ; 68(4): 228-238, 2018 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-29579241

RESUMO

Background: There is evidence that the prevalence of overweight and obesity among nurses is increasing. As well as the impact on health, the costs associated with obesity include workplace injury, lost productivity and sickness absence. Finding ways to address obesity in nurses may be a challenge because of the barriers they face in leading a healthy lifestyle. Aims: To identify the available evidence for interventions to address obesity in nurses. Methods: Databases searched included CINAHL, SCOPUS (which encompasses the Cochrane Database of Systematic Reviews), PsycINFO, MEDLINE and British Nursing Index. Ancillary searching of the grey literature was conducted for case studies of weight management interventions in National Health Service (NHS) settings. Inclusion criteria were studies involving nurses that reported on interventions addressing health behaviours that contribute to obesity and included at least one obesity-related outcome measure. Results: Eleven primary studies were found concerning lifestyle interventions for nurses. There was no strong evidence for any particular intervention to address obesity, although integrating interventions into nurses' daily working lives may be important. Case studies from the grey literature showcased a range of interventions, but very few studies reported outcomes. Conclusions: The review demonstrates that there is insufficient good-quality evidence about successful interventions to address obesity in nurses. Evidence does indicate that interventions should be designed around the specific barriers nurses may face in leading a healthy lifestyle.


Assuntos
Promoção da Saúde/normas , Enfermeiras e Enfermeiros/psicologia , Obesidade/prevenção & controle , Obesidade/terapia , Exercício Físico/psicologia , Promoção da Saúde/métodos , Humanos , Enfermeiras e Enfermeiros/tendências , Prevalência
7.
Mutagenesis ; 29(3): 165-75, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24675152

RESUMO

Recent restrictions on the testing of cosmetic ingredients in animals have resulted in the need to test the genotoxic potential of chemicals exclusively in vitro prior to licensing. However, as current in vitro tests produce some misleading positive results, sole reliance on such tests could prevent some chemicals with safe or beneficial exposure levels from being marketed. The 3D human reconstructed skin micronucleus (RSMN) assay is a promising new in vitro approach designed to assess genotoxicity of dermally applied compounds. The assay utilises a highly differentiated in vitro model of the human epidermis. For the first time, we have applied automated micronucleus detection to this assay using MetaSystems Metafer Slide Scanning Platform (Metafer), demonstrating concordance with manual scoring. The RSMN assay's fixation protocol was found to be compatible with the Metafer, providing a considerably shorter alternative to the recommended Metafer protocol. Lowest observed genotoxic effect levels (LOGELs) were observed for mitomycin-C at 4.8 µg/ml and methyl methanesulfonate (MMS) at 1750 µg/ml when applied topically to the skin surface. In-medium dosing with MMS produced a LOGEL of 20 µg/ml, which was very similar to the topical LOGEL when considering the total mass of MMS added. Comparisons between 3D medium and 2D LOGELs resulted in a 7-fold difference in total mass of MMS applied to each system, suggesting a protective function of the 3D microarchitecture. Interestingly, hydrogen peroxide (H2O2), a positive clastogen in 2D systems, tested negative in this assay. A non-genotoxic carcinogen, methyl carbamate, produced negative results, as expected. We also demonstrated expression of the DNA repair protein N-methylpurine-DNA glycosylase in EpiDerm™. Our preliminary validation here demonstrates that the RSMN assay may be a valuable follow-up to the current in vitro test battery, and together with its automation, could contribute to minimising unnecessary in vivo tests by reducing in vitro misleading positives.


Assuntos
Testes para Micronúcleos/métodos , Pele/efeitos dos fármacos , Pele/patologia , Automação , Carbamatos/toxicidade , Linhagem Celular , DNA Glicosilases/genética , Relação Dose-Resposta a Droga , Expressão Gênica/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/toxicidade , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Queratinócitos/patologia , Metanossulfonato de Metila/toxicidade , Testes para Micronúcleos/estatística & dados numéricos , Mitomicina/toxicidade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reprodutibilidade dos Testes , Pele/metabolismo , Técnicas de Cultura de Tecidos/métodos
8.
J Biomech ; 152: 111587, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37080081

RESUMO

Markerless motion capture has improved physical screening efficiency in sport and occupational settings; however, reliability of kinematic measurements from commercial systems must be established. Further, the impact of torso-borne equipment on these measurements is unclear. The purpose of this study was to evaluate the reliability of HumanTrak, a markerless motion capture system, for estimating peak trunk flexion in squat movements with and without a weighted vest. Eighteen participants completed body weight squats (BWSQ) and overhead squats (OHSQ) to their maximum depth (unrestricted-range) and to a plyometric box (fixed-range) while wearing no body armour (NBA) or 9 kg body armour (BA9). Peak trunk flexion was measured using HumanTrak. Testing was performed in two sessions on one day (intra-day) and one session on a separate day (inter-day) to assess reliability. HumanTrak had a standard error of measurement < 3.74° across all movements and conditions. Reliability was good to excellent (ICC = 0.82-0.96) with very large to nearly perfect Pearson correlations (r > 0.80) for all comparisons except unrestricted-range BWSQ with BA9 (ICC = 0.60-0.71, r = 0.71). HumanTrak was more reliable for intra- than inter-day, but reliability was still excellent for almost all inter-day comparisons (ICC > 0.82). HumanTrak is reliable for detecting differences in peak trunk flexion > 8.5° when body armour is not worn and > 10.5° when body armour is worn. Practitioners can assess meaningful changes in sagittal plane trunk motion when screening squat movements regardless of whether body armour is worn.


Assuntos
Captura de Movimento , Postura , Humanos , Reprodutibilidade dos Testes , Movimento , Amplitude de Movimento Articular , Fenômenos Biomecânicos
9.
Occup Med (Lond) ; 62(1): 17-22, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21949012

RESUMO

BACKGROUND: Environmental health practice in the field of occupational health and safety is traditionally concerned with protecting health relating to the workplace. However, little is currently known about environmental health officers' (EHOs) perceptions of their role in workplace health improvement, a pertinent topic in light of the recent government agenda for improving the health of the workforce in the UK. AIMS: To explore how EHOs perceive workplace health improvement and its relevance to their professional role. METHODS: A qualitative methodology was employed, using a case-study design with thematic analysis of 15 transcripts of in-depth telephone interviews with EHOs working in London, UK. RESULTS: EHOs view themselves primarily as enforcement officers, with legislation guiding their understandings of workplace health. Many interpret work-related ill health in terms of safety and physical injury and do not feel competent in assessing broader psychosocial elements of ill health. However, a few EHOs welcomed the opportunity to promote health in the workplace, recognizing the importance of prevention. CONCLUSIONS: This study indicates a gap between the contemporary EHO role framed by professional bodies as holistic and contributing to public health goals and the role perceived by EHOs 'on the ground'. A more traditional, protective and enforcement-based approach persists among EHOs in this sample, and few feel they have skills to address determinants beyond physical hazards to health. Yet, a minority of EHOs adopted a more health-promoting approach, suggesting that the potential contribution of EHOs to the workplace health improvement agenda should be explored further.


Assuntos
Saúde Ambiental , Saúde Ocupacional , Papel Profissional , Promoção da Saúde , Humanos , Londres , Pesquisa Qualitativa , Recursos Humanos , Local de Trabalho
10.
J Small Anim Pract ; 63(11): 809-815, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35986507

RESUMO

OBJECTIVES: Diabetes mellitus is a common condition that requires intensive treatment and markedly impacts the welfare of affected cats. The aim of this study was to identify diabetes mellitus-associated perturbations in the feline pancreatic islet microenvironment. The utility of "clear, unobstructed brain/body imaging cocktails and computational analysis" (CUBIC) for three-dimensional pancreatic analysis was investigated. METHODS: Formalin-fixed paraffin-embedded tissues from cats with diabetes mellitus, or control cats without pancreatic pathology, were retrospectively identified. Immunohistochemistry for synaptophysin and ionised calcium binding adaptor molecule 1, and immunofluorescence for insulin and synaptophysin, were used to assess changes in islets. An image analysis pipeline was developed to analyse images acquired from two-dimensional immunofluorescence. CUBIC was used to optically clear selected pancreas samples before immunofluorescence and deep three-dimensional confocal microscopy. RESULTS: Diabetic cats have a significant reduction in synaptophysin-positive islet area. Whilst islets from diabetic patients have similar numbers of ß cells to islets from control cats, significantly lower intensity of insulin expression can be observed in the former. CUBIC facilitates clear visualisation of pancreatic islets in three dimensions. CLINICAL SIGNIFICANCE: The data presented support the theory that there is a decrease in function of ß cells before their destruction, suggesting a potentially significant step in the pathogenesis of feline diabetes mellitus. In parallel, we demonstrate CUBIC as a valuable new tool to visualise the shape of feline pancreatic islets and to interrogate pathology occurring in the islets of diabetic pets.


Assuntos
Doenças do Gato , Diabetes Mellitus , Ilhotas Pancreáticas , Gatos , Animais , Insulina , Sinaptofisina/metabolismo , Estudos Retrospectivos , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Diabetes Mellitus/veterinária , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patologia , Doenças do Gato/patologia
11.
Front Endocrinol (Lausanne) ; 13: 989523, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36329893

RESUMO

Objective: Obesity increases the risk of certain cancers, especially tumours that reside close to adipose tissue (breast and ovarian metastasis in the omentum). The obesogenic and tumour micro-environment share a common pathogenic feature, oxygen deprivation (hypoxia). Here we test how hypoxia changes the metabolome of adipocytes to assist cancer cell growth. Methods: Human and mouse breast and ovarian cancer cell lines were co-cultured with human and mouse adipocytes respectively under normoxia or hypoxia. Proliferation and lipid uptake in cancer cells were measured by commercial assays. Metabolite changes under normoxia or hypoxia were measured in the media of human adipocytes by targeted LC/MS. Results: Hypoxic cancer-conditioned media increased lipolysis in both human and mouse adipocytes. This led to increased transfer of lipids to cancer cells and consequent increased proliferation under hypoxia. These effects were dependent on HIF1α expression in adipocytes, as mouse adipocytes lacking HIF1α showed blunted responses under hypoxic conditions. Targeted metabolomics of the human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes media revealed that culture with hypoxic-conditioned media from non-malignant mammary epithelial cells (MCF10A) can alter the adipocyte metabolome and drive proliferation of the non-malignant cells. Conclusion: Here, we show that hypoxia in the adipose-tumour microenvironment is the driving force of the lipid uptake in both mammary and ovarian cancer cells. Hypoxia can modify the adipocyte metabolome towards accelerated lipolysis, glucose deprivation and reduced ketosis. These metabolic shifts in adipocytes could assist both mammary epithelial and cancer cells to bypass the inhibitory effects of hypoxia on proliferation and thrive.


Assuntos
Adipócitos , Neoplasias Ovarianas , Humanos , Camundongos , Animais , Feminino , Meios de Cultivo Condicionados/farmacologia , Meios de Cultivo Condicionados/metabolismo , Adipócitos/metabolismo , Hipóxia/metabolismo , Hipóxia/patologia , Proliferação de Células , Lipídeos/farmacologia , Neoplasias Ovarianas/metabolismo , Microambiente Tumoral
12.
Eur J Vasc Endovasc Surg ; 40(2): 191-5, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20537568

RESUMO

BACKGROUND: The nature of the inflammatory change within ruptured AAA has not been extensively reported. The aim of this study was to compare the inflammatory response in non-ruptured and ruptured aneurysms with emphasis on the site of rupture. METHODS: Non-rupture site biopsies were taken from the anterior aneurysm sac of non-ruptured (n=31) and ruptured AAA (n=20). In 12 ruptured AAA, a further biopsy was taken from the rupture site. Enzyme-linked immunosorbent assay was used to quantify IL-6, IL-1beta and TNF-alpha. Quantitative immunohistochemistry was undertaken for generic lymphocytes, T-cells, and B-cells. RESULTS: Comparing biopsies in non-ruptured AAA versus a non-rupture site biopsy from ruptured AAA; there was no significant difference in IL-6, IL-1beta, TNF-alpha, generic lymphocytes, T-cell or B-cell content. Comparing ruptured AAA--non-rupture site with rupture site; IL-6 and TNF-alpha were unchanged. By contrast IL-1beta and lymphocytes were lower at the rupture site compared to the non-rupture site (IL-1beta 1.39 ng/mg [0.97-2.29] vs. 1.92 ng/mg [1.46-2.57], p=0.027; generic lymphocytes 2.89% [0.51-5.51] vs. 4.73% [2.27-12.40], p=0.018; T-cells 0.28% [0.04-1.18] vs. 0.82% [0.40-1.36], p=0.027; B-cells 0.16% [0.04-1.14] vs. 1.30% [0.32-5.40], p=0.021). CONCLUSIONS: These findings suggest the biological events leading to AAA rupture may not be dependent on an up-regulation in the inflammatory process.


Assuntos
Aneurisma Roto/metabolismo , Aneurisma da Aorta Abdominal/metabolismo , Regulação para Cima/fisiologia , Aneurisma Roto/diagnóstico por imagem , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Ensaio de Imunoadsorção Enzimática , Humanos , Imidazóis/metabolismo , Imuno-Histoquímica , Mediadores da Inflamação/metabolismo , Interleucina-1beta/metabolismo , Contagem de Linfócitos , Quinolonas/metabolismo , Radiografia , Fator de Necrose Tumoral alfa/metabolismo
13.
J Cell Biol ; 99(6): 2011-23, 1984 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-6094591

RESUMO

The envelope glycoproteins of Rous sarcoma virus (RSV), gp85 and gp37, are anchored in the membrane by a 27-amino acid, hydrophobic domain that lies adjacent to a 22-amino acid, cytoplasmic domain at the carboxy terminus of gp37. We have altered these cytoplasmic and transmembrane domains by introducing deletion mutations into the molecularly cloned sequences of a proviral env gene. The effects of the mutations on the transport and subcellular localization of the Rous sarcoma virus glycoproteins were examined in monkey (CV-1) cells using an SV40 expression vector. We found, on the one hand, that replacement of the nonconserved region of the cytoplasmic domain with a longer, unrelated sequence of amino acids (mutant C1) did not alter the rate of transport to the Golgi apparatus nor the appearance of the glycoprotein on the cell surface. Larger deletions, extending into the conserved region of the cytoplasmic domain (mutant C2), resulted in a slower rate of transport to the Golgi apparatus, but did not prevent transport to the cell surface. On the other hand, removal of the entire cytoplasmic and transmembrane domains (mutant C3) did block transport and therefore did not result in secretion of the truncated protein. Our results demonstrate that the C3 polypeptide was not transported to the Golgi apparatus, although it apparently remained in a soluble, nonanchored form in the lumen of the rough endoplasmic reticulum; therefore, it appears that this mutant protein lacks a functional sorting signal. Surprisingly, subcellular localization by internal immunofluorescence revealed that the C3 protein (unlike the wild type) did not accumulate on the nuclear membrane but rather in vesicles distributed throughout the cytoplasm. This observation suggests that the wild-type glycoproteins (and perhaps other membrane-bound or secreted proteins) are specifically transported to the nuclear membrane after their biosynthesis elsewhere in the rough endoplasmic reticulum.


Assuntos
Vírus do Sarcoma Aviário/genética , Genes Virais , Genes , Glicoproteínas/genética , Mutação , Proteínas do Envelope Viral/análise , Proteínas do Envelope Viral/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Chlorocebus aethiops , Enzimas de Restrição do DNA , Escherichia coli/genética , Glicoproteínas/análise , Rim , Plasmídeos , Frações Subcelulares/metabolismo
14.
J Cell Biol ; 103(3): 829-38, 1986 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3017996

RESUMO

Protein sequence requirements for cleavage of the signal peptide from the Rous sarcoma virus glycoprotein have been investigated through the use of deletion mutagenesis. The phenotypes of these mutants have been characterized by expression of the cloned, mutated env genes in CV-1 cells using a late replacement SV40 vector. The deletion mutations were generated by Ba131 digestion at the XhoI site located near the 5' end of the coding sequence for the structural protein gp85, which is found at the amino terminus of the precursor glycoprotein, Pr95. The results of experiments with three mutants (X1, X2, and X3) are presented. Mutant X1 has a 14 amino acid deletion encompassing amino acids 4-17 of gp85, which results in the loss of one potential glycosylation site. In mutants X2 and X3 the amino terminal nine and six amino acids, respectively, of gp85 are deleted. During the biosynthesis of all three mutant polypeptides, the signal peptide is efficiently and accurately cleaved from the nascent protein, even though in mutants X2 and X3 the cleavage site itself has been altered. In these mutants the alanine/aspartic acid cleavage site has been mutated to alanine/asparagine and alanine/glutamine, respectively. These results are consistent with the concept that sequences C-terminal to the signal peptidase site are unimportant in defining the site of cleavage in eucaryotes. Mutants X2 and X3 behave like wild-type with respect to protein glycosylation, palmitic acid addition, cleavage to gp85 and gp37, and expression on the cell surface. Mutant X1, on the other hand, is defective in intracellular transport. Although it is translocated across the rough endoplasmic reticulum and core-glycosylated, its transport appears to be blocked at an early Golgi compartment. No terminal glycosylation of the protein, cleavage of the precursor protein to the mature products, or expression on the cell surface is observed. The deletion in X1 thus appears to destroy signals required for export to the cell surface.


Assuntos
Vírus do Sarcoma Aviário/genética , Sinais Direcionadores de Proteínas/metabolismo , Proteínas do Envelope Viral/metabolismo , Sequência de Aminoácidos , Animais , Transporte Biológico , Linhagem Celular , Chlorocebus aethiops , Fibroblastos/ultraestrutura , Imunofluorescência , Rim , Precursores de Proteínas/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas do Envelope Viral/genética
15.
Rev Sci Instrum ; 79(4): 043304, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18447525

RESUMO

Ion beam extraction from two different ion sources with single aperture triode extraction columns was simulated with the particle beam transport codes PBGUNS and IGUN. For each ion source, the simulation results are compared to experimental data generated on well-equipped test stands. Both codes reproduced the qualitative behavior of the extracted ion beams to incremental and scaled changes to the extraction electrode geometry observed on the test stands. Numerical values of optimum beam currents and beam emittance generated by the simulations also agree well with test stand data.

16.
Mol Cell Biol ; 2(7): 853-62, 1982 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6765567

RESUMO

Candida albicans is a dimorphic fungus that is pathogenic for humans. No sexual cycle has been reported for this fungus, and earlier reports have differed on whether typical strains of C. albicans are haploid or diploid. Previous estimates of the DNA content of C. albicans varied by one order of magnitude. We used three independent methods to measure the kinetic complexity of the single-copy DNA from a typical strain of C. albicans (strain H317) to determine the DNA content per haploid genote; we obtained values of 15 and 20 fg per cell by using S1 nuclease and hydroxyapatite assays, respectively. Optical assays for DNA reassociation kinetics, although not definitive in themselves, yielded values in this range. Chemical measurements of the DNA content of several typical strains, including strain H317, yielded values clustered about a mean of 37 fg per cell. We concluded that these strains are diploid.


Assuntos
Candida albicans/genética , DNA Fúngico/genética , Cinética , Renaturação de Ácido Nucleico , Ploidias
17.
J Mol Biol ; 279(4): 921-8, 1998 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-9642071

RESUMO

A biologically active construct of the retroviral M domain from the avian Rous sarcoma virus is defined and its solution structure described. This M domain is fully active in budding and infectivity without myristylation. In spite of a sequence homology level that suggests no relationship among M domains and the family of matrix proteins in mammalian retroviruses, the conserved structural elements of a central core allow an M domain sequence motif to be described for all retroviruses. The surface of the M domain has a highly clustered positive patch comprised of sequentially distant residues. An analysis of the backbone dynamics, incorporating rotational anisotropy, is used to estimate the thermodynamics of proposed domain oligomerization.


Assuntos
Vírus do Sarcoma Aviário/química , Proteínas dos Retroviridae/química , Proteínas da Matriz Viral/química , Sequência de Aminoácidos , Dados de Sequência Molecular , Conformação Proteica , Proteínas dos Retroviridae/genética , Alinhamento de Sequência , Análise de Sequência , Relação Estrutura-Atividade , Proteínas da Matriz Viral/genética
18.
Eur J Clin Nutr ; 69(5): 619-25, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25351645

RESUMO

BACKGROUND/OBJECTIVES: The research question addressed in this paper is how different reference amounts utilised in front of package nutrition labelling influence evaluation of product healthfulness. SUBJECTS/METHODS: A total of 13,117 participants from six European countries (Germany, UK, Spain, France, Poland and Sweden) were recruited via online panels. A mixed between/within-subject factorial design was employed with food (biscuits, sandwiches, yogurts), healthfulness and presence of Guideline Daily Amounts as within-subjects factors and reference amount ('per 100 g', 'typical portion', 'half portion') and country as between-subjects factors. RESULTS: Overall, people correctly ranked foods according to their objective healthfulness as defined by risk nutrients alone, and could distinguish between more and less healthful variants of foods. General healthfulness associations with the three product categories do not appear to have had a strong influence on product ratings. This study shows that where the reference amount of 'per 100 g' is very different from the 'typical' portion size, as was the case for biscuits, products with a 'per 100 g' label are rated significantly less healthful than the 'typical' or 'half typical' portions. CONCLUSION: The results indicate that across the three food categories, consumers do factor the reference amount, that is, the quantity of food for which the nutritional information is being presented, into their judgements of healthfulness. Therefore, appropriate reference amounts are also of importance for the effective presentation of nutritional information.


Assuntos
Comportamento de Escolha , Rotulagem de Alimentos/métodos , Preferências Alimentares , Alimentos , Comportamentos Relacionados com a Saúde , Valor Nutritivo , Adulto , Comportamento do Consumidor , Europa (Continente) , Feminino , Humanos , Masculino , Política Nutricional
19.
Nutr Bull ; 40(1): 66-72, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25750587

RESUMO

Health claims and symbols are potential aids to help consumers identify foods that are healthier options. However, little is known as to how health claims and symbols are used by consumers in real-world shopping situations, thus making the science-based formulation of new labelling policies and the evaluation of existing ones difficult. The objective of the European Union-funded project Role of health-related CLaims and sYMBOLs in consumer behaviour (CLYMBOL) is to determine how health-related information provided through claims and symbols, in their context, can affect consumer understanding, purchase and consumption. To do this, a wide range of qualitative and quantitative consumer research methods are being used, including product sampling, sorting studies (i.e. how consumers categorise claims and symbols according to concepts such as familiarity and relevance), cross-country surveys, eye-tracking (i.e. what consumers look at and for how long), laboratory and in-store experiments, structured interviews, as well as analysis of population panel data. EU Member States differ with regard to their history of use and regulation of health claims and symbols prior to the harmonisation of 2006. Findings to date indicate the need for more structured and harmonised research on the effects of health claims and symbols on consumer behaviour, particularly taking into account country-wide differences and individual characteristics such as motivation and ability to process health-related information. Based on the studies within CLYMBOL, implications and recommendations for stakeholders such as policymakers will be provided.

20.
Cell Death Differ ; 22(5): 838-51, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25394490

RESUMO

Aberrant posttranslational modifications (PTMs) of proteins, namely phosphorylation, induce abnormalities in the biological properties of recipient proteins, underlying neurological diseases including Parkinson's disease (PD). Genome-wide studies link genes encoding α-synuclein (α-Syn) and Tau as two of the most important in the genesis of PD. Although several kinases are known to phosphorylate α-Syn and Tau, we focused our analysis on GSK-3ß because of its accepted role in phosphorylating Tau and to increasing evidence supporting a strong biophysical relationship between α-Syn and Tau in PD. Therefore, we investigated transgenic mice, which express a point mutant (S9A) of human GSK-3ß. GSK-3ß-S9A is capable of activation through endogenous natural signaling events, yet is unable to become inactivated through phosphorylation at serine-9. We used behavioral, biochemical, and in vitro analysis to assess the contributions of GSK-3ß to both α-Syn and Tau phosphorylation. Behavioral studies revealed progressive age-dependent impairment of motor function, accompanied by loss of tyrosine hydroxylase-positive (TH+ DA-neurons) neurons and dopamine production in the oldest age group. Magnetic resonance imaging revealed deterioration of the substantia nigra in aged mice, a characteristic feature of PD patients. At the molecular level, kinase-active p-GSK-3ß-Y216 was seen at all ages throughout the brain, yet elevated levels of p-α-Syn-S129 and p-Tau (S396/404) were found to increase with age exclusively in TH+ DA-neurons of the midbrain. p-GSK-3ß-Y216 colocalized with p-Tau and p-α-Syn-S129. In vitro kinase assays showed that recombinant human GSK-3ß directly phosphorylated α-Syn at a single site, Ser129, in addition to its known ability to phosphorylate Tau. Moreover, α-Syn and Tau together cooperated with one another to increase the magnitude or rate of phosphorylation of the other by GSK-3ß. Together, these data establish a novel upstream role for GSK-3ß as one of several kinases associated with PTMs of key proteins known to be causal in PD.


Assuntos
Quinase 3 da Glicogênio Sintase/metabolismo , Transtornos Parkinsonianos/metabolismo , Transtornos Parkinsonianos/fisiopatologia , alfa-Sinucleína/metabolismo , Proteínas tau/metabolismo , Animais , Quinase 3 da Glicogênio Sintase/genética , Glicogênio Sintase Quinase 3 beta , Humanos , Camundongos , Camundongos Transgênicos , Transtornos Parkinsonianos/genética , Transtornos Parkinsonianos/patologia , alfa-Sinucleína/genética , Proteínas tau/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA