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1.
BMC Geriatr ; 23(1): 125, 2023 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-36879201

RESUMO

BACKGROUND: Low physical activity in care home residents brings about negative mental health consequences, such as higher levels of depression and loneliness. With advancements in communication technology, particularly during the COVID-19 pandemic, the feasibility and effectiveness of a randomised controlled trial (RCT) of a digital Physical Activity (PA) resource in care homes deserve more research attention. A realist evaluation was used to uncover influencing factors of a feasibility study implementation to inform how a digital music and movement programme would work and under what circumstances this would be most effective. METHODS: Participants were 49 older adults (aged 65 years +) recruited across ten care homes in Scotland. Surveys were administered at baseline and post-intervention comprising psychometric questionnaires on multidimensional health markers validated in older adults with possible cognitive impairment. The intervention comprised 12 weeks of four prescribed digitally delivered movement (n = 3) and music-only (n = 1) sessions per week. An activity coordinator delivered these online resources in the care home. Post-intervention focus groups with staff and interviews with a sub-sample of participants were conducted to gain qualitative data on the acceptability of the intervention. RESULTS: Thirty three care home residents started the intervention, but only 18 residents (84% female) completed both pre- and post-intervention assessments. Activity coordinators (AC) offered 57% of the prescribed sessions, with an average residents' adherence of 60%. Delivery of the intervention did not go as planned due to Covid restrictions in care homes and delivery challenges, including (1) motivation and engagement, (2) changes in cognitive impairment and disabilities of the participants, (3) death or hospitalisation of the participants and (4) limited staffing and technology resources to deliver the programme as intended. Despite this, group participation and encouragement of residents supported the delivery and acceptance of the intervention, with ACs and residents reporting improved mood, physical health, job satisfaction and social support. Improvements with large effect sizes were found for anxiety, depression, loneliness, perceived stress and sleep satisfaction, but no changes in fear of falling, domains of general health or appetite. CONCLUSION: This realist evaluation suggested that this digitally delivered movement and music intervention is feasible. From the findings, the initial programme theory was refined for future implementation of an RCT in other care homes but future research exploring how to tailor the intervention to those with cognitive impairment and/or lacking capacity to consent is needed. TRIAL REGISTRATION: Retrospectively registered at ClinicalTrials.gov NCT05559203.


Assuntos
COVID-19 , Música , Feminino , Humanos , Idoso , Masculino , COVID-19/epidemiologia , Estudos de Viabilidade , Acidentes por Quedas , Ansiedade
2.
Meteorit Planet Sci ; 55(8): 1808-1832, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34376965

RESUMO

Constraining the duration of magmatic activity on the Moon is essential to understand how the lunar mantle evolved chemically through time. Determining age and initial isotopic compositions of mafic lunar meteorites is a critical step in defining the periods of magmatic activity that occurred during the history of the Moon and to constrain the chemical characteristics of mantle components involved in the sources of the magmas. We have used the in situ Pb-Pb SIMS technique to investigate eight lunar gabbros and basalts, including six meteorites from the Northwest Africa (NWA) 773 clan (NWA 2727, NWA 2700, NWA 3333, NWA 2977, NWA 773, and NWA 3170), NWA 4734, and Dhofar 287A. These samples have been selected as there is no clear agreement on their age and they are all from the dominant low titanium chemical group. We have obtained ages of 2981 ± 12 Ma for NWA 4734 and 3208 ± 22 Ma for Dhofar 287. For the NWA 773 clan, four samples (the fine-grained basalt NWA 2727 and the three gabbros NWA 773, NWA 2977, NWA 3170) out of six yielded isochron-calculated ages that are identical within uncertainties and yielding an average age of 3086 ± 5 Ma. The age obtained for the fine-grained basalt NWA 2700 is not precise enough for comparison with the other samples. The gabbroic sample NWA 3333 yielded an age of 3038 ± 20 Ma suggesting that two distinct magmatic events may be recorded in the meteorites of the NWA 773 clan. The present study aims to identify and assess all potential issues that are associated with different ways to date lunar rocks using U-Pb-based methods. To achieve this, we have compared the new ages with the previously published data set. The entire age data set from lunar mafic meteorites was also screened to identify data showing analytical issues and evidence of resetting and terrestrial contamination. The data set combining the ages of mafic lunar meteorites and Apollo rocks suggests pulses of magmatic activity with two distinct phases between 3950 and 3575 Ma and between 3375 and 3075 Ma with the two phases separated by a gap of approximately 200 Ma. The evolution of the Pb initial ratios of the low-Ti mare basalts between approximately 3400 and 3100 Ma suggests that these rocks were progressively contaminated by a KREEP-like component.

3.
Br J Dermatol ; 179(2): 381-393, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29266210

RESUMO

BACKGROUND: While several commercial dermoepidermal scaffolds can promote wound healing of the skin, the achievement of complete skin regeneration still represents a major challenge. OBJECTIVES: To perform biological characterization of self-assembled extracellular matrices (ECMs) from three different subpopulations of fibroblasts found in human skin: papillary fibroblasts (Pfi), reticular fibroblasts (Rfi) and dermal papilla fibroblasts (DPfi). METHODS: Fibroblast subpopulations were cultured with ascorbic acid to promote cell-assembled matrix production for 10 days. Subsequently, cells were removed and the remaining matrices characterized. Additionally, in another experiment, keratinocytes were seeded on the top of cell-depleted ECMs to generate epidermal-only skin constructs. RESULTS: We found that the ECM self-assembled by Pfi exhibited randomly oriented fibres associated with the highest interfibrillar space, reflecting ECM characteristics that are physiologically present within the papillary dermis. Mass spectrometry followed by validation with immunofluorescence analysis showed that thrombospondin 1 is preferentially expressed within the DPfi-derived matrix. Moreover, we observed that epidermal constructs grown on DPfi or Pfi matrices exhibited normal basement membrane formation, whereas Rfi matrices were unable to support membrane formation. CONCLUSIONS: We argue that inspiration can be taken from these different ECMs, to improve the design of therapeutic biomaterials in skin engineering applications.


Assuntos
Derme/metabolismo , Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Pele Artificial , Alicerces Teciduais , Células Cultivadas , Derme/citologia , Voluntários Saudáveis , Humanos , Cultura Primária de Células/métodos , Couro Cabeludo , Engenharia Tecidual/métodos
4.
Arch Womens Ment Health ; 19(2): 219-27, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26202722

RESUMO

We investigated associations between aspects of childbirth and elevated postpartum symptoms of depression and anxiety. We employed secondary analysis of perinatal data (N = 4657-4946) from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Multivariable logistic regression models (adjusted for covariates) examined predictors of elevated symptoms of postpartum depression and anxiety. Predictors included the following: type of delivery (normal physiological vs. interventive non-physiological), immediate postpartum complications, and maternal perception of the recent birth experience. The Edinburgh Postnatal Depression Scale assessed elevated symptoms of depression (score ≥ 13), and the Crown-Crisp Experiential Index assessed elevated symptoms of anxiety (score ≥ 9) at 2 and 8 months after delivery. A more negative perception of the recent birth experience was associated with elevated symptoms of anxiety at 2 months [odds ratio (OR) 1.52, 95 % confidence interval (CI) 1.25-1.85] and 8 months (OR 1.30, 95 % CI 1.06-1.60) postpartum but was not associated with elevated symptoms of depression at either time point. Type of delivery (physiological vs. non-physiological) and immediate postpartum complications were not associated with elevated symptoms of depression or anxiety. Our findings suggest that improving women's childbirth experience may decrease the likelihood of postpartum anxiety, but not postpartum depression.


Assuntos
Ansiedade/diagnóstico , Parto Obstétrico/psicologia , Depressão Pós-Parto/diagnóstico , Parto/psicologia , Complicações na Gravidez/psicologia , Adolescente , Adulto , Ansiedade/epidemiologia , Criança , Parto Obstétrico/métodos , Depressão Pós-Parto/epidemiologia , Feminino , Humanos , Modelos Logísticos , Período Pós-Parto , Gravidez , Complicações na Gravidez/epidemiologia , Prevalência , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Fatores de Risco , Inquéritos e Questionários , Reino Unido/epidemiologia
5.
Brain Struct Funct ; 229(7): 1737-1756, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39042140

RESUMO

Oxytocin (OXT) is a peptide hormone and a neuropeptide that regulates various peripheral physiological processes and modulates behavioral responses in the central nervous system. While the humoral release occurs from the axons arriving at the median eminence, the neuropeptide is also released from oxytocinergic cell axons in various brain structures that contain its receptor, and from their dendrites in hypothalamic nuclei and potentially into the cerebrospinal fluid (CSF). Understanding oxytocin's complex functions requires the knowledge on patterns of oxytocinergic projections in relationship to its receptor (OXTR). This study provides the first comprehensive examination of the oxytocinergic system in the prairie vole (Microtus ochrogaster), an animal exhibiting social behaviors that mirror human social behaviors linked to oxytocinergic functioning. Using light and electron microscopy, we characterized the neuroanatomy of the oxytocinergic system in this species. OXT+ cell bodies were found primarily in the hypothalamus, and axons were densest in subcortical regions. Examination of the OXT+ fibers and their relationship to oxytocin receptor transcripts (Oxtr) revealed that except for some subcortical structures, the presence of axons was not correlated with the amount of Oxtr across the brain. Of particular interest, the cerebral cortex that had high expression of Oxtr transcripts contained little to no fibers. Electron microscopy is used to quantify dense cored vesicles (DCV) in OXT+ axons and to identify potential axonal release sites. The ependymal cells that line the ventricles were frequently permissive of DCV-containing OXT+ dendrites reaching the third ventricle. Our results highlight a mechanism in which oxytocin is released directly into the ventricles and circulates throughout the ventricular system, may serve as the primary source for oxytocin that binds to OXTR in the cerebral cortex.


Assuntos
Arvicolinae , Ocitocina , Receptores de Ocitocina , Animais , Ocitocina/metabolismo , Receptores de Ocitocina/metabolismo , Masculino , Feminino , Encéfalo/metabolismo , Axônios/metabolismo , Axônios/ultraestrutura , Hipotálamo/metabolismo
6.
Diabet Med ; 30(12): 1420-32, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23870009

RESUMO

INTRODUCTION: With increasing evidence available on the importance of physical activity in the management of Type 2 diabetes, there has been an increase in technology-based interventions. This review provides a systematic and descriptive assessment of the effectiveness of technology to promote physical activity in people with Type 2 diabetes. For this review, technology included mobile phones and text messages, websites, CD-ROMs and computer-learning-based technology, and excluded telephone calls. METHODS: A systematic literature search was conducted to retrieve articles from January 2001 to March 2013 using the following databases: the Cochrane Library, EMBASE, MEDLINE, PsycINFO and PubMed. Articles had to describe an intervention that used technology to promote physical activity in people with Type 2 diabetes. A methodological quality assessment of the studies was conducted and data synthesis was performed. RESULTS: In total, 15 articles were eligible for review: web-based (9), mobile phone (3), CD-ROM (2) and computer based (1). All studies found an increase in physical activity but only nine were significant. The use of a personal coach, logbooks and reinforcement strategies such as phone calls and email counselling were found to be effective components for behaviour change. No studies were ranked as low in terms of methodological quality. CONCLUSIONS: Technology-based interventions to promote physical activity are effective; using further methods to promote participant adherence is associated with greater benefit. Further research should look into strategies to enhance adherence and sustainability in order to increase the effectiveness of technology-based physical activity intervention in diabetes care.


Assuntos
Telefone Celular , Diabetes Mellitus Tipo 2/terapia , Exercício Físico , Promoção da Saúde/métodos , Internet , Envio de Mensagens de Texto , Feminino , Humanos , Masculino , Cooperação do Paciente/estatística & dados numéricos , Satisfação do Paciente/estatística & dados numéricos , Aptidão Física , Sistemas de Alerta , Autocuidado
7.
Caries Res ; 46(5): 467-73, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22796661

RESUMO

Scarce information exists on the clinical features of dental caries in the Imperial Roman population and no structural data on caries lesions from this period have so far been published. We report on the findings of 86 teeth (50-100 AD) found during archaeological excavations of the temple of Castor and Pollux in the Forum Romanum. We found that nearly all teeth had large carious cavities extending into the pulp. The distribution and size of the caries lesions were similar to those found in contemporary adult populations in Africa and China living without access to dental care. Most lesions had a hypermineralized zone in the dentin at the advancing front of the carious cavities as revealed by micro-computed tomography. This biological dentin reaction combined with the morphology of the cavities might indicate that some temporary topical pain relief and intervention treatment slowed down the rate of lesion progression. This is indirectly supported by examination of cavities of similar size and depth from a contemporary population without access to dental health care. In contrast to the lesions in the Roman teeth, these lesions did not exhibit a hypermineralized dentin reaction. We investigated whether the Pb isotopic composition of enamel and/or dentin of a single tooth matched that of a sample of an ancient Forum water lead pipe. The Pb isotopic composition of the tooth did not match that of the tube, suggesting that the subjects were exposed to different Pb sources during their lifetime other than the lead tubes.


Assuntos
Cárie Dentária/história , Adulto , Cárie Dentária/metabolismo , Polpa Dentária/patologia , Dentina/patologia , História Antiga , Humanos , Chumbo/análise , Cidade de Roma , Cárie Radicular/história , Abastecimento de Água/análise , Microtomografia por Raio-X
8.
AJNR Am J Neuroradiol ; 43(5): 682-688, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35422419

RESUMO

BACKGROUND AND PURPOSE: Currently, contrast-enhancing margins on T1WI are used to guide treatment of gliomas, yet tumor invasion beyond the contrast-enhancing region is a known confounding factor. Therefore, this study used postmortem tissue samples aligned with clinically acquired MRIs to quantify the relationship between intensity values and cellularity as well as to develop a radio-pathomic model to predict cellularity using MR imaging data. MATERIALS AND METHODS: This single-institution study used 93 samples collected at postmortem examination from 44 patients with brain cancer. Tissue samples were processed, stained with H&E, and digitized for nuclei segmentation and cell density calculation. Pre- and postgadolinium contrast T1WI, T2 FLAIR, and ADC images were collected from each patient's final acquisition before death. In-house software was used to align tissue samples to the FLAIR image via manually defined control points. Mixed-effects models were used to assess the relationship between single-image intensity and cellularity for each image. An ensemble learner was trained to predict cellularity using 5 × 5 voxel tiles from each image, with a two-thirds to one-third train-test split for validation. RESULTS: Single-image analyses found subtle associations between image intensity and cellularity, with a less pronounced relationship in patients with glioblastoma. The radio-pathomic model accurately predicted cellularity in the test set (root mean squared error = 1015 cells/mm2) and identified regions of hypercellularity beyond the contrast-enhancing region. CONCLUSIONS: A radio-pathomic model for cellularity trained with tissue samples acquired at postmortem examination is able to identify regions of hypercellular tumor beyond traditional imaging signatures.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Contagem de Células , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia , Glioma/diagnóstico por imagem , Glioma/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Margens de Excisão
9.
Eur Cell Mater ; 22: 168-76; discussion 176-7, 2011 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-21932193

RESUMO

Modification of tissue engineering scaffolds with bioactive molecules is a potential strategy for modulating cell behavior and guiding tissue regeneration. While adhesion to RGD peptides has been shown to inhibit in vitro chondrogenesis, the effects of extracellular matrix (ECM)-mimetic ligands with complex secondary and tertiary structures are unknown. This study aimed to determine whether collagen- and fibronectin-mimetic ligands would retain biologic functionality in three-dimensional (3D) hydrogels, whether different ECM-mimetic ligands differentially influence in vitro chondrogenesis, and if effects of ligands on differentiation depend on soluble biochemical stimuli. A linear RGD peptide, a recombinant fibronectin fragment containing the seven to ten Type III repeats (FnIII7-10) and a triple helical, collagen mimetic peptide with the GFOGER motif were covalently coupled to agarose gels using the sulfo-SANPAH crosslinker, and bone marrow stromal cells (BMSCs) were cultured within the 3D hydrogels. The ligands retained biologic functionality within the agarose gels and promoted density-dependent BMSC spreading. Interactions with all adhesive ligands inhibited stimulation by chondrogenic factors of collagen Type II and aggrecan mRNA levels and deposition of sulfated glycosaminoglycans. In medium containing fetal bovine serum, interactions with the GFOGER peptide enhanced mRNA expression of the osteogenic gene osteocalcin whereas FnIII7-10 inhibited osteocalcin expression. In conclusion, modification of agarose hydrogels with ECM-mimetic ligands can influence the differentiation of BMSCs in a manner that depends strongly on the presence and nature of soluble biochemical stimuli.


Assuntos
Células da Medula Óssea/metabolismo , Condrogênese , Colágeno/metabolismo , Fibronectinas/metabolismo , Células Estromais/metabolismo , Agrecanas/metabolismo , Animais , Materiais Biocompatíveis , Células da Medula Óssea/citologia , Bovinos , Diferenciação Celular , Células Cultivadas , Colágeno Tipo II/metabolismo , Matriz Extracelular/metabolismo , Glicosaminoglicanos/biossíntese , Hidrogéis , Integrinas/metabolismo , Ligantes , RNA Mensageiro/biossíntese , Sefarose , Células Estromais/citologia , Engenharia Tecidual/métodos , Alicerces Teciduais
10.
Geochim Cosmochim Acta ; 287: 50-64, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34354297

RESUMO

The application of U isotopes in carbonates as a paleo-ocean oxygenation proxy is based on the critical assumption that the calcareous shell-building organisms incorporate U into their shells without fractionation relative to the U isotopic composition of ambient seawater. Recent studies claim a small, but resolvable, isotopic offset during abiotic and biogenic aragonite precipitation, whereas no isotope fractionation has been recorded during calcite precipitation. Although aragonite is meta-stable and not preserved over geological timescales (>1 Myr) and U precipitates during diagenesis, the U isotope composition of biogenic aragonite is important because aragonite precipitation is an important U sink to carbonate sediments. In contrast, low-magnesium calcite (LMC) is preserved over geological timescales and may provide a reliable fingerprint of ancient ocean chemistry. Therefore, a more general study is needed that compares U isotope compositions of primary marine biogenic carbonate precipitates. We report the U isotope compositions of 32 modern samples from geographically distinct localities in the Atlantic Ocean including corals (Scleractinia, Octocorallia), brachiopods (Articulata), molluscs (Tellina Listeri, Codahia Obicularis) and barnacles as well as one fossil mollusc. These samples reflect variable primary minerals, water temperatures, water depths, pH-values of ambient water, and U concentrations. Several seawater samples have also been measured to compare our methods with those of previously published studies. The analyzed modern corals and brachiopods display U isotopic compositions that are indistinguishable from modern seawater. This suggests that these carbonates have the potential to faithfully record the U isotopic composition of the surrounding seawater in which they form. The analyzed brachiopods are of particular interest as they are composed of the calcium carbonate polymorph LMC that is stable over geological timescales. While this study shows for the first time that LMC phases are robust targets in ancient samples, their low U abundance presents analytical challenges for precise U isotope analyses. We also show that two barnacle shells collected with ambient seawater have U isotopic compositions that are both lighter and heavier than the ambient seawater. The mechanism to explain this offset is not determined, but it demonstrates that at least barnacle shells are not representative of the seawater in which they last lived. Two of three partially fossilized mollusc shells also show resolvable offsets from seawater, likely indicating secondary processes that are known to shift or fractionate U isotopes. Collectively, our new data indicate that: 1) aragonite delivers U with a seawater composition to carbonate sediments, and 2) LMC shells of brachiopods that are stable over geological timescales may be more suitable for reconstructing the U isotope composition of ancient oceans.

11.
J Cell Biol ; 48(2): 291-302, 1971 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-5543401

RESUMO

Through the use of combined spectrophotometric and electron microscope techniques, large amplitude swelling of rat liver mitochondria has been described as an ordered sequence of ultrastructural transitions. Prior to the actual swelling, mitochondria undergo two major conformational changes: condensed to twisted form and twisted to orthodox form. This sequence is independent of (a) the nature of swelling agents and (b) the time of onset of swelling. Agents that delay the onset of swelling act to increase the duration of the twisted conformation. Agents that prevent extensive swelling hold mitochondria in intermediate conformations. Gross swelling, immediately preceded by a decrease in electron opacity of the matrix, involves the rupture of the outer membrane and expansion of the inner compartment of the mitochondrion.


Assuntos
Fígado/ultraestrutura , Trifosfato de Adenosina/farmacologia , Animais , Cálcio/farmacologia , Mitocôndrias , Dilatação Mitocondrial
12.
Science ; 286(5437): 90-4, 1999 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-10506566

RESUMO

The age of secondary carbonate mineralization in the martian meteorite ALH84001 was determined to be 3.90 +/- 0.04 billion years by rubidium-strontium (Rb-Sr) dating and 4.04 +/- 0.10 billion years by lead-lead (Pb-Pb) dating. The Rb-Sr and Pb-Pb isochrons are defined by leachates of a mixture of high-graded carbonate (visually estimated as approximately 5 percent), whitlockite (trace), and orthopyroxene (approximately 95 percent). The carbonate formation age is contemporaneous with a period in martian history when the surface is thought to have had flowing water, but also was undergoing heavy bombardment by meteorites. Therefore, this age does not distinguish between aqueous and impact origins for the carbonates.


Assuntos
Carbonatos , Marte , Meteoroides , Cálcio/análise , Fosfatos de Cálcio , Carbonatos/análise , Ferro/análise , Isótopos/análise , Chumbo/análise , Magnésio/análise , Minerais , Radioisótopos de Rubídio/análise , Isótopos de Estrôncio/análise
13.
Sci Adv ; 5(5): eaav2244, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31049395

RESUMO

Oxytocin is used in approximately half of all births in the United States during labor induction and/or augmentation. However, the effects of maternal oxytocin administration on offspring development have not been fully characterized. Here, we used the socially monogamous prairie vole to examine the hypothesis that oxytocin exposure at birth can have long-term developmental consequences. Maternally administered oxytocin increased methylation of the oxytocin receptor (Oxtr) in the fetal brain. As adults, oxytocin-exposed voles were more gregarious, with increased alloparental caregiving toward pups and increased close social contact with other adults. Cross-fostering indicated that these effects were the result of direct action on the offspring, rather than indirect effects via postnatal changes in maternal behavior. Male oxytocin-exposed offspring had increased oxytocin receptor density and expression in the brain as adults. These results show that long-term effects of perinatal oxytocin may be mediated by an epigenetic mechanism.


Assuntos
Arvicolinae/fisiologia , Comportamento Animal/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Ocitócicos/farmacologia , Ocitocina/farmacologia , Parto/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Feminino , Masculino , Metilação/efeitos dos fármacos , Ocitócicos/administração & dosagem , Ocitocina/administração & dosagem , Gravidez , Receptores de Ocitocina/metabolismo , Comportamento Social
14.
AJNR Am J Neuroradiol ; 40(4): 626-633, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30923088

RESUMO

BACKGROUND AND PURPOSE: DSC-MR imaging using preload, intermediate (60°) flip angle and postprocessing leakage correction has gained traction as a standard methodology. Simulations suggest that DSC-MR imaging with flip angle = 30° and no preload yields relative CBV practically equivalent to the reference standard. This study tested this hypothesis in vivo. MATERIALS AND METHODS: Eighty-four patients with brain lesions were enrolled in this 3-institution study. Forty-three patients satisfied the inclusion criteria. DSC-MR imaging (3T, single-dose gadobutrol, gradient recalled-echo-EPI, TE = 20-35 ms, TR = 1.2-1.63 seconds) was performed twice for each patient, with flip angle = 30°-35° and no preload (P-), which provided preload (P+) for the subsequent intermediate flip angle = 60°. Normalized relative CBV and standardized relative CBV maps were generated, including postprocessing with contrast agent leakage correction (C+) and without (C-) contrast agent leakage correction. Contrast-enhancing lesion volume, mean relative CBV, and contrast-to-noise ratio obtained with 30°/P-/C-, 30°/P-/C+, and 60°/P+/C- were compared with 60°/P+/C+ using the Lin concordance correlation coefficient and Bland-Altman analysis. Equivalence between the 30°/P-/C+ and 60°/P+/C+ protocols and the temporal SNR for the 30°/P- and 60°/P+ DSC-MR imaging data was also determined. RESULTS: Compared with 60°/P+/C+, 30°/P-/C+ had closest mean standardized relative CBV (P = .61), highest Lin concordance correlation coefficient (0.96), and lowest Bland-Altman bias (µ = 1.89), compared with 30°/P-/C- (P = .02, Lin concordance correlation coefficient = 0.59, µ = 14.6) and 60°/P+/C- (P = .03, Lin concordance correlation coefficient = 0.88, µ = -10.1) with no statistical difference in contrast-to-noise ratios across protocols. The normalized relative CBV and standardized relative CBV were statistically equivalent at the 10% level using either the 30°/P-/C+ or 60°/P+/C+ protocols. Temporal SNR was not significantly different for 30°/P- and 60°/P+ (P = .06). CONCLUSIONS: Tumor relative CBV derived from low-flip angle, no-preload DSC-MR imaging with leakage correction is an attractive single-dose alternative to the higher dose reference standard.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/normas , Imageamento por Ressonância Magnética/normas , Neuroimagem/normas , Adulto , Neoplasias Encefálicas/patologia , Consenso , Meios de Contraste , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Neuroimagem/métodos , Compostos Organometálicos , Padrões de Referência
15.
Osteoarthritis Cartilage ; 16(9): 1092-100, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18294870

RESUMO

OBJECTIVE: The goal of this study was to characterize the proteoglycan (PG) production and processing by bone marrow stromal cells (BMSCs) within a tissue engineered construct. METHODS: Bovine BMSCs and articular chondrocytes (ACs) were isolated from an immature calf, seeded into agarose gels, and cultured up to 32 days in the presence of TGF-beta1. The localization of various PGs was examined by immunofluorescence and histological staining. The role of proteolytic enzymes in construct development was further investigated by examining the effects of aggrecanase and MMP inhibitors on PG accumulation, aggrecan processing, and construct mechanics. RESULTS: BMSCs developed a matrix rich in sulfated-glycosaminoglycans (sGAG) and full-length aggrecan, but had low levels of versican. The BMSC constructs had less collagen II and aggrecan compared to the AC constructs cultured under identical conditions. AC constructs also had high levels of pericellular collagen VI, while BMSCs had a pericellular matrix containing little collagen VI and greater levels of decorin, biglycan, and fibronectin. Treatment with the aggrecanase inhibitor did not affect sGAG accumulation or the dynamic moduli of the BMSC constructs. The MMP inhibitor slightly but significantly inhibited sGAG accumulation and lowered the dynamic moduli of BMSC constructs. CONCLUSIONS: The results of this preliminary study indicate that long-term culture of BMSCs with TGF-beta1 promotes the development of an aggrecan-rich matrix characteristic of native articular cartilage; however, BMSCs accumulate significantly lower levels of sGAG and assemble distinct pericellular microenvironments compared to ACs. PG turnover does not appear to play a major role in the development of tissue engineered cartilage constructs by BMSCs.


Assuntos
Cartilagem Articular/citologia , Condrócitos/citologia , Matriz Extracelular/metabolismo , Proteoglicanas/metabolismo , Engenharia Tecidual/métodos , Proteínas ADAM/metabolismo , Proteína ADAMTS4 , Animais , Biglicano , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Cartilagem Articular/metabolismo , Bovinos , Condrócitos/metabolismo , Condrócitos/transplante , Condrogênese/fisiologia , Colágeno Tipo VI/metabolismo , Decorina , Proteínas da Matriz Extracelular/metabolismo , Fibronectinas/metabolismo , Imuno-Histoquímica , Pró-Colágeno N-Endopeptidase/metabolismo , Estresse Mecânico , Células Estromais/citologia , Células Estromais/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
16.
Bone Joint J ; 100-B(12): 1592-1599, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30499312

RESUMO

AIMS: The primary aim of this study was to compare the wear properties of vitamin E-diffused, highly crosslinked polyethylene (VEPE) and one formulation of moderately crosslinked and mechanically annealed ultra-high molecular weight polyethylene (ModXLPE) in patients five years after primary total hip arthroplasty (THA). The secondary aim was to assess the clinical results of patients treated with VEPE by evaluating patient-reported outcome measures (PROMs), radiological evidence of fixation, and the incidence of mechanical failure. PATIENTS AND METHODS: A total of 208 patients (221 THAs) from four international centres were recruited into a prospective study involving radiostereometric analysis (RSA) and the assessment of clinical outcomes. A total of 193 hips (87%) were reviewed at the five-year follow-up. Of these, 136 (70%) received VEPE (vs ModXLPE) liners and 68 (35%) received ceramic (vs metal) femoral heads. PROMs and radiographs were collected preoperatively and at one, two, and five years postoperatively. In addition, RSA images were collected to measure PE wear postoperatively and at one, two, and five years after surgery. RESULTS: We observed similar bedding in one year postoperatively and wear two years postoperatively between the two types of liner. However, there was significantly more penetration of the femoral head in the ModXLPE cohort compared with the VEPE cohort five years postoperatively (p < 0.001). The only variables independently predictive of increased wear were ModXLPE (vs VEPE) liner type (ß = 0.22, p = 0.010) and metal (vs ceramic) femoral head (ß = 0.21, p = 0.013). There was no association between increased wear and the development of radiolucency (p = 0.866) or PROMs. No patient had evidence of osteolysis. CONCLUSION: Five years postoperatively, patients with VEPE (vs ModXLPE) and ceramic (vs metal) femoral heads had decreased wear. The rates of wear for both liners were very low and have not led to any osteolysis or implant failure due to aseptic loosening.


Assuntos
Artroplastia de Quadril/métodos , Reagentes de Ligações Cruzadas , Prótese de Quadril , Polietilenos/química , Vitamina E/análise , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Quadril/cirurgia , Estudos Prospectivos , Desenho de Prótese , Análise Radioestereométrica , Estresse Mecânico , Fatores de Tempo
17.
Nat Commun ; 8: 14066, 2017 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-28117834

RESUMO

The catastrophic disruption of the L chondrite parent body in the asteroid belt c. 470 Ma initiated a prolonged meteorite bombardment of Earth that started in the Ordovician and continues today. Abundant L chondrite meteorites in Middle Ordovician strata have been interpreted to be the consequence of the asteroid breakup event. Here we report a zircon U-Pb date of 467.50±0.28 Ma from a distinct bed within the meteorite-bearing interval of southern Sweden that, combined with published cosmic-ray exposure ages of co-occurring meteoritic material, provides a precise age for the L chondrite breakup at 468.0±0.3 Ma. The new zircon date requires significant revision of the Ordovician timescale that has implications for the understanding of the astrogeobiologic development during this period. It has been suggested that the Middle Ordovician meteorite bombardment played a crucial role in the Great Ordovician Biodiversification Event, but this study shows that the two phenomena were unrelated.


Assuntos
Biodiversidade , Planeta Terra , Meteoroides , Planetas Menores , Fenômenos Geológicos , Datação Radiométrica , Silicatos/análise , Suécia , Fatores de Tempo , Zircônio/análise
18.
Bone Joint J ; 99-B(4 Supple B): 33-40, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28363892

RESUMO

AIMS: Our first aim was to determine whether there are significant changes in the level of metal ions in the blood at mid-term follow-up, in patients with an Articular Surface Replacement (ASR) arthroplasty. Secondly, we sought to identify risk factors for any increases. PATIENTS AND METHODS: The study involved 435 patients who underwent unilateral, metal-on-metal (MoM) hip resurfacing (HRA) or total hip arthroplasty (THA). These patients all had one measurement of the level of metal ions in the blood before seven years had passed post-operatively (early evaluation) and one after seven years had passed post-operatively (mid-term evaluation). Changes in ion levels were tested using a Wilcoxon signed-rank test. We identified subgroups at the highest risk of increase using a multivariable linear logistic regression model. RESULTS: There were significant increases in the levels of metal ions for patients who underwent both MoM HRA (Chromium (Cr): 0.5 parts per billion (ppb); Cobalt (Co): 1.1 ppb) and MoM THA (Cr: 0.5 ppb; Co: 0.7 ppb). In a multivariable model considering MoM HRAs, the change in the levels of metal ions was influenced by female gender (Co: Odds Ratio (OR) 1.42; p = 0.002 and Cr: OR 1.08; p = 0.006). The change was found to be irrespective of the initial level for the MoM HRAs, whereas there was a negative relationship between the initial level and the change in the level for those with a MoM THA (Co: OR -0.43; p < 0.001 and Cr: OR -0.14; p = 0.033). CONCLUSION: The levels of metal ions in the blood increase significantly over the period until mid-term follow-up in patients with both a MoM HRA and those with a MoM THA. We recommend that the levels of metal ions be measured most frequently for women with a MoM HRA. While those with a MoM THA appear to stabilise at a certain level, the accuracy of this trend is not yet clear. Vigilant follow-up is still recommended. Cite this article: Bone Joint J 2017;99-B(4 Supple B):33-40.


Assuntos
Artroplastia de Quadril/efeitos adversos , Cromo/sangue , Cobalto/sangue , Prótese de Quadril/efeitos adversos , Idoso , Artroplastia de Quadril/instrumentação , Artroplastia de Quadril/métodos , Feminino , Seguimentos , Humanos , Masculino , Próteses Articulares Metal-Metal/efeitos adversos , Pessoa de Meia-Idade , Estudos Prospectivos , Desenho de Prótese , Fatores de Risco , Fatores Sexuais
19.
Disabil Rehabil ; 28(10): 629-36, 2006 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-16690576

RESUMO

AIM: To estimate associations between possible predictors of functional disability outcome at 5 years in a working adult population cohort of survivors of major traumatic injury and to develop a prognostic model of outcome. DESIGN: Population based retrospective cohort study. POPULATION: Persons who had experienced major traumatic injury (Injury Seventy Score >15) in the area of the former Yorkshire Regional Health Authority during the period 30 September 1988 to 1 October 1989 and who survived for 5 years (average 5.3 years). METHODS: The same interviewer saw each survivor at their home and used the OPCS Adult Disability Schedule to ascertain levels of functional disability. Disability scores for each survivor were then combined in accordance with the OPCS guidance to calculate a level of disability between 0 (no disability) to 10 (maximum disability). The OPCS level was then dichotomised with a cut-point at 4/5. Possible predictor and confounding variables from pre-injury, injury and post-injury periods were modelled in a logistic regression to identify those that predicted outcome level. Two reduced models were developed to allow early prognosis of late outcome. RESULTS: The full model correctly classified 91% of observed outcomes. Inpatient length of stay OR 1.031 (95% CI 1.014,1.048) per day predicted poorer 5-year outcome; Glasgow Coma Score OR 0.790(0.629,0.992) per 1 point increase; stay in Intensive Care Unit OR 0.931 (0.877,0.987) per day; attainment of degree-level education OR 0.014 (0.000,0.707); single civil status OR 0.110 (0.013,0.908); being taken initially to a hospital with a neurosurgical facility OR 0.064(0.010,0.420); being in paid work during the 2 weeks before index injury OR 0.093(0.009,0.969) predicted better 5-year disability outcome. Two reduced models were constructed that included a simple set of variables, one of these models excluded any rehabilitation variables but still correctly classified 85% of the observed outcomes. CONCLUSION: As well as level of traumatic brain injury (TBI) and total inpatient stay, Pre-injury educational attainment and employment, civil status, immediate care in a hospital with a neurosurgical facility and stay in an Intensive Care Unit determined 5-year outcome. It is possible to efficiently predict outcome at an early stage. Previous work on predictors of disablement have suffered from large selection and attrition biases.


Assuntos
Recuperação de Função Fisiológica , Ferimentos e Lesões/reabilitação , Adolescente , Adulto , Idoso , Lesões Encefálicas/diagnóstico , Lesões Encefálicas/reabilitação , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Análise Multivariada , Prognóstico , Estudos Retrospectivos , Sobreviventes/estatística & dados numéricos , Índices de Gravidade do Trauma , Reino Unido , Ferimentos e Lesões/diagnóstico
20.
Br J Nurs ; 15(9): 520-3, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16723928

RESUMO

AIM: To assess whether a pilot study conducted in the UK achieved its objective to reduce admissions to hospital and bed days in patients identified as suitable recipients of case management by community matrons. BACKGROUND: The Department of Health has advocated the use of nurse-led case management to improve the coordination of care and prevent inappropriate hospital admissions. METHOD: 66 patients and another 66 controls were identified for the 'Evercare' caseload according to criteria set by United Healthcare. Admissions data for the six months after entry into the study were collected from the hospital information system. FINDINGS: admission rates in both the control and intervention group decreased over time and there was no significant difference in rates between the two groups at six months. There was no demonstrable effect on length of stay either. Users were satisfied with the service and nurses cited several clinical stories implying benefits for individual patients.


Assuntos
Administração de Caso/organização & administração , Enfermagem em Saúde Comunitária/organização & administração , Tempo de Internação/estatística & dados numéricos , Enfermeiros Administradores/organização & administração , Admissão do Paciente/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Enfermagem em Saúde Comunitária/educação , Continuidade da Assistência ao Paciente/organização & administração , Feminino , Seguimentos , Humanos , Masculino , Modelos de Enfermagem , Enfermeiros Administradores/educação , Papel do Profissional de Enfermagem , Pesquisa em Avaliação de Enfermagem , Avaliação de Resultados em Cuidados de Saúde , Projetos Piloto , Atenção Primária à Saúde/organização & administração , Avaliação de Programas e Projetos de Saúde , Projetos de Pesquisa , Gestão da Qualidade Total/organização & administração
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