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1.
Colloids Surf B Biointerfaces ; 180: 245-253, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31055151

RESUMO

The lack of bioactivity of titanium (Ti) is one of the main drawbacks for its application in biomedical implants since it can considerable reduce its osseointegration capacities. One strategy to overcome this limitation is the coating of Ti with hydroxyapatite (HA), which presents similar chemical composition than bone. Nonetheless, most of the strategies currently used generate a non-stable coating and may produce the formation of amorphous phases when high temperatures are used. Herein, we proposed to generate a Ti-HA composite coating on Ti surface to improve the stability of the bioactive coating. The coating was produced by cold gas spraying, which uses relatively low temperatures, and compared to a Ti coating. The coating was thoroughly characterized in terms of morphology, roughness, porosity and phase composition. In addition, the coating was mechanically characterized using a tensile loading machine. Finally, biological response was evaluated after seeding SaOS-2 osteoblasts and measuring cell adhesion, proliferation and differentiation. The novel Ti-HA coating presented high porosity and high adhesion and bond strengths. No change in HA phases was observed after coating formation. Moreover, osteoblast-like cells adhered, proliferated and differentiated on Ti-HA coated surfaces suggesting that the novel coating might be a good candidate for biomedical applications.


Assuntos
Tecnologia Biomédica/métodos , Materiais Revestidos Biocompatíveis/química , Temperatura Baixa , Durapatita/química , Gases/química , Titânio/química , Linhagem Celular , Humanos , Osteoblastos/citologia , Porosidade , Soluções , Propriedades de Superfície , Resistência à Tração , Difração de Raios X
2.
Arch Dis Child Fetal Neonatal Ed ; 103(1): F15-F21, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28988160

RESUMO

BACKGROUND: We tested the hypothesis that routine MRI would improve the care and well-being of preterm infants and their families. DESIGN: Parallel-group randomised trial (1.1 allocation; intention-to-treat) with nested diagnostic and cost evaluations (EudraCT 2009-011602-42). SETTING: Participants from 14 London hospitals, imaged at a single centre. PATIENTS: 511 infants born before 33 weeks gestation underwent both MRI and ultrasound around term. 255 were randomly allocated (siblings together) to receive only MRI results and 255 only ultrasound from a paediatrician unaware of unallocated results; one withdrew before allocation. MAIN OUTCOME MEASURES: Maternal anxiety, measured by the State-Trait Anxiety inventory (STAI) assessed in 206/214 mothers receiving MRI and 217/220 receiving ultrasound. Secondary outcomes included: prediction of neurodevelopment, health-related costs and quality of life. RESULTS: After MRI, STAI fell from 36.81 (95% CI 35.18 to 38.44) to 32.77 (95% CI 31.54 to 34.01), 31.87 (95% CI 30.63 to 33.12) and 31.82 (95% CI 30.65 to 33.00) at 14 days, 12 and 20 months, respectively. STAI fell less after ultrasound: from 37.59 (95% CI 36.00 to 39.18) to 33.97 (95% CI 32.78 to 35.17), 33.43 (95% CI 32.22 to 34.63) and 33.63 (95% CI 32.49 to 34.77), p=0.02. There were no differences in health-related quality of life. MRI predicted moderate or severe functional motor impairment at 20 months slightly better than ultrasound (area under the receiver operator characteristic curve (CI) 0.74; 0.66 to 0.83 vs 0.64; 0.56 to 0.72, p=0.01) but cost £315 (CI £295-£336) more per infant. CONCLUSIONS: MRI increased costs and provided only modest benefits. TRIAL REGISTRATION: ClinicalTrials.gov NCT01049594 https://clinicaltrials.gov/ct2/show/NCT01049594. EudraCT: EudraCT: 2009-011602-42 (https://www.clinicaltrialsregister.eu/).


Assuntos
Ansiedade , Encéfalo , Imageamento por Ressonância Magnética , Comportamento Materno/psicologia , Ultrassonografia , Adulto , Ansiedade/diagnóstico , Ansiedade/etiologia , Encéfalo/diagnóstico por imagem , Encéfalo/crescimento & desenvolvimento , Desenvolvimento Infantil , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro/fisiologia , Imageamento por Ressonância Magnética/economia , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/psicologia , Masculino , Exame Neurológico/métodos , Exame Neurológico/estatística & dados numéricos , Cuidado Pós-Natal/economia , Cuidado Pós-Natal/métodos , Resultado do Tratamento , Ultrassonografia/economia , Ultrassonografia/métodos , Ultrassonografia/psicologia
3.
Sci Rep ; 7(1): 13250, 2017 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-29038505

RESUMO

Preterm infants who develop neurodevelopmental impairment do not always have recognized abnormalities on cerebral ultrasound, a modality routinely used to assess prognosis. In a high proportion of infants, MRI detects punctate white matter lesions that are not seen on ultrasonography. To determine the relation of punctate lesions to brain development and early neurodevelopmental outcome we used multimodal brain MRI to study a large cohort of preterm infants. Punctate lesions without other focal cerebral or cerebellar lesions were detected at term equivalent age in 123 (24.3%) (59 male) of the 506 infants, predominantly in the centrum semiovale and corona radiata. Infants with lesions had higher gestational age, birth weight, and less chronic lung disease. Punctate lesions showed a dose dependent relation to abnormalities in white matter microstructure, assessed with tract-based spatial statistics, and reduced thalamic volume (p < 0.0001), and predicted unfavourable motor outcome at a median (range) corrected age of 20.2 (18.4-26.3) months with sensitivity (95% confidence intervals) 71 (43-88) and specificity 72 (69-77). Punctate white matter lesions without associated cerebral lesions are common in preterm infants currently not regarded as at highest risk for cerebral injury, and are associated with widespread neuroanatomical abnormalities and adverse early neurodevelopmental outcome.


Assuntos
Substância Branca/patologia , Substância Branca/fisiopatologia , Lesões Encefálicas/diagnóstico por imagem , Lesões Encefálicas/patologia , Lesões Encefálicas/fisiopatologia , Imagem de Tensor de Difusão , Feminino , Humanos , Lactente , Recém-Nascido Prematuro , Imageamento por Ressonância Magnética , Masculino , Substância Branca/diagnóstico por imagem
4.
Ann Neurol ; 82(2): 233-246, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28719076

RESUMO

OBJECTIVE: Premature birth is associated with numerous complex abnormalities of white and gray matter and a high incidence of long-term neurocognitive impairment. An integrated understanding of these abnormalities and their association with clinical events is lacking. The aim of this study was to identify specific patterns of abnormal cerebral development and their antenatal and postnatal antecedents. METHODS: In a prospective cohort of 449 infants (226 male), we performed a multivariate and data-driven analysis combining multiple imaging modalities. Using canonical correlation analysis, we sought separable multimodal imaging markers associated with specific clinical and environmental factors and correlated to neurodevelopmental outcome at 2 years. RESULTS: We found five independent patterns of neuroanatomical variation that related to clinical factors including age, prematurity, sex, intrauterine complications, and postnatal adversity. We also confirmed the association between imaging markers of neuroanatomical abnormality and poor cognitive and motor outcomes at 2 years. INTERPRETATION: This data-driven approach defined novel and clinically relevant imaging markers of cerebral maldevelopment, which offer new insights into the nature of preterm brain injury. Ann Neurol 2017;82:233-246.


Assuntos
Encéfalo/anormalidades , Encéfalo/crescimento & desenvolvimento , Processamento de Imagem Assistida por Computador , Recém-Nascido Prematuro/fisiologia , Recém-Nascido Prematuro/psicologia , Anisotropia , Pré-Escolar , Disfunção Cognitiva/patologia , Feminino , Humanos , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Modelos Estatísticos , Transtornos Motores/patologia , Estudos Prospectivos , Fatores de Risco
5.
Proc Natl Acad Sci U S A ; 112(20): 6485-90, 2015 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-25941391

RESUMO

Connections between the thalamus and cortex develop rapidly before birth, and aberrant cerebral maturation during this period may underlie a number of neurodevelopmental disorders. To define functional thalamocortical connectivity at the normal time of birth, we used functional MRI (fMRI) to measure blood oxygen level-dependent (BOLD) signals in 66 infants, 47 of whom were at high risk of neurocognitive impairment because of birth before 33 wk of gestation and 19 of whom were term infants. We segmented the thalamus based on correlation with functionally defined cortical components using independent component analysis (ICA) and seed-based correlations. After parcellating the cortex using ICA and segmenting the thalamus based on dominant connections with cortical parcellations, we observed a near-facsimile of the adult functional parcellation. Additional analysis revealed that BOLD signal in heteromodal association cortex typically had more widespread and overlapping thalamic representations than primary sensory cortex. Notably, more extreme prematurity was associated with increased functional connectivity between thalamus and lateral primary sensory cortex but reduced connectivity between thalamus and cortex in the prefrontal, insular and anterior cingulate regions. This work suggests that, in early infancy, functional integration through thalamocortical connections depends on significant functional overlap in the topographic organization of the thalamus and that the experience of premature extrauterine life modulates network development, altering the maturation of networks thought to support salience, executive, integrative, and cognitive functions.


Assuntos
Córtex Cerebral/fisiologia , Desenvolvimento Infantil/fisiologia , Tálamo/fisiologia , Fatores Etários , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Imageamento por Ressonância Magnética , Vias Neurais/fisiologia , Oxigênio/sangue
6.
Food Nutr Bull ; 35(3 Suppl): S145-53, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25902585

RESUMO

BACKGROUND: The "Cooking and Active Leisure" Tu y Alícia por la Salud (CAL-TAS) Program is a school-based pilot that addresses healthy lifestyle needs of Spanish secondary school students with initiatives that research has proven to improve dietary and physical activity behaviors. OBJECTIVE: The objectives were to perform a Program Impact Pathways (PIP) analysis to describe key activities and processes of the CAL-TAS Program, identify Critical Quality Control Points (CCPs), and identify a suite of common indicators of healthy lifestyles to be applied across participant schools. METHODS: The CAL-TAS Program designers and implementation team developed this PIP analysis through an iterative process and presented the results for feedback at the seven-country Healthy Lifestyles Program Evaluation Workshop held in Granada, Spain, 13-14 September 2013, under the auspices of the Mondelez International Foundation. RESULTS: The team identified three PIP CCPs: teachers' motivation and training, changes in students' knowledge of healthy lifestyles, and changes in students' healthy lifestyle behavior. The selected indicators of the program's impact on healthy lifestyles are adequacy of food intake, level of knowledge of healthy lifestyles gained, and adequacy of physical activity level according to World Health Organization recommendations. A clear definition of impact indicators, as well as collection of accurate data on healthy lifestyle behaviors and knowledge, is essential to understanding the effectiveness of this program before it can be scaled up. CONCLUSIONS: CAL-TAS is an effective secondary school-based program encouraging healthy lifestyles. The PIP analysis was instrumental in identifying CCPs to sustain and improve the quality of the program. The team hopes to sustain and improve the program through these program evaluation recommendations.


Assuntos
Culinária , Promoção da Saúde/métodos , Estilo de Vida , Avaliação de Programas e Projetos de Saúde , Serviços de Saúde Escolar , Adolescente , Dieta , Exercício Físico , Docentes , Comportamento Alimentar , Comportamentos Relacionados com a Saúde , Educação em Saúde/métodos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Ciências da Nutrição/educação , Obesidade/prevenção & controle , Espanha
7.
Acta Paediatr ; 102(4): 360-5, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23298288

RESUMO

AIM: To explore parental information and communication needs during their baby's care in the neonatal unit with a focus on brain imaging and neurological prognosis. METHODS: Eighteen parents recruited from one neonatal unit in the United Kingdom participated in semi-structured qualitative interviews using a grounded theory approach. The topic guide focused on information received about neonatal brain imaging, diagnosis and prognosis, emotional impact and support. RESULTS: Parents expressed different information needs influenced by their history, expectations, coping strategies and experiences. Most felt they initially were passive recipients of information and attempted to gain control of the information flow. Nurses were the main providers of information; doctors and other parents were also valuable. Attending ward rounds was important. Some parents felt accessing specific information such as the results of brain imaging could be difficult. Concerns about long-term developmental outcomes and the need for information did not diminish over time. The emotional impact of having a preterm baby had a negative effect on parents' ability to retain information, and all had an ongoing need for reassurance. CONCLUSION: The findings provide insights about the needs and experiences of parents who have a continuing requirement for information about their infant's care, development and prognosis.


Assuntos
Adaptação Psicológica , Encéfalo/crescimento & desenvolvimento , Pais/psicologia , Nascimento Prematuro/psicologia , Estresse Psicológico/etiologia , Comunicação , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Disseminação de Informação/métodos , Unidades de Terapia Intensiva Neonatal/organização & administração , Entrevistas como Assunto , Masculino , Neuroimagem/métodos , Relações Profissional-Família , Prognóstico , Pesquisa Qualitativa , Apoio Social , Reino Unido , Recursos Humanos
8.
Eur J Gastroenterol Hepatol ; 18(5): 483-91, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16607142

RESUMO

OBJECTIVES: The ability of the gliadin fraction of wheat gluten to exacerbate coeliac disease is well documented. We investigated the possible toxicity of high molecular weight glutenin subunits (HMW-GS) in coeliac disease in vitro using gluten-sensitive T cells, and in vivo with challenge studies in patient volunteers. METHODS: A mixture of four HMW-GS was chemically separated from wheat flour and checked for purity by HPLC, SDS-PAGE and ELISA. T-cell lines, grown up from small intestinal biopsies from coeliac patients (n=17), were tested for their reactivity to HMW-GS. Adults with coeliac disease and who were on a gluten-free diet (n=3) underwent in-vivo challenges with HMW-GS. Duodenal biopsies, taken prior to the challenge and at intervals up to 6 h afterwards, were assessed for morphology, intra-epithelial lymphocyte count, and interleukin 15 (IL-15) expression, by immunohistochemistry. RESULTS: T-cell lines from 11 of 17 patients were stimulated by HMW-GS. There was a significant change in small intestinal morphology 4 h after commencing infusions with HMW-GS in all three subjects. For example villus height to crypt depth ratios were reduced in the three patients from 3.0+/-0.5 to 1.29+/-0.2, 2.53+/-0.7 to 0.81+/-0.6 and 3.0+/-0.7 to 1.85+/-0.3, P<0.0001 in all cases. There was increased expression of IL-15 in the small intestine from 2 h after the HMW-GS challenges. CONCLUSION: Mixed HMW-GS stimulate T-cell lines from some coeliac patients and exacerbate coeliac disease in vivo, inducing expression, within 2 h, of IL-15. This suggests an innate immune response to these proteins.


Assuntos
Doença Celíaca/patologia , Glutens/efeitos adversos , Triticum/química , Adolescente , Adulto , Idoso , Doença Celíaca/imunologia , Linhagem Celular , Dieta com Restrição de Proteínas , Epitopos/imunologia , Feminino , Glutens/administração & dosagem , Glutens/imunologia , Glutens/isolamento & purificação , Humanos , Imuno-Histoquímica/métodos , Interferon gama/imunologia , Interleucina-15/análise , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Intestino Delgado/imunologia , Intestino Delgado/patologia , Masculino , Pessoa de Meia-Idade , Peso Molecular , Linfócitos T/imunologia
9.
Horm Res ; 62(4): 191-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15375329

RESUMO

OBJECTIVES: The effects of triiodothyronine (T(3)) and hypoxia on 2,3-bisphosphoglycerate (2,3-BPG) studied in vitro are unclear. To clarify these effects we selected a more physiologic approach: the in vivo study in rabbits. We also present the changes produced by T(3) and hypoxia on phosphoglycerate mutase (PGAM), which requires 2,3-BPG as a cofactor, and 2,3-BPG synthase (BPGS), the enzyme responsible for 2,3-BPG synthesis in erythroblasts and reticulocytes. METHODS: Hyperthyroidism was induced by daily T(3) injection (250 microg/kg), hypoxia by a mixture of 90% nitrogen and 10% oxygen and hypothyroidism by propylthiouracil (PTU) added to drinking water. RESULTS: Both T(3) administration and hypoxic conditions increased 2,3-BPG levels and BPGS mRNA levels and activity in erythroblasts but not in reticulocytes. Unlike BPGS, both PGAM mRNA levels and activity were increased in erythroblasts and reticulocytes under hyperthyrodism and hypoxia. The antihormone PTU produced opposite effects to T(3). CONCLUSION: The results presented here suggest that both hyperthyroidism and hypoxia modulate in vivo red cell 2,3-BPG content by changes in the expression of BPGS. Similarly, the changes in PGAM activity are also explained by changes in its expression.


Assuntos
2,3-Difosfoglicerato/metabolismo , Bisfosfoglicerato Mutase/metabolismo , Eritroblastos/metabolismo , Hipóxia/metabolismo , Fosfoglicerato Mutase/metabolismo , Reticulócitos/metabolismo , Tri-Iodotironina/farmacologia , 2,3-Difosfoglicerato/sangue , Animais , Bisfosfoglicerato Mutase/sangue , Bisfosfoglicerato Mutase/genética , Hipertireoidismo/sangue , Hipertireoidismo/induzido quimicamente , Hipertireoidismo/metabolismo , Hipóxia/sangue , Masculino , Fosfoglicerato Mutase/sangue , Fosfoglicerato Mutase/genética , RNA Mensageiro/sangue , RNA Mensageiro/metabolismo , Coelhos
10.
Horm Res ; 59(1): 16-20, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12566730

RESUMO

AIM: In the present work, we studied the effects of hypoxia and triiodothyronine (T(3)) on phosphoglycerate mutase (PGAM) activity and expression in rabbit liver, brain, and skeletal muscle under in vivo conditions. METHODS: Hypoxia was induced in a methacrylate cage with a mixture of 90% nitrogen and 10% oxygen. Hyperthyroidism was induced daily by T(3) injection (250 microg/kg). RESULTS: Hypoxia increases the PGAM activity in liver and brain, tissues which possess type PGAM-BB isozyme, but does not affect the PGAM activity in muscle which possesses type PGAM-MM isozyme. T(3) administration increases the PGAM activity in muscle and liver, but does not affect the enzyme activity in the brain. In all cases, the activity changes in parallel with those of PGAM mRNA levels. CONCLUSION: The tissue-specific effects of hypoxia and T(3) could be explained by the tissue-specific distribution of both PGAM isozyme and T(3) receptors.


Assuntos
Encéfalo/enzimologia , Hipóxia/enzimologia , Fígado/enzimologia , Músculo Esquelético/enzimologia , Fosfoglicerato Mutase/metabolismo , Tri-Iodotironina/farmacologia , Animais , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Fosfoglicerato Mutase/genética , RNA Mensageiro/metabolismo , Coelhos
11.
Horm Res ; 57(1-2): 48-52, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12006720

RESUMO

BACKGROUND: We previously showed that triiodothyronine (T3) stimulates muscle phosphoglycerate mutase (PGAM) activity and isozyme transition in rat skeletal and cardiac muscles. METHODS: The effects of T3 on PGAM types B and M subunit expression in rat muscle during development are reported. RESULTS: T3 administration during the first 21 days of rat life more than doubles type M PGAM mRNA levels, but produces minor effects on type B PGAM mRNA levels. The antihormone propylthiouracil (PTU) slightly decreases both type B and M mRNA levels, but this decrease is not statistically significant. CONCLUSION: Thyroid hormone influences PGAM mRNA isozyme levels differently and increases type M mRNA.


Assuntos
Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Coração/crescimento & desenvolvimento , Músculo Esquelético/enzimologia , Músculo Esquelético/crescimento & desenvolvimento , Músculos/enzimologia , Miocárdio/enzimologia , Fosfoglicerato Mutase/biossíntese , RNA Mensageiro/biossíntese , Hormônios Tireóideos/farmacologia , Animais , Animais Recém-Nascidos , Antitireóideos/farmacologia , Northern Blotting , Densitometria , Coração/efeitos dos fármacos , Isoenzimas/biossíntese , Isoenzimas/genética , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculos/efeitos dos fármacos , Fosfoglicerato Mutase/genética , Propiltiouracila/farmacologia , Ratos , Ratos Sprague-Dawley , Tri-Iodotironina/farmacologia
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