Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 88
Filtrar
1.
Phys Rev Lett ; 123(4): 045501, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31491265

RESUMO

Understanding the local atomic order in amorphous thin film coatings and how it relates to macroscopic performance factors, such as mechanical loss, provides an important path towards enabling the accelerated discovery and development of improved coatings. High precision x-ray scattering measurements of thin films of amorphous zirconia-doped tantala (ZrO_{2}-Ta_{2}O_{5}) show systematic changes in intermediate range order (IRO) as a function of postdeposition heat treatment (annealing). Atomic modeling captures and explains these changes, and shows that the material has building blocks of metal-centered polyhedra and the effect of annealing is to alter the connections between the polyhedra. The observed changes in IRO are associated with a shift in the ratio of corner-sharing to edge-sharing polyhedra. These changes correlate with changes in mechanical loss upon annealing, and suggest that the mechanical loss can be reduced by developing a material with a designed ratio of corner-sharing to edge-sharing polyhedra.

3.
Phys Rev Lett ; 120(26): 263602, 2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-30004721

RESUMO

Thermal noise of highly reflective mirror coatings is a major limit to the sensitivity of many precision laser experiments with strict requirements such as low optical absorption. Here, we investigate amorphous silicon and silicon nitride as an alternative to the currently used combination of coating materials, silica, and tantala. We demonstrate an improvement by a factor of ≈55 with respect to the lowest so far reported optical absorption of amorphous silicon at near-infrared wavelengths. This reduction was achieved via a combination of heat treatment, final operation at low temperature, and a wavelength of 2 µm instead of the more commonly used 1550 nm. Our silicon-based coating offers a factor of 12 thermal noise reduction compared to the performance possible with silica and tantala at 20 K. In gravitational-wave detectors, a noise reduction by a factor of 12 corresponds to an increase in the average detection rate by three orders of magnitude (≈12^{3}).

4.
Clin Genet ; 93(3): 687-692, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28941273

RESUMO

The PI3K-AKT signalling cascade has a highly conserved role in a variety of processes including cell growth and glucose homoeostasis. Variants affecting this pathway can lead to one of several segmental overgrowth disorders. These conditions are genetically heterogeneous and require tailored, multidisciplinary involvement throughout life. Hypoglycaemia is common in other overgrowth syndromes but has been described only sporadically in association with PIK3CA and CCND2 variants. We report a cohort of 6 children with megalencephaly-capillary malformation (MCAP) and megalencephaly-polydactyly-polymicrogyria-hydrocephalus (MPPH) syndromes who developed clinically significant hypoglycaemia. Based on our findings, we suggest that segmental overgrowth patients should be screened for low blood glucose levels during childhood and there should be early specialist endocrine review in any children who develop hypoglycaemia.


Assuntos
Classe I de Fosfatidilinositol 3-Quinases/genética , Ciclina D2/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Hipoglicemia/diagnóstico , Hipoglicemia/genética , Fenótipo , Adolescente , Alelos , Criança , Pré-Escolar , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Ciclina D2/metabolismo , Feminino , Estudos de Associação Genética/métodos , Variação Genética , Genótipo , Humanos , Lactente , Masculino , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Adulto Jovem
5.
Leukemia ; 32(1): 214-223, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28878352

RESUMO

The Hodgkin/Reed-Sternberg cells of classical Hodgkin lymphoma (HL) are characterised by the aberrant activation of multiple signalling pathways. Here we show that a subset of HL displays altered expression of sphingosine-1-phosphate (S1P) receptors (S1PR)s. S1P activates phosphatidylinositide 3-kinase (PI3-K) in these cells that is mediated by the increased expression of S1PR1 and the decreased expression of S1PR2. We also showed that genes regulated by the PI3-K signalling pathway in HL cell lines significantly overlap with the transcriptional programme of primary HRS cells. Genes upregulated by the PI3-K pathway included the basic leucine zipper transcription factor, ATF-like 3 (BATF3), which is normally associated with the development of dendritic cells. Immunohistochemistry confirmed that BATF3 was expressed in HRS cells of most HL cases. In contrast, in normal lymphoid tissues, BATF3 expression was confined to a small fraction of CD30-positive immunoblasts. Knockdown of BATF3 in HL cell lines revealed that BATF3 contributed to the transcriptional programme of primary HRS cells, including the upregulation of S1PR1. Our data suggest that disruption of this potentially oncogenic feedforward S1P signalling loop could provide novel therapeutic opportunities for patients with HL.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/genética , Doença de Hodgkin/genética , Receptores de Lisoesfingolipídeo/genética , Transdução de Sinais/genética , Transcrição Gênica/genética , Linhagem Celular , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Células HEK293 , Humanos , Fosfatidilinositol 3-Quinases/genética , Receptores de Esfingosina-1-Fosfato , Células Tumorais Cultivadas
6.
Best Pract Res Clin Endocrinol Metab ; 30(6): 737-747, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27974187

RESUMO

Growth hormone deficiency is a rare cause of childhood short stature, but one for which treatment exists in the form of recombinant human growth hormone. A diagnosis of growth hormone deficiency is made based on auxology, biochemistry and imaging. Although no diagnostic gold standard exists, growth hormone provocation tests are considered the mainstay of diagnostic investigations. However, these must be interpreted with caution in view of issues with variability and reproducibility, as well as the limited evidence-base for cut-off values used to distinguish growth hormone deficient and non-growth hormone deficient subjects. In addition, nutritional and pubertal status can affect results, with no consensus on the role of priming with sex steroid hormones. Difficulties with assays exist both for growth hormone as well as insulin-like growth factor-1. Pituitary magnetic resonance imaging is a useful diagnostic, and possibly prognostic, aid. Although genetic testing is not routine, the discovery of more relevant mutations makes it an increasingly important investigation. Children with growth hormone deficiency are retested biochemically on completion of growth, to assess whether they remain so into adulthood.


Assuntos
Nanismo Hipofisário/diagnóstico , Adolescente , Criança , Nanismo Hipofisário/sangue , Nanismo Hipofisário/diagnóstico por imagem , Nanismo Hipofisário/genética , Testes Genéticos , Hormônio do Crescimento/sangue , Hormônio do Crescimento/deficiência , Hormônio do Crescimento/genética , Humanos , Imageamento por Ressonância Magnética
7.
Arch Dis Child ; 101(1): 96-100, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26153506

RESUMO

Growth hormone deficiency (GHD) is a rare but important cause of short stature in childhood with a prevalence of 1 in 4000. The diagnosis is currently based on an assessment of auxology along with supporting evidence from biochemical and neuroradiological studies. There are significant controversies in the diagnosis and management of GHD. Growth hormone (GH) stimulation tests continue to play a key role in GHD diagnosis but the measured GH concentration can vary significantly with stimulation test and GH assay used, creating difficulties for diagnostic accuracy. Such issues along with the use of adjunct biochemical markers such as IGF-I and IGFBP-3 for the diagnosis of GHD, will be discussed in this review. Additionally, the treatment of GHD remains a source of much debate; there is no consensus on the best mechanism for determining the starting dose of GH in patients with GHD. Weight and prediction based models will be discussed along with different mechanisms for dose adjustment during treatment (auxology or IGF-I targeting approaches). At the end of growth and childhood treatment, many subjects diagnosed with isolated GHD re-test normal. It is not clear if this represents a form of transient GHD or a false positive diagnosis during childhood. Given the difficulties inherent in the diagnosis of GHD, an early reassessment of the diagnosis in those who respond poorly to GH is to be recommended.


Assuntos
Transtornos do Crescimento/diagnóstico , Hormônio do Crescimento Humano/deficiência , Adolescente , Criança , Gerenciamento Clínico , Esquema de Medicação , Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento Humano/administração & dosagem , Hormônio do Crescimento Humano/sangue , Humanos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Guias de Prática Clínica como Assunto , Reprodutibilidade dos Testes , Falha de Tratamento
8.
J Endocrinol ; 226(2): T123-40, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26040485

RESUMO

At the time of the publication of Geoffrey Harris's monograph on 'Neural control of the pituitary gland' 60 years ago, the pituitary was recognised to produce a growth factor, and extracts administered to children with hypopituitarism could accelerate growth. Since then our understanding of the neuroendocrinology of the GH axis has included identification of the key central components of the GH axis: GH-releasing hormone and somatostatin (SST) in the 1970s and 1980s and ghrelin in the 1990s. Characterisation of the physiological control of the axis was significantly advanced by frequent blood sampling studies in the 1980s and 1990s; the pulsatile pattern of GH secretion and the factors that influenced the frequency and amplitude of the pulses have been defined. Over the same time, spontaneously occurring and targeted mutations in the GH axis in rodents combined with the recognition of genetic causes of familial hypopituitarism demonstrated the key factors controlling pituitary development. As the understanding of the control of GH secretion advanced, developments of treatments for GH axis disorders have evolved. Administration of pituitary-derived human GH was followed by the introduction of recombinant human GH in the 1980s, and, more recently, by long-acting GH preparations. For GH excess disorders, dopamine agonists were used first followed by SST analogues, and in 2005 the GH receptor blocker pegvisomant was introduced. This review will cover the evolution of these discoveries and build a picture of our current understanding of the hypothalamo-GH axis.


Assuntos
Hormônio do Crescimento/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Hipófise/metabolismo , Animais , Humanos
9.
Br J Dermatol ; 172(5): 1338-45, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25627783

RESUMO

BACKGROUND: Lifestyle has been proven to have a dramatic effect on the risk of age-related diseases. The association of lifestyle and facial ageing has been less well studied. OBJECTIVES: To identify lifestyle factors that associate with perceived facial age in white north European men and women. METHODS: Lifestyle, facial wrinkling and perceived facial age were studied in two cross-sectional studies consisting of 318 Dutch men and 329 women aged 45-75 years who were part of the Leiden Longevity Study, and 162 English women aged 45-75 years who were nonsmokers. RESULTS: In Dutch men, smoking, having skin that went red in the sun, being outside in the sun most of the summer, sunbed use, wearing false teeth and not flossing teeth were all significantly associated (P < 0·05) with a total 9·3-year higher perceived facial age in a multivariate model adjusting for chronological age. In Dutch women, smoking, sunbathing, sunbed use, few remaining teeth and a low body mass index (BMI) were associated with a total 10·9-year higher perceived facial age. In English women, cleaning teeth only once a day, wearing false teeth, irregular skin moisturization and having skin that went red in the sun were associated with a total 9·1-year higher perceived facial age. Smoking and sunbed use were associated more strongly with wrinkling in women than in men. BMI, sun exposure and skincare were associated predominantly with perceived facial age via wrinkling, whereas oral care was associated via other facial features. CONCLUSIONS: Although associative in nature, these results support the notion that lifestyle factors can have long-term beneficial effects on youthful looks.


Assuntos
Imagem Corporal/psicologia , Face , Estilo de Vida , Envelhecimento da Pele/etnologia , Idoso , Estudos Transversais , Inglaterra/etnologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos/etnologia , Percepção , Caracteres Sexuais , População Branca/etnologia
10.
Endocr Connect ; 2(4): 225-35, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24148222

RESUMO

3-M syndrome is an autosomal recessive disorder characterised by pre- and post-natal growth restriction, facial dysmorphism, normal intelligence and radiological features (slender long bones and tall vertebral bodies). It is known to be caused by mutations in the genes encoding cullin 7, obscurin-like 1 and coiled-coil domain containing 8. The mechanisms through which mutations in these genes impair growth are unclear. The aim of this study was to identify novel pathways involved in the growth impairment in 3-M syndrome. RNA was extracted from fibroblast cell lines derived from four 3-M syndrome patients and three control subjects, hybridised to Affymetrix HU 133 plus 2.0 arrays with quantitative real-time PCR used to confirm changes found on microarray. IGF-II protein levels in conditioned cell culture media were measured by ELISA. Of the top 10 downregulated probesets, three represented IGF2 while H19 was identified as the 23rd most upregulated probeset. QRT-PCR confirmed upregulation of H19 (P<0.001) and downregulation of IGF2 (P<0.001). Levels of IGF-II secreted into conditioned cell culture medium were higher for control fibroblasts than those for 3-M fibroblasts (10.2±2.9 vs 0.6±0.9 ng/ml, P<0.01). 3-M syndrome is associated with a gene expression profile of reduced IGF2 expression and increased H19 expression similar to that found in Silver-Russell syndrome. Loss of autocrine IGF-II in the growth plate may be associated with the short stature seen in children with 3-M syndrome.

11.
J Mol Endocrinol ; 49(3): 267-75, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23018678

RESUMO

3-M syndrome is a primordial growth disorder caused by mutations in CUL7, OBSL1 or CCDC8. 3-M patients typically have a modest response to GH treatment, but the mechanism is unknown. Our aim was to screen 13 clinically identified 3-M families for mutations, define the status of the GH-IGF axis in 3-M children and using fibroblast cell lines assess signalling responses to GH or IGF1. Eleven CUL7, three OBSL1 and one CCDC8 mutations in nine, three and one families respectively were identified, those with CUL7 mutations being significantly shorter than those with OBSL1 or CCDC8 mutations. The majority of 3-M patients tested had normal peak serum GH and normal/low IGF1. While the generation of IGF binding proteins by 3-M cells was dysregulated, activation of STAT5b and MAPK in response to GH was normal in CUL7(-/-) cells but reduced in OBSL1(-/-) and CCDC8(-/-) cells compared with controls. Activation of AKT to IGF1 was reduced in CUL7(-/-) and OBSL1(-/-) cells at 5 min post-stimulation but normal in CCDC8(-/-) cells. The prevalence of 3-M mutations was 69% CUL7, 23% OBSL1 and 8% CCDC8. The GH-IGF axis evaluation could reflect a degree of GH resistance and/or IGF1 resistance. This is consistent with the signalling data in which the CUL7(-/-) cells showed impaired IGF1 signalling, CCDC8(-/-) cells showed impaired GH signalling and the OBSL1(-/-) cells showed impairment in both pathways. Dysregulation of the GH-IGF-IGF binding protein axis is a feature of 3-M syndrome.


Assuntos
Proteínas de Transporte/genética , Proteínas Culina/genética , Proteínas do Citoesqueleto/genética , Nanismo/genética , Nanismo/metabolismo , Hipotonia Muscular/genética , Hipotonia Muscular/metabolismo , Criança , Pré-Escolar , Nanismo/sangue , Nanismo/patologia , Feminino , Hormônio do Crescimento/sangue , Humanos , Lactente , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Hipotonia Muscular/sangue , Hipotonia Muscular/patologia , Mutação , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Coluna Vertebral/anormalidades , Coluna Vertebral/metabolismo , Coluna Vertebral/patologia
12.
Br J Cancer ; 104(9): 1500-4, 2011 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-21487403

RESUMO

BACKGROUND: To prove a causal link between an epigenetic change and an environmental or behavioural risk factor for a given disease, it is first necessary to show that the onset of exposure precedes the first detection of that epigenetic change in subjects who are still free of disease. METHODS: Towards this end, a cohort of women aged 15-19 years, recruited soon after they first had sexual intercourse, were used to provide sequential observations on the relationship between cigarette smoking and the detection in cervical cytological samples of methylated forms of CDKN2A (p16) using nested methylation-specific polymerase chain reaction. RESULTS: Among women who remained cytologically normal and who tested negative for human papillomavirus DNA in cervical smears during follow-up, those who first started to smoke during follow-up had an increased risk of acquiring CDKN2A methylation compared with never-smokers (odds ratio=3.67; 95% confidence interval 1.09-12.33; P=0.04). CONCLUSION: Smoking initiation is associated with the appearance of methylated forms of CDKN2A.


Assuntos
Colo do Útero/metabolismo , Inibidor p16 de Quinase Dependente de Ciclina/genética , Metilação de DNA , Epigênese Genética , Fumar/efeitos adversos , Adolescente , Alphapapillomavirus , Estudos de Coortes , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Feminino , Humanos , Modelos Logísticos , Estudos Longitudinais , Razão de Chances , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase/métodos , Fatores de Risco , Fumar/genética , Inquéritos e Questionários , Infecções Tumorais por Vírus/complicações , Infecções Tumorais por Vírus/patologia , Infecções Tumorais por Vírus/virologia , Neoplasias do Colo do Útero/etiologia , Esfregaço Vaginal , Adulto Jovem , Displasia do Colo do Útero/etiologia
13.
Eur J Endocrinol ; 164(4): 521-7, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21296922

RESUMO

INTRODUCTION: Leptin deficiency caused by mutations within the leptin gene (LEP) results in severe early onset obesity, hypogonadism, pubertal delay and immune system abnormalities. Constitutional delay in growth and puberty (CDGP) is a common condition seen in paediatric clinics, in which children present with delayed growth and puberty but usually also have a slim body habitus. We hypothesized that LEP variants may play a role in the phenotype seen in CDGP. AIM: To screen a group of children with CDGP for pathogenic sequence variants in LEP. PATIENTS AND METHODS: Denaturing HPLC was used to screen for LEP sequence variants in DNA samples from 78 children with CDGP (predominantly white males) and 112 control subjects. DNA fragments with a WAVE pattern deviant from wild type were directly sequenced. A STAT3 luciferase reporter assay in human embryonic kidney (HEK293) cells transiently transfected with the leptin receptor was used to test activity of mutant leptin. RESULTS: One child with CDGP was identified to be heterozygous for a novel missense variant (c.68C>G), which results in a proline to arginine substitution (p.P23R). This sequence variant was not identified in any of the other control subjects, but was identified in his mother who shared a similar phenotype of slim body habitus, reduced appetite and pubertal delay (menarche aged 15 years). The leptin variant showed similar stability in serum compared with wild type and did not demonstrate increased activity in an in vitro reporter gene assay. CONCLUSIONS: This is the first report of a sequence variant within the LEP gene associated with reduced body mass index rather than obesity. We hypothesize that this variant has increased bioactivity in vivo.


Assuntos
Apetite/genética , Leptina/genética , Puberdade Tardia/etiologia , Puberdade Tardia/genética , Adolescente , Índice de Massa Corporal , Feminino , Humanos , Leptina/sangue , Masculino , Linhagem , Puberdade Tardia/sangue
14.
Oncogene ; 30(17): 2037-43, 2011 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-21242977

RESUMO

There is now evidence for both increased and decreased activity of the enzymes controlling the methylation of lysine 27 on histone 3 (H3K27) in cancer. One of these enzymes, KDM6B formally known as JMJD3, a histone demethylase, which removes the trimethyl mark from H3K27, is required for the lineage commitment and terminal differentiation of neural stem cells and of keratinocytes. Our results suggest that KDM6B may also have a role in antigen-driven B-cell differentiation. KDM6B expression increases in B-cell subsets with increasing stage of differentiation, and gene expression profiling shows that KDM6B transcriptional targets in germinal centre B (GC B) cells are significantly enriched for those differentially expressed during memory and plasma cell differentiation. Our results also suggest that aberrant expression of KDM6B may contribute to the pathogenesis of Hodgkin's Lymphoma (HL), an Epstein-Barr virus (EBV) associated malignancy. KDM6B is over-expressed in primary HL and induced by the EBV oncogene, latent membrane protein (LMP1) in GC B cells, the presumptive progenitors of HL. Consistent with these observations, we found that KDM6B transcriptional targets in GC B cells are enriched for genes differentially expressed in HL, and that KDM6B depletion can restore the tri-methylation of H3K27 on these genes.


Assuntos
Regulação Neoplásica da Expressão Gênica , Herpesvirus Humano 4/fisiologia , Doença de Hodgkin/genética , Doença de Hodgkin/virologia , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Subpopulações de Linfócitos B/citologia , Subpopulações de Linfócitos B/metabolismo , Diferenciação Celular , Linhagem Celular Tumoral , Transformação Celular Viral/genética , Herpesvirus Humano 4/genética , Doença de Hodgkin/enzimologia , Doença de Hodgkin/patologia , Humanos , Transcrição Gênica , Regulação para Cima , Proteínas da Matriz Viral/genética
15.
Clin Exp Immunol ; 160(3): 340-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20345981

RESUMO

Human endogenous retroviruses (HERVs) are remnants of ancient retroviral infections within the human genome. These molecular fossils draw parallels with present-day exogenous retroviruses and have been linked previously with immunopathology within rheumatoid arthritis (RA). Mechanisms of pathogenesis for HERV-K in RA such as molecular mimicry were investigated. To clarify a role for HERVs in RA, potential autoantigens implicated in autoimmunity were scanned for sequence identity with retroviral epitopes. Short retroviral peptides modelling shared epitopes were synthesized, to survey anti-serum of RA patients and disease controls. A novel real-time polymerase chain reaction (PCR) assay was also developed to quantify accurately levels of HERV-K (HML-2) gag expression, relative to normalized housekeeping gene expression. Both serological and molecular assays showed significant increases in HERV-K (HML-2) gag activity in RA patients, compared to disease controls. The real-time PCR assay identified significant up-regulation in HERV-K mRNA levels in RA patients compared to inflammatory and healthy controls. Exogenous viral protein expression and proinflammatory cytokines were also shown to exert modulatory effects over HERV-K (HML-2) transcription. From our data, it can be concluded that RA patients exhibited significantly elevated levels of HERV-K (HML-2) gag activity compared to controls. Additional factors influencing HERV activity within the synovium were also identified. The significant variation in RA patients, both serologically and transcriptionally, may be an indication that RA is an umbrella term for a number of separate disease entities, of which particular HERV polymorphisms may play a role in development.


Assuntos
Artrite Reumatoide/metabolismo , Autoantígenos/metabolismo , Retrovirus Endógenos/metabolismo , Regulação Viral da Expressão Gênica/imunologia , Produtos do Gene gag/biossíntese , Mimetismo Molecular , Peptídeos/metabolismo , Adulto , Idoso , Artrite Reumatoide/imunologia , Artrite Reumatoide/patologia , Artrite Reumatoide/virologia , Autoantígenos/imunologia , Retrovirus Endógenos/imunologia , Epitopos/imunologia , Epitopos/metabolismo , Feminino , Produtos do Gene gag/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeos/imunologia , Polimorfismo Genético/imunologia , RNA Mensageiro/biossíntese , RNA Mensageiro/imunologia , RNA Viral/biossíntese , RNA Viral/imunologia , Membrana Sinovial/imunologia , Membrana Sinovial/metabolismo , Membrana Sinovial/virologia , Transcrição Gênica/imunologia
16.
J Eur Acad Dermatol Venereol ; 24(3): 341-8, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19758262

RESUMO

BACKGROUND: Perceived age is important to women and is a primary driver for topical product use and facial cosmetic surgery. Changes in facial features and biophysical skin parameters with chronological age and their associations with perceived age have not been described in Asian populations. OBJECTIVE: To investigate the relationship between biophysical properties of the skin, visual features of skin ageing and perceived facial age in Chinese women. METHODS: Facial photographs were collected of 250 Chinese women, aged 25-70 years in Shanghai, China. The perceived facial age was determined and related to the chronological age for each participant and to a range of visual assessments of skin appearance and objective biophysical measurements of the skin. The profile of changes in these parameters with age was investigated together with the differences in those parameters for women judged to look younger than their chronological age and those judged to look older than their chronological age. RESULTS: Large discrepancies in perceived age (up to 29 years) were found in women of the same chronological age. Each objective skin measure and visual assessment parameter had a stronger correlation with perceived age than with chronological age. The strongest relationships to perceived age were for wrinkles and hyperpigmentation. Skin colour, hydration and trans-epidermal water loss (TEWL) had weaker associations with perceived age. Women judged to look older than their chronological age had significantly higher scores than those judged to look younger for coarse wrinkles and hyperpigmentation across all age groups. The appearance differences between these groups were evident in composite facial images of the same average chronological age. CONCLUSIONS: We have identified the skin attributes which differ with perceived age in Chinese women. Perceived age is a better measure of the biological age of facial skin than is chronological age in this population.


Assuntos
Envelhecimento/fisiologia , Face/fisiologia , Autoimagem , Envelhecimento da Pele/fisiologia , Adulto , Idoso , China , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade
17.
Br J Cancer ; 101(8): 1393-401, 2009 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-19773754

RESUMO

BACKGROUND: Classical Hodgkin's lymphoma (cHL), although a malignant disease, has many features in common with an inflammatory condition. The aim of this study was to establish the molecular characteristics of the two most common cHL subtypes, nodular sclerosis (NS) and mixed cellularity (MC), based on molecular profiling and immunohistochemistry, with special reference to the inflammatory microenvironment. METHODS: We analysed 44 gene expression profiles of cHL whole tumour tissues, 25 cases of NS and 19 cases of MC, using Affymetrix chip technology and immunohistochemistry. RESULTS: In the NS subtype, 152 genes showed a significantly higher expression, including genes involved in extracellular matrix (ECM) remodelling and ECM deposition similar to wound healing. Among these were SPARC, CTSK and COLI. Immunohistochemistry revealed that the NS-related genes were mainly expressed by macrophages and fibroblasts. Fifty-three genes had a higher expression in the MC subtype, including several inflammation-related genes, such as C1Qalpha, C1Qbeta and CXCL9. In MC tissues, the C1Q subunits were mainly expressed by infiltrating macrophages. CONCLUSIONS AND INTERPRETATIONS: We suggest that the identified subtype-specific genes could reflect different phases of wound healing. Our study underlines the potential function of infiltrating macrophages in shaping the cHL tumour microenvironment.


Assuntos
Perfilação da Expressão Gênica , Doença de Hodgkin/classificação , Doença de Hodgkin/patologia , Inflamação/patologia , Cicatrização , Adolescente , Adulto , Idoso , Biomarcadores , Matriz Extracelular/metabolismo , Feminino , Fibrose , Doença de Hodgkin/genética , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade
18.
Clin Endocrinol (Oxf) ; 71(2): 215-9, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19226266

RESUMO

OBJECTIVES: The presence of an ectopic posterior pituitary gland (EPP) in childhood is associated with isolated GH deficiency (IGHD) and multiple pituitary hormone deficiency. GHD in late adolescence has been defined as a peak GH level <5 microg/l. The aim of this study was to identify the likelihood of persistent GHD in late adolescence in patients with an EPP compared with those with a normally sited posterior pituitary (NPP). METHODS: In 18 patients with an EPP and 15 patients with an NPP, clinical, biochemical and radiographic data were collected. RESULTS: In the EPP vs. the NPP group, the change in peak GH levels at the end of growth was less (+0.4[95% confidence interval (CI) - 0.8 to 2.7] vs. +4.1[95%CI + 0.4 to +10.5] microg/l, P-value for ancova = 0.03, after adjustment for age and sex). Using a peak GH level of <5 microg/l as a cut-off for GHD, 66% of EPP subjects compared with 40% of NPP subjects had GHD (P = 0.3). Hundred per cent of EPP subjects had a peak GH level on retesting <10 microg/l, compared with 40% of NPP subjects (P < 0.001). CONCLUSION: It is important to document GH status at the end of growth, even if there is a structural abnormality of the hypothalamic-pituitary axis. The presence of an EPP compared to an NPP increases the likelihood of persistent GHD by 26%. As all EPP patients had a peak GH level of <10 microg/l, the cut-off for persistent GHD in late adolescence may need to be revised.


Assuntos
Desenvolvimento do Adolescente , Hormônio do Crescimento Humano/deficiência , Neuro-Hipófise/anormalidades , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Masculino , Neuro-Hipófise/diagnóstico por imagem , Radiografia , Adulto Jovem
19.
J Pathol ; 216(1): 83-92, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18566961

RESUMO

Although the latent membrane protein-1 (LMP1) of the Epstein-Barr virus (EBV) is believed to be important for the transformation of germinal centre (GC) B cells, the precise contribution of this viral oncogene to lymphoma development is poorly understood. In this study, we used a non-viral vector-based method to express LMP1 in primary human GC B cells. Gene expression profiling revealed that LMP1 induced in GC B cells transcriptional changes characteristic of Hodgkin's lymphoma cell lines. Strikingly, LMP1 down-regulated the expression of B-cell-specific genes including B-cell receptor components such as CD79A, CD79B, CD19, CD20, CD22, and BLNK. LMP1 also induced the expression of ID2, a negative regulator of B-cell differentiation. Our data suggest that in EBV-positive cases, LMP1 is likely to be a major contributor to the altered transcriptional pattern characteristic of Hodgkin/Reed-Sternberg cells, including the loss of B-cell identity.


Assuntos
Linfócitos B/metabolismo , Doença de Hodgkin/genética , Células de Reed-Sternberg/metabolismo , Proteínas da Matriz Viral/fisiologia , Linfócitos B/virologia , Doença de Hodgkin/virologia , Humanos , Fenótipo , Células de Reed-Sternberg/virologia , Análise Serial de Tecidos/métodos , Células Tumorais Cultivadas
20.
Clin Endocrinol (Oxf) ; 69(4): 597-602, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18331606

RESUMO

INTRODUCTION: The presence of an ectopic posterior pituitary gland (EPP) on magnetic resonance imaging (MRI) is associated with hypopituitarism with one or more hormone deficiencies. We aimed to identify risk factors for having multiple pituitary hormone deficiency (MPHD) compared to isolated growth hormone deficiency (IGHD) in patients with an EPP. METHODS: In 67 patients (45 male) with an EPP on MRI, the site (hypothalamic vs. stalk) and surface area (SA) [ x (maximum diameter/2) x (maximum height/2), mm(2)] of the EPP were recorded and compared in patients with IGHD and MPHD in relation to clinical characteristics. RESULTS: In MPHD (n = 32) compared to IGHD (n = 35) patients: age of presentation was younger (1.4 [0.1-10.7]vs. 4.0 [0.1-11.3] years, P = 0.005), major incidents during pregnancy were increased (47%vs. 20%, P = 0.02) as were admissions to a neonatal intensive care unit (NICU) (60%vs. 26%, P = 0.04), whilst EPP SA was lower (12.3 [2.4-34.6]vs. 25.7 [6.9-48.2] mm(2), P < 0.001). In patients with a hypothalamic (n = 56) compared to a stalk sited EPP (n = 11): prevalence of MPHD was greater (55%vs. 9%,P = 0.05) and EPP surface area was smaller (17.3 [2.4-48.2]vs. 25.3 [11.8-38.5] mm(2), P < 0.001). In regression analysis, after adjusting for age, presence of MPHD was associated with: major incidents during pregnancy (RR 6.8 [95%CI 1.2-37.7]), hypothalamic EPP site (RR 10.9 [1.0-123.9]) and small EPP SA (RR 2.5 [1.0-5.0] for tertiles of SA). CONCLUSION: In patients with an EPP, adverse antenatal events, size (small) and position (hypothalamic) of the posterior pituitary gland on MRI were associated with MPHD. These findings suggest that adverse factors during pregnancy may be important for the development of an EPP.


Assuntos
Coristoma/epidemiologia , Hipopituitarismo/epidemiologia , Doenças Hipotalâmicas/epidemiologia , Neuro-Hipófise , Hormônios Hipofisários/deficiência , Criança , Pré-Escolar , Coristoma/complicações , Estudos de Coortes , Feminino , Seguimentos , Humanos , Hipopituitarismo/complicações , Doenças Hipotalâmicas/complicações , Lactente , Recém-Nascido , Masculino , Gravidez , Prevalência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...