High Precision Detection of Change in Intermediate Range Order of Amorphous Zirconia-Doped Tantala Thin Films Due to Annealing.

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.

Hypoglycaemia represents a clinically significant manifestation of PIK3CA- and CCND2-associated segmental overgrowth.

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.

Silicon-Based Optical Mirror Coatings for Ultrahigh Precision Metrology and Sensing.

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}).

Lifestyle and youthful looks.

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.

Smoking initiation is followed by the early acquisition of epigenetic change in cervical epithelium: a longitudinal study.

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.

A role for human endogenous retrovirus-K (HML-2) in rheumatoid arthritis: investigating mechanisms of pathogenesis.

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.

Ageing appearance in China: biophysical profile of facial skin and its relationship to perceived age.

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.

Inflammation and tissue repair markers distinguish the nodular sclerosis and mixed cellularity subtypes of classical Hodgkin's lymphoma.

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.

Likelihood of persistent GH deficiency into late adolescence: relationship to the presence of an ectopic or normally sited posterior pituitary gland.

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.

Correction: S1PR1 drives a feedforward signalling loop to regulate BATF3 and the transcriptional programme of Hodgkin lymphoma cells.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Associations with multiple pituitary hormone deficiency in patients with an ectopic posterior pituitary gland.

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.

S1PR1 drives a feedforward signalling loop to regulate BATF3 and the transcriptional programme of Hodgkin lymphoma cells.

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.

Diagnosis of growth hormone deficiency in the paediatric and transitional age.

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.

Controversies in the diagnosis and management of growth hormone deficiency in childhood and adolescence.

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.

Variation in the frequency of Epstein-Barr virus-associated Hodgkin's disease with age.

A number of studies in developed countries have reported variation in the frequency of Epstein-Barr virus (EBV)-associated Hodgkin's disease (HD) with age. A 'three disease' model for HD that incorporates the EBV association, histological subtype of HD and age has recently been proposed. In this model, Hodgkin's disease of childhood and older adults is commonly EBV-associated and of mixed cellularity type, whereas young adult HD is generally not EBV-associated and is usually characterised by nodular sclerosis disease. A case series of HD diagnosed in the West Midlands between 1981 and 1997, inclusive, was used to investigate the applicability of the 'three disease' model. In situ hybridisation for the EBV early RNAs (EBERs) was used to determine the presence of EBV in the malignant Hodgkin/Reed-Sternberg cells. In contrast to the 'three disease' model, nodular sclerosis was the predominant subtype in each of the age groups within the case series. In addition, overall there was little variation in EBV-positive rates across the age ranges examined. However, when females were analysed separately, older women (45+ years) were significantly more likely to have EBV-positive disease than their younger counterparts (<45 years). In summary our results do not generally support the 'three disease' model.

60 YEARS OF NEUROENDOCRINOLOGY: The hypothalamo-GH axis: the past 60 years.

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.

Enhancement of thyrotropin-stimulated iodide organification in porcine thyroid cells after protein kinase-C inhibition.

We and others have previously shown that 12-O-tetracanoylphorbol-13-acetate (TPA), a protein kinase-C (PKC) activator, inhibits TSH-stimulated iodide organification in porcine thyroid cells. However, TPA action may be independent of PKC. To further explore the role of PKC in the regulation of differentiated thyroid function, we studied the effects of the PKC inhibitors 1-O-hexadecyl-2-O-methylglycerol (AMG-C16), 1-(5-isoquinolinesulfonyl)2-methylpiperazine (H7), and staurosporine on TSH-stimulated iodide organification in porcine thyroid cells in the presence and absence of TPA. AMG-C16 increased basal iodide organification in concentrations ranging from 15-240 microM (P < 0.01, by analysis of variance). Such stimulation by AMG-C16 (30-120 microM) persisted in the presence of submaximal (10 microU) and maximal (1 mU) concentrations of TSH. However, in the presence of TPA (> 10 nM), the effects of AMG-C16 were abolished. H7 (50 microM) and staurosporine (100 nM) also enhanced TSH-stimulated iodide organification. In the presence of staurosporine and TPA, no inhibition of TSH-stimulated iodide organification was observed. However, H7 could not reverse the effects of TPA. In summary, these studies indicate that in porcine thyroid cells, three distinct PKC inhibitors all enhanced TSH-stimulated iodide organification and that staurosporine reversed the effects of TPA on TSH-stimulated iodide organification. These findings are consistent with the concept that PKC acts as an endogenous negative modulator of iodide organification in vitro.

Protein kinase C activators modulate differentiated thyroid function in vitro.

Exposure of porcine thyroid cells to the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) leads to inhibition of differentiated thyroid function. We investigated whether this effect is mediated via protein kinase C activation. TPA, phorbol 12,13-didecanoate and phorbol 12,13-dibutyrate inhibited TSH-stimulated iodine organification in porcine thyroid cells by 98, 96 and 45%, respectively. Non-tumour promoting phorbol esters had no effect. The diacylglycerol analogue, sn-1,2-dioctanoylglycerol had similar but quantitatively less activity than TPA. Dibutyryl cAMP could not reverse any inhibition noted. Under conditions that caused significant inhibition of differentiated function, TPA caused translocation of thyroidal protein kinase C from the cytosol to its membrane-bound form. These data provide evidence that the mechanism of phorbol action on thyroid function in vitro includes activation of protein kinase C.

Translocation of protein kinase C in porcine thyroid cells following exposure to thyrotropin.

We have previously shown that protein kinase C activators modulate differentiated thyroid function in vitro; however, how protein kinase C may be activated physiologically is unknown. The present studies were undertaken in order to determine whether TSH could activate protein kinase C in vitro. Following exposure of porcine thyroid cells to TSH, translocation of protein kinase C from the cytosol to its membrane-bound form was observed. Maximal translocation occurred at the lowest TSH concentration able to trigger this response (10 mU/ml) but persisted at higher concentrations (20-100 mU/ml). Time-course studies revealed that translocation of protein kinase C was seen only after 40 min. TSH could also produce a similar translocation in human neutrophils (known to have TSH receptors). In thyroid cells pre-treated with TSH, modulation of phorbol-mediated protein kinase C translocation was noted. These results indicate that TSH causes the translocation of protein kinase C in porcine thyroid cells (and possibly other TSH receptor-containing cells) and therefore may regulate the action of protein kinase C on differentiated thyroid function.

The Role of the Epstein-Barr virus in human disease.

EBV is a B lymphotropic virus that is associated with a range of human malignancies. Although for many of these tumours the association has long been established, unraveling the precise role of EBV in disease pathogenesis has been more difficult. This review summarizes current knowledge concerning the association between EBV and human cancers and illustrates how an increasing appreciation of patterns of latent gene expression and latent gene function in different cell environments is already helping towards a better understanding of both the natural history of infection in normal individuals and how EBV contributes to malignant transformation. Finally, therapeutic strategies that target EBV in tumours are discussed.