Towards a mechanistic understanding of carbon stabilization in manganese oxides

Minerals stabilize organic carbon (OC) in sediments, thereby directly affecting global climate at multiple scales, but how they do it is far from understood. Here we show that manganese oxide (Mn oxide) in a water treatment works filter bed traps dissolved OC as coatings build up in layers around clean sand grains at 3%w/wC. Using spectroscopic and thermogravimetric methods, we identify two main OC fractions. One is thermally refractory (>550 °C) and the other is thermally more labile (<550 °C). We postulate that the thermal stability of the trapped OC is due to carboxylate groups within it bonding to Mn oxide surfaces coupled with physical entrapment within the layers. We identify a significant difference in the nature of the surface-bound OC and bulk OC . We speculate that polymerization reactions may be occurring at depth within the layers. We also propose that these processes must be considered in future studies of OC in natural systems.

Minerals are known to stabilize organic carbon in sediments, affecting biogeochemical cycles and global climate, but the mechanism is not understood. Here, the authors suggest that manganese oxides can trap organic carbon and may act as a ‘mineral pump', transforming carbon between labile and refractory forms.

Hematopoietic androgen receptor deficiency promotes visceral fat deposition in male mice without impairing glucose homeostasis

Androgen deficiency in men increases body fat, but the mechanisms by which testosterone suppresses fat deposition have not been elucidated fully. Adipose tissue macrophages express the androgen receptor (AR) and regulate adipose tissue remodeling. Thus, testosterone signaling in macrophages could alter the paracrine function of these cells and thereby contribute to the metabolic effects of androgens in men. A metabolic phenotyping study was performed to determine whether the loss of AR signaling in hematopoietic cells results in greater fat accumulation in male mice. C57BL/6J male mice (ages 12-14 weeks) underwent bone marrow transplant from either wild-type (WT) or AR knockout (ARKO) donors (n = 11-13 per group). Mice were fed a high-fat diet (60% fat) for 16 weeks. At baseline, 8 and 16 weeks, glucose and insulin tolerance tests were performed, and body composition was analyzed with fat-water imaging by MRI. No differences in body weight were observed between mice transplanted with WT bone marrow [WT(WTbm)] or ARKO bone marrow [WT(ARKObm)] prior to initiation of the high-fat diet. After 8 weeks of high-fat feeding, WT(ARKObm) mice exhibited significantly more visceral and total fat mass than WT(WTbm) animals. Despite this, no differences between groups were observed in glucose tolerance, insulin sensitivity, or plasma concentrations of insulin, glucose, leptin, or cholesterol, although WT(ARKObm) mice had higher plasma levels of adiponectin. Resultant data indicate that AR signaling in hematopoietic cells influences body fat distribution in male mice, and the absence of hematopoietic AR plays a permissive role in visceral fat accumulation. These findings demonstrate a metabolic role for AR signaling in marrow-derived cells and suggest a novel mechanism by which androgen deficiency in men might promote increased adiposity. The relative contributions of AR signaling in macrophages and other marrow-derived cells require further investigation.

A retrospective analysis of RET translocation, gene copy number gain and expression in NSCLC patients treated with vandetanib in four randomized Phase III studies

Background

To determine the prevalence of RET rearrangement genes, RET copy number gains and expression in tumor samples from four Phase III non-small-cell lung cancer (NSCLC) trials of vandetanib, a selective inhibitor of VEGFR, RET and EGFR signaling, and to determine any association with outcome to vandetanib treatment.

Methods

Archival tumor samples from the ZODIAC (NCT00312377, vandetanib ± docetaxel), ZEAL (NCT00418886, vandetanib ± pemetrexed), ZEPHYR (NCT00404924, vandetanib vs placebo) and ZEST (NCT00364351, vandetanib vs erlotinib) studies were evaluated by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) in 944 and 1102 patients.

Results

The prevalence of RET rearrangements by FISH was 0.7% (95% CI 0.3–1.5%) among patients with a known result. Seven tumor samples were positive for RET rearrangements (vandetanib, n = 3; comparator, n = 4). 2.8% (n = 26) of samples had RET amplification (innumerable RET clusters, or ≥7 copies in > 10% of tumor cells), 8.1% (n = 76) had low RET gene copy number gain (4–6 copies in ≥40% of tumor cells) and 8.3% (n = 92) were RET expression positive (signal intensity ++ or +++ in >10% of tumor cells). Of RET-rearrangement-positive patients, none had an objective response in the vandetanib arm and one patient responded in the comparator arm. Radiologic evidence of tumor shrinkage was observed in two patients treated with vandetanib and one treated with comparator drug. The objective response rate was similar in the vandetanib and comparator arms for patients positive for RET copy number gains or RET protein expression.

Conclusions

We have identified prevalence for three RET biomarkers in a population predominated by non-Asians and smokers. RET rearrangement prevalence was lower than previously reported. We found no evidence of a differential benefit for efficacy by IHC and RET gene copy number gains. The low prevalence of RET rearrangements (0.7%) prevents firm conclusions regarding association of vandetanib treatment with efficacy in the RET rearrangement NSCLC subpopulation.

Trial registration

Randomized Phase III clinical trials (NCT00312377, ZODIAC; NCT00418886, ZEAL; NCT00364351, ZEST; NCT00404924, ZEPHYR).

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1146-8) contains supplementary material, which is available to authorized users.

Time from first presentation in primary care to treatment of symptomatic colorectal cancer: effect on disease stage and survival

Background:

British 5-year survival from colorectal cancer (CRC) is below the European average, but the reasons are unclear. This study explored if longer provider delays (time from presentation to treatment) were associated with more advanced stage disease at diagnosis and poorer survival.

Methods:

Data on 958 people with CRC were linked with the Scottish Cancer Registry, the Scottish Death Registry and the acute hospital discharge (SMR01) dataset. Time from first presentation in primary care to first treatment, disease stage at diagnosis and survival time from date of first presentation in primary care were determined. Logistic regression and Cox survival analyses, both with a restricted cubic spline, were used to model stage and survival, respectively, following sequential adjustment of patient and tumour factors.

Results:

On univariate analysis, those with <4 weeks from first presentation in primary care to treatment had more advanced disease at diagnosis and the poorest prognosis. Treatment delays between 4 and 34 weeks were associated with earlier stage (with the lowest odds ratio occurring at 20 weeks) and better survival (with the lowest hazard ratio occurring at 16 weeks). Provider delays beyond 34 weeks were associated with more advanced disease at diagnosis, but not increased mortality. Following adjustment for patient, tumour factors, emergency admissions and symptoms and signs, no significant relationship between provider delay and stage at diagnosis or survival from CRC was found.

Conclusions:

Although allowing for a nonlinear relationship and important confounders, moderately long provider delays did not impact adversely on cancer outcomes. Delays are undesirable because they cause anxiety; this may be fuelled by government targets and health campaigns stressing the importance of very prompt cancer diagnosis. Our findings should reassure patients. They suggest that a health service's primary emphasis should be on quality and outcomes rather than on time to treatment.

Antibody validation of immunohistochemistry for biomarker discovery: recommendations of a consortium of academic and pharmaceutical based histopathology researchers

As biomarker discovery takes centre-stage, the role of immunohistochemistry within that process is increasing. At the same time, the number of antibodies being produced for “research use” continues to rise and it is important that antibodies to be used as biomarkers are validated for specificity and sensitivity before use. This guideline seeks to provide a stepwise approach for the validation of an antibody for immunohistochemical assays, reflecting the views of a consortium of academic and pharmaceutical based histopathology researchers. We propose that antibodies are placed into a tier system, level 1–3, based on evidence of their usage in immunohistochemistry, and that the degree of validation required is proportionate to their place on that tier.

Identification of a subset of human non-small cell lung cancer patients with high PI3Kβ and low PTEN expression, more prevalent in squamous cell carcinoma

PURPOSE

The phosphoinositide 3-kinase (PI3K) pathway is a major oncogenic signaling pathway and an attractive target for therapeutic intervention. Signaling through the PI3K pathway is moderated by the tumor suppressor PTEN, which is deficient or mutated in many human cancers. Molecular characterization of the PI3K signaling network has not been well defined in lung cancer; in particular, the role of PI3Kβ and its relation to PTEN in non-small cell lung cancer NSCLC remain unclear.

EXPERIMENTAL DESIGN

Antibodies directed against PI3Kβ and PTEN were validated and used to examine, by immunohistochemistry, expression in 240 NSCLC resection tissues [tissue microarray (TMA) set 1]. Preliminary observations were extended to an independent set of tissues (TMA set 2) comprising 820 NSCLC patient samples analyzed in a separate laboratory applying the same validated antibodies and staining protocols. The staining intensities for PI3Kβ and PTEN were explored and colocalization of these markers in individual tumor cores were correlated.

RESULTS

PI3Kβ expression was elevated significantly in squamous cell carcinomas (SCC) compared with adenocarcinomas. In contrast, PTEN loss was greater in SCC than in adenocarcinoma. Detailed correlative analyses of individual patient samples revealed a significantly greater proportion of SCC in TMA set 1 with higher PI3Kβ and lower PTEN expression when compared with adenocarcinoma. These findings were reinforced following independent analyses of TMA set 2.

CONCLUSIONS

We identify for the first time a subset of NSCLC more prevalent in SCC, with elevated expression of PI3Kβ accompanied by a reduction/loss of PTEN, for whom selective PI3Kβ inhibitors may be predicted to achieve greater clinical benefit.

Validation of the BRCA1 antibody MS110 and the utility of BRCA1 as a patient selection biomarker in immunohistochemical analysis of breast and ovarian tumours

BRCA1 protein measurement has previously been evaluated as a potential diagnostic marker without reaching a conclusive recommendation. In this study, we applied current best practice in antibody validation to further characterize MS110, a widely used antibody targeting BRCA1. Antibody specificity was investigated using different biochemical validation techniques. We found that BRCA1 could not be reliably detected using immunoprecipitation and Western blot in endogenously expressing cells. We used immunohistochemistry on formalin-fixed paraffin-embedded cell pellets to establish compatibility with formalin-fixed paraffin-embedded samples. We demonstrated that in transfected cells and cell lines with known genetic BRCA1 status, MS110 successfully detected BRCA1 giving the expected level of staining in immunohistochemistry. Following this, we investigated the use of BRCA1 protein measurement by immunohistochemistry in a cohort of triple negative breast and serous ovarian tumour samples to explore the use of BRCA1 protein measurement by immunohistochemistry for patient stratification. Using MS110 in repeated standardized experiments, on serial sections from a panel of patient samples, results demonstrated considerable run-to-run variability. We concluded that in formalin-fixed tissue samples, MS110 does detect BRCA1; however, using standard methodologies, BRCA1 expression levels in tissue samples is incompatible with the use of this protein as a statistically robust patient selection marker in immunohistochemistry. These results demonstrate the need for further development to deliver BRCA1 protein quantification by immunohistochemistry as a patient stratification marker.

Abstract 4172: Identification of a low PTEN / high PI3Kα expressing subset of squamous non-small-cell lung cancer (NSCLC)

Background The PI3K/AKT/mTOR signalling network is a critical regulator of many cellular processes including proliferation, survival and transformation. PI3Kα and PI3Kα are positioned on chromosome 3q (3q25-27), a region often amplified in NSCLC. The activity of the PI3K enzymes is counteracted by the tumor suppressor PTEN, a nonredundant phosphatase. Clinically, PTEN mutations and deficiencies are prevalent in many types of human cancers and severe PTEN deficiency is also associated with advanced tumor stage and therapeutic resistance. In lung cancer, loss of PTEN protein occurs via a number of mechanisms including promoter methylation and LOH, however, neither epigenetic silencing nor deletion appear to predict with protein loss by immunohistochemistry (IHC). The molecular characterization of the PI3K/AKT/mTOR signalling network in lung cancer is not as well defined as in other tumour types, yet de-regulation of this pathway has been linked to resistance to therapy (EGFR). In particular, the role of PI3Kα in NSCLC has not been studied. Methods Eight tissue microarrays (TMAs) comprising 211 surgically resected formalin-fixed paraffin-embedded NSCLC specimens (99 squamous cell carcinomas; 112 adenocarcinomas) were examined by IHC using validated antibodies directed against PI3Kα and PTEN. In addition, an independent investigation was conducted at the MDACC using the same validated antibody methods across thirty two TMAs comprising 290 squamous and 530 adenocarcinoma samples. Results Tumour expression of PI3Kα was largely cytoplasmic, while PTEN was localized to both cytoplasmic and nuclear compartments. Results from the AZ dataset reveal significantly (p&lt;0.001) elevated expression of cytoplasmic PI3Kα expression in squamous cell carcinomas compared with adenocarcinomas. Conversely, adenocarcinoma samples displayed significantly higher levels of cytoplasmic (p&lt;0.001) and nuclear (p&lt;0.001) PTEN (88.3% and 74.8% positive, respectively) compared with squamous samples (60.6% and 45.5% positive, respectively). Interestingly, over-expression of cytoplasmic PI3Kα in squamous samples correlated significantly (66.3% of squamous samples; p&lt;0.001) with negative or low cytoplasmic and nuclear PTEN expression, with only 11.5% of adenocarcinoma samples showing this pattern of expression and 50% exhibiting a converse relationship. Analyses of data derived from the MDACC identified a similar profile of expression confirming identification of a subset of squamous NSCLC samples with over-expression of PI3Kα and low or negative PTEN. Supplementary evaluation of KRAS and EGFR mutation status and survival endpoints in this segment has also been performed and will be discussed. Conclusions These data identify a pattern of over-expression of PI3Kα in squamous NSCLC that, accompanied by loss/reduced PTEN, could represent a subset for therapeutic intervention.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4172. doi:1538-7445.AM2012-4172

Comparison of the GMFM-66 and the PEDI Functional Skills Mobility domain in a group of Chinese children with cerebral palsy

BACKGROUND

Previous research has suggested there is a high level of comparability between the Gross Motor Function Measure-66 (GMFM-66) and the Pediatric Evaluation of Disability Inventory (PEDI) Functional Skills Mobility domain. However, there are only a few studies that have examined the correlations between these instruments. The purpose of this study was to determine the correlation between the GMFM-66 and the PEDI Functional Skills Mobility domain scaled scores in a group of Chinese children with spastic cerebral palsy, at the ages of 12-70 months, in order to explore the feasibility of using them interchangeably.

METHODS

Secondary data analysis was conducted of data collected during a prospective international collaborative study that used the GMFM-66 and the PEDI to examine the impact of treatment. This study examined the Pearson correlations between the GMFM-66 and the PEDI Functional Skills Mobility domain at six time points over the course of 28 consecutive weeks for 115 Chinese children who participated at baseline.

RESULTS

Pearson correlations between the GMFM-66 and the PEDI Functional Skills Mobility domain ranged from 0.83 to 0.90 for the six time points of data collection, with statistically significant P-values <0.0001 for each correlation.

CONCLUSIONS

These results support previous research that the GMFM-66 and the PEDI Functional Skills Mobility domain are complementary assessments that may be used interchangeably when it is not possible to administer both.

Which women default from follow-up cervical cytology tests? A cohort study within the TOMBOLA trial

OBJECTIVE

To identify factors associated with default from follow-up cervical cytology tests.

METHODS

A cohort study was conducted involving 2166 women, aged 20-59, with recent low-grade cervical cytology taken within the NHS Cervical Screening Programmes in Scotland and England, and managed by 6-monthly cytology in primary care. For the first (6-month) and second (12-month) surveillance cytology tests separately, women were categorized as 'on-time attendees' (attended ≤6 months of test being due), 'late attendees' (attended greater than 6 months after test was due) or 'non-attendees' (failed to attend). Multivariate odds ratios (ORs) were computed for factors associated with late and non-attendance.

RESULTS

For the first surveillance test, risk of non-attendance was significantly higher in younger women, those without post-secondary education, and non-users of prescribed contraception. Factors significantly associated with late attendance for the first test were the same as for non-attendance, plus current smoking and having children. The most important predictor of non-attendance for the second surveillance test was late attendance for the first test (OR = 9.65; 95% CI, 6.60-16.62). Non-attendance for the second test was also significantly higher among women who were younger, smokers and had negative cytology on the first surveillance test. Late attendance for the second surveillance test was higher in women who were younger, smokers, had children and attended late for the first test.

CONCLUSIONS

Women at highest risk of default from follow-up cytology tend to be young, smoke, lack post-secondary education, and have defaulted from a previous surveillance appointment. Tackling default will require development of targeted strategies to encourage attendance and research to better understand the reasons underpinning default.

Long-term psychosocial impact of alternative management policies in women with low-grade abnormal cervical cytology referred for colposcopy: a randomised controlled trial

BACKGROUND

The debate continues regarding the best management for women with low-grade abnormal cervical cytology attending colposcopy. We compared psychosocial outcomes of alternative management policies in these women.

METHODS

In all, 989 women, aged 20-59 years, with low-grade abnormal cytology, were randomised to immediate large loop excision (LLETZ) or two to four targeted punch biopsies taken immediately with recall for LLETZ if these showed cervical intra-epithelial neoplasia 2/3. At 6 weeks after the last procedure, women completed the hospital anxiety and depression scale (HADS) and the impact of event scale (IES). At 12, 18, 24 and 30 months post recruitment, women completed the HADS and process outcome specific measure (POSM). Prevalence of significant depression (≥ 8), significant anxiety (≥ 11) and distress (≥ 9) and median POSM scores were compared between arms. Multivariate odds ratios (ORs) for immediate LLETZ vs biopsy and recall were computed.

RESULTS

Over the entire follow-up, there was no significant difference between arms in cumulative prevalence or risk of significant depression (OR=0.78, 95% CI 0.52-1.17) or significant anxiety (OR=0.83, 95% CI 0.57-1.19). At 6 weeks post procedure, distress did not differ significantly between arms. At later time points, 8-11% had significant depression and 14-16% had significant anxiety but with no differences between arms. The POSM scores did not differ between the arms.

CONCLUSIONS

There is no difference in long- or short-term psychosocial outcomes of immediate LLETZ and punch biopsies with selective recall.

Vascular endothelial growth factor receptors VEGFR-2 and VEGFR-3 are localized primarily to the vasculature in human primary solid cancers

PURPOSE

Vascular endothelial growth factor (VEGF) signaling is key to tumor angiogenesis and is an important target in the development of anticancer drugs. However, VEGF receptor (VEGFR) expression in human cancers, particularly the relative expression of VEGFR-2 and VEGFR-3 in tumor vasculature versus tumor cells, is poorly defined.

EXPERIMENTAL DESIGN

VEGFR-2- and VEGFR-3-specific antibodies were identified and used in the immunohistochemical analysis of human primary cancers and normal tissue. The relative vascular localization of both receptors in colorectal and breast cancers was determined by coimmunofluorescence with vascular markers.

RESULTS

VEGFR-2 and VEGFR-3 were expressed on vascular endothelium but not on malignant cells in 13 common human solid tumor types (n > 400, bladder, breast, colorectal, head and neck, liver, lung, skin, ovarian, pancreatic, prostate, renal, stomach, and thyroid). The signal intensity of both receptors was significantly greater in vessels associated with malignant colorectal, lung, and breast than adjacent nontumor tissue. In colorectal cancers, VEGFR-2 was expressed on both intratumoral blood and lymphatic vessels, whereas VEGFR-3 was found predominantly on lymphatic vessels. In breast cancers, both receptors were localized to and upregulated on blood vessels.

CONCLUSIONS

VEGFR-2 and VEGFR-3 are primarily localized to, and significantly upregulated on, tumor vasculature (blood and/or lymphatic) supporting the majority of solid cancers. The primary clinical mechanism of action of VEGF signaling inhibitors is likely to be through the targeting of tumor vessels rather than tumor cells. The upregulation of VEGFR-3 on tumor blood vessels indicates a potential additional antiangiogenic effect for dual VEGFR-2/VEGFR-3-targeted therapy.

Vascular endothelial growth factor receptors VEGFR-2 and VEGFR-3 are localized primarily to the vasculature in human primary solid cancers

PURPOSE

Vascular endothelial growth factor (VEGF) signaling is key to tumor angiogenesis and is an important target in the development of anticancer drugs. However, VEGF receptor (VEGFR) expression in human cancers, particularly the relative expression of VEGFR-2 and VEGFR-3 in tumor vasculature versus tumor cells, is poorly defined.

EXPERIMENTAL DESIGN

VEGFR-2- and VEGFR-3-specific antibodies were identified and used in the immunohistochemical analysis of human primary cancers and normal tissue. The relative vascular localization of both receptors in colorectal and breast cancers was determined by coimmunofluorescence with vascular markers.

RESULTS

VEGFR-2 and VEGFR-3 were expressed on vascular endothelium but not on malignant cells in 13 common human solid tumor types (n > 400, bladder, breast, colorectal, head and neck, liver, lung, skin, ovarian, pancreatic, prostate, renal, stomach, and thyroid). The signal intensity of both receptors was significantly greater in vessels associated with malignant colorectal, lung, and breast than adjacent nontumor tissue. In colorectal cancers, VEGFR-2 was expressed on both intratumoral blood and lymphatic vessels, whereas VEGFR-3 was found predominantly on lymphatic vessels. In breast cancers, both receptors were localized to and upregulated on blood vessels.

CONCLUSIONS

VEGFR-2 and VEGFR-3 are primarily localized to, and significantly upregulated on, tumor vasculature (blood and/or lymphatic) supporting the majority of solid cancers. The primary clinical mechanism of action of VEGF signaling inhibitors is likely to be through the targeting of tumor vessels rather than tumor cells. The upregulation of VEGFR-3 on tumor blood vessels indicates a potential additional antiangiogenic effect for dual VEGFR-2/VEGFR-3-targeted therapy.

Characterization of AZD8931, a potent reversible small molecule inhibitor against epidermal growth factor receptor (EGFR), erythroblastic leukemia viral oncogene homolog 2 (HER2) and 3 (HER3) with a unique and balanced pharmacological profile

11072

Background: Successful combined pharmacological inhibition of EGFR, HER2, and HER3 signaling is currently under investigation in the clinic. HERs (erbB receptors including EGFR, erbB2, erbB3, erbB4) undergo various types of alteration and in many cancers HER ligands are produced either by the tumor cells themselves or surrounding stromal cells. These mechanisms of receptor activation all lead to constitutive proliferative and/or survival signaling driven by homo- and/or heterodimerization of the HER family. Characterization of a novel tyrosine kinase inhibitor with a potent and balanced profile against EGFR, HER2 (erbB2), and HER3 (erbB3) has been carried out. Methods: A range of assays has been developed to assess the detailed pharmacology of AZD8931 and understand how the profile of AZD8931 compares with other HER family inhibitors, such as gefitinib and lapatinib. These assays have provided unique insights into the pharmacology of these drugs that result from the varying levels of HER and their associated ligands. Results: Across a number of cell systems, AZD8931 has been shown to be a potent inhibitor of tumor cell growth. This effect is through the ability of AZD8931 to inhibit potently the phosphorylation of EGFR (0.004 μM; 95% CIR: 1.377), HER2 (0.003 μM; 95% CIR: 1.817) and HER3 (0.004 μM; 95% CIR: 1.890) in a balanced manner. Furthermore, when compared to control AZD8931 has significant and dramatic effects on the downstream signaling pathways (pAKT [p=0.002] & pMAK [NS]), apoptotic (M30 [p=0.004]), and proliferative (Ki67 [p<0.0005]) endpoints. The novel agent AZD8931 displays a distinct pharmacological profile compared to both gefitinib and lapatinib. Conclusions: Based on our data as well as published literature, the combined pharmacological inhibition of EGFR, HER2, and HER3 signaling has not yet been tested in the clinic. AZD8931 offers an agent to test the hypothesis that combined inhibition of HER signaling could provide additional clinical benefit in cancer, particularly in the majority of solid tumors that do not overexpress HER2.

[Table: see text]

COPD-related morbidity and mortality after smoking cessation: status of the evidence

The evidence base for the benefit of quitting smoking as regards morbidity and mortality outcomes in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD) is limited. The present article is a review of the existing literature. A systematic literature search in medical databases was performed until March 2006, and subsequently until September 1, 2007. The outcomes examined were COPD-related morbidity and mortality (including all-cause mortality) in COPD patients in connection with smoking cessation. A total of 21 and 27 published articles on morbidity and mortality, respectively, were identified and reviewed. For both outcomes, only a few of the studies included patients with severe COPD. Most of the studies reported a beneficial effect of smoking cessation compared with continued smoking, whereas a few found no improvement. Methodological problems, including small study sizes, poor data quality, possibility of reverse causality and incomplete ascertainment of cause of death, limit interpretation of some of the studies. The evidence as a whole supports the conclusion that, even in severe chronic obstructive pulmonary disease, smoking cessation slows the accelerated rate of lung function decline and improves survival compared with continued smoking.

Short stature: increased in children with severe learning disability

INTRODUCTION

'Health for all children' recommends that children should be screened for growth disorders at school entry with a 0.4th centile 'cut-off'. Following the diagnosis of growth hormone deficiency in four children attending local special schools, our aim was to compare the height distribution of children attending special schools with mainstream schools.

METHODS

Children at two local special schools were measured using a Leicester height measurer and values converted to standard deviation scores (SDS). Children were categorized according to whether there were known factors that could affect height. The data were compared with those collected from local mainstream schools.

RESULTS

In total, 242 children were registered at the two special schools and 192 children were measured. The mean height SDS of children in mainstream school (n = 2301) was similar to national standards at -0.09 (SD 1.02). The mean height SDS distribution of the 192 children in special schools (age range 3.2-18.4 years; median age 11.3 years) was -0.73; 95%CI -0.9 to -0.5. In those with no established diagnosis to explain altered growth (n = 120) this was -0.613; 95%CI -0.8 to -0.4. Both pre-pubertal (n = 37) and pubertal (n = 83) children were short and eight (6.7%) had a height less than the 0.4th centile.

CONCLUSIONS

Children attending special school with severe or profound learning disability were shorter than those attending mainstream school. This is still the case following the exclusion of children with a known cause for abnormal growth. This underlines the importance of each child being assessed by professionals with a refined knowledge of normal and abnormal growth.

Semantic security: specification and enforcement of semantic policies for security-driven collaborations

Collaborative research can often have demands on finer-grained security that go beyond the authentication-only paradigm as typified by many e-Infrastructure/Grid based solutions. Supporting finer-grained access control is often essential for domains where the specification and subsequent enforcement of authorization policies is needed. The clinical domain is one area in particular where this is so. However it is the case that existing security authorization solutions are fragile, inflexible and difficult to establish and maintain. As a result they often do not meet the needs of real world collaborations where robustness and flexibility of policy specification and enforcement, and ease of maintenance are essential. In this paper we present results of the JISC funded Advanced Grid Authorisation through Semantic Technologies (AGAST) project (www.nesc.ac.uk/hub/projects/agast) and show how semantic-based approaches to security policy specification and enforcement can address many of the limitations with existing security solutions. These are demonstrated into the clinical trials domain through the MRC funded Virtual Organisations for Trials and Epidemiological Studies (VOTES) project (www.nesc.ac.uk/hub/projects/votes) and the epidemiological domain through the JISC funded SeeGEO project (www.nesc.ac.uk/hub/projects/seegeo).