Non-Hodgkin Lymphoma Causing Hypopituitarism Can Imaging Help Diagnosis and Management?

Non-Hodgkin lymphomas of the hypothalamus and pituitary are rare. They usually remain clinically silent until onset of compressive features affecting surrounding structures. When symptomatic, patients most commonly present with diabetes insipidus, headaches, ophthalmoplegia and/or bilateral hemianopia.  We report a case of a 67-year-old Caucasian female with a history of B-cell lymphoma in complete remission. She presented with left oculomotor nerve palsy and was subsequently found to have a sellar/suprasellar mass lesion on MRI. Alongside hypocortisolism and hypogonadotropic hypogonadism, she developed transient diabetes insipidus during her illness. Her clinical course was characterized by rapid intracranial progression of the sellar mass. MR spectroscopy suggested a diagnosis of lymphoma. Diagnostic biopsy confirmed high-grade diffuse large B-cell CNS lymphoma; this changed the definitive management from surgical excision to chemotherapy. Despite treatment, she succumbed to her illness within 7 months of initial presentation. This case highlights the aggressive nature of CNS lymphomas and the need for a high index of suspicion in an unusual presentation of sellar/suprasellar mass lesions.

AB0077 ASSOCIATION BETWEEN VITAMIN D RECEPTOR GENE POLYMORPHISMS AND SYSTEMIC LUPUS ERYTHEMATOSUS IN MALTESE PATIENTS

Background:

Vitamin D deficiency is highly prevalent in patients with systemic lupus erythematosus (SLE). Vitamin D acts through the vitamin D receptor (VDR) that is present in most cells, and it can regulate the transcription of over 200 genes. The expression of vitamin D receptors by a variety of cells belonging to the innate and adaptive immune systems has created interest with regards to the role of vitamin D in the pathogenesis of SLE. Several polymorphisms of the VDR gene have been described, namely Bsml, Apal, Taql and Fokl. A number of VDR gene polymorphism genotypes have been associated with increased risk of SLE mostly in Asians and Africans.1

Objectives:

The aim of this study was to establish whether an association was present between VDR gene polymorphisms and SLE susceptibility in a cohort of SLE patients living in Malta. A further aim was to assess the relationship between these VDR gene polymorphisms and SLE disease characteristics.

Methods:

59 SLE patients living in Malta and attending Rheumatology clinic at Mater Dei Hospital were recruited for the study after providing informed consent. The patients were over the age of 18 years and fulfilled the SLICC classification criteria for SLE. The patients were interviewed and blood samples were taken. RNA extraction was performed from whole blood. QuantiGene Plex technology was used to measure the expression of 12 interferon (IFN) signature genes in the extracted RNA.

93 cord blood samples obtained from individuals living in Malta were used as a control. DNA extraction was carried out from the blood samples obtained from the patients and controls. The VDR gene was screened and the regions containing the VDR polymorphisms were amplified for each patient. The amplified regions were then digested with their respective restriction enzymes in order to view the patient’s genotype via restriction fragment length polymorphism. Statistical analysis, including odds ratio (OR), was carried out to gauge the significance in the association of these polymorphisms with SLE.

Results:

94.9% of SLE patients were female and they had a mean age of 44.5 years. All the patients were of Caucasian ethnicity. 13.6% had vitamin D deficiency (serum 25-hydroxyvitamin D <20ng/ml) and 25.4% were vitamin D insufficient (serum 25-hydroxyvitamin D 20-29ng/ml). The results showed that when ApaI polymorphism was present as a homozygote for the variant allele there was a significant decrease in SLE prevalence (OR=0.39, CI 0.17-0.87, p=0.02). The results were also analysed by placing the polymorphs into haplotypes. The haplotype containing all wild-type alleles for the VDR gene and the haplotype containing all wild-type alleles with the variant allele for FokI had an increased prevalence of SLE (OR= 1.95, CI 1.12-3.38, p=0.01 and OR= 2.36, CI 1.13-4.91, p=0.02 respectively).

The patients who were homozygous for the variant allele for BsmI had a significantly higher SLE disease activity index-2K (SLEDAI-2K) (mean 5.00) compared to those that were heterozygous (mean 2.66; p=0.010). No significant difference was noted in damage, IFN signature gene expression, organ manifestation and autoantibody profile between the different genotypes for the 4 VDR polymorphisms. SLE patients who were homozygous variant for the ApaI or TaqI polymorphisms had an increased prevalence of fibromyalgia (OR=7.50, CI 1.47-38.16, p=0.02 and OR=12.00, CI 1.80-80.05, p=0.02 respectively).

Conclusion:

The study showed that in the Maltese population the presence of the VDR gene polymorphism haplotype containing all wild-type alleles and the haplotype containing all wild-type alleles with the variant allele for FokI are associated with an increased risk of SLE. Moreover the homozygous variant genotype for BsmI was associated with a higher SLE disease activity. The homozygous variant genotype for ApaI and TaqI was associated with a higher risk of fibromyalgia in SLE patients.

References:

[1]Zhou TB, Jiang ZP, Lin ZJ, Su N. Association of vitamin D receptor gene polymorphism with the risk of systemic lupus erythematosus. J Recept Signal Transduct Res. 2015;35(1):8-14.

Acknowledgements:

The Faculty of Medicine and Surgery, University of Malta provided funding for this research.

Disclosure of Interests:

None declared

POS0101 ADVERSE HEALTH-RELATED QUALITY OF LIFE OUTCOME DESPITE ADEQUATE CLINICAL RESPONSE TO TREATMENT IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Despite improvements in medical care that have contributed to prolonged life expectancy for people living with systemic lupus erythematosus (SLE) over the past decades, they still suffer from substantial diminutions of health-related quality of life (HRQoL) compared with the general population and with other chronic diseases.

Some studies have demonstrated that conventional synthetic and biological disease-modifying agents contribute to improvements in SLE patients’ HRQoL, and responders to treatment have been shown to report greater improvements than non-responders. Although these observations are clinically relevant, improvement following a therapeutic intervention does not necessarily signify that the individual has achieved a satisfactory health state perception. In rheumatoid arthritis, significant pain and severe fatigue persist in a substantial proportion of patients who achieve a good clinical response to treatment or remission. This paradoxical observation has not been thoroughly explored in SLE.

Objectives:

To determine the prevalence of adverse HRQoL outcomes in patients with SLE who achieved an adequate clinical response after a 52-week long period on standard therapy plus belimumab or placebo, within the frame of two phase III clinical trials. We further aimed to compare frequencies of adverse HRQoL outcomes across different age categories and ethnic groups, and sought to identify contributing factors.

Methods:

We included patients who met the primary endpoint of the BLISS-52 (NCT00424476) and BLISS-76 (NCT00410384) trials (N=760/1684), i.e. attainment of the SLE Responder Index 4 at week 52. Accordingly, evaluation of adverse HRQoL outcomes was based on patient reports at week 52 from treatment initiation, using the Medical Outcomes Study Short Form 36 (SF-36) health survey and the Functional Assessment of Chronic Illness Therapy Fatigue (FACIT-Fatigue) scale. Adverse HRQoL outcomes were defined as (i) SF-36 scale scores ≤ the 5th percentile derived from age- and sex-matched US population-based norms from the SF-36 health survey user manual; and (ii) FACIT-Fatigue scores <30.

Pearson’s chi-square or Fisher’s exact tests were used to investigate associations between dichotomous variables. Comparisons of continuous data between SLE patients and age- and sex-matched norms were performed using the Wilcoxon signed-rank test. Multivariable logistic regression models were created in order to assess independence and priority of potential factors associated with adverse HRQoL outcomes.

Results:

We found clinically important diminutions of HRQoL in SLE patients compared with matched norms and high frequencies of adverse HRQoL outcomes, the highest in SF-36 general health (29.1%), followed by FACIT-Fatigue (25.8%) and SF-36 physical functioning (25.4%). Overall, frequencies were higher with increasing age. Black/African American and White/Caucasian patients reported higher frequencies than Asians and Indigenous Americans, while Hispanics experienced adverse HRQoL less frequently than non-Hispanics. Increasing organ damage was associated with adverse physical but not mental HRQoL outcomes; disease activity showed no impact. In multivariable logistic regression analysis, addition of belimumab to standard therapy was associated with lower frequencies of adverse SF-36 physical functioning (OR: 0.59; 95% CI: 0.39–0.91; P=0.016) and FACIT-F (OR: 0.53; 95% CI: 0.34–0.81; P=0.004).

Conclusion:

Substantial proportions of SLE patients reported adverse HRQoL outcomes despite adequate clinical response to treatment, especially in physical aspects. Particularly high proportions were seen within Black/African American and White/Caucasian patients. Add-on belimumab may be protective against adverse physical functioning and severe fatigue. Our results corroborate that HRQoL diminutions constitute a substantial burden in patients with SLE, and highlight the limitations of current therapeutic strategies.

Acknowledgements:

The authors would like to thank GlaxoSmithKline (Uxbridge, UK) for sharing the data from the BLISS-52 (NCT00424476) and BLISS-76 (NCT00410384) trials with the Clinical Study Data Request (CSDR) consortium, Dimitris Ladakis, Joaquin Matilla and Martin Pehr for contributing to the management of data, as well as all participating patients.

Disclosure of Interests:

Alvaro Gomez: None declared, Julius Lindblom: None declared, Victor Qiu: None declared, Arvid Cederlund: None declared, Alexander Borg: None declared, Sharzad Emamikia: None declared, Yvonne Enman: None declared, Jon Lampa: None declared, Ioannis Parodis Grant/research support from: Research funding and/or honoraria from Amgen, Elli Lilly and Company, Gilead Sciences, GlaxoSmithKline and Novartis.

THU0235 VITAMIN D AND INTERFERON SIGNATURE GENE EXPRESSION IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Vitamin D deficiency is more prevalent in patients with systemic lupus eythematosus (SLE) as a result of sun avoidance.1The potential negative impact of vitamin D deficiency on SLE disease activity has been shown in a number of studies.2The expression of the interferon signature genes in SLE correlates positively with disease activity, and these genes are thought to mediate the clinical manifestations of the disease.3

Objectives:

The aim of this study was to establish whether a relationship exists between serum 25-hydroxyvitamin D level and the interferon signature gene expression in whole blood of SLE patients.

Methods:

Informed consent was obtained from 92 SLE patients who were over the age of 18 and who fulfilled the SLICC classification criteria for SLE. The patients were interviewed and blood samples were taken. SLE disease activity was measured by SLE disease activity index-2K (SLEDAI-2K). RNA extraction was performed from whole blood. QuantiGene Plex technology was used to measure the expression of 12 interferon signature genes in the extracted RNA. The study was approved by the University Research Ethics Committee.

Results:

92.4% of the cohort studied were female. 58.7% were receiving vitamin D3 supplementation at a mean dose of 1031IU daily. 27.2% had vitamin D insufficiency (25-hydroxyvitamin D 21-29ng/ml) and 15.2% were vitamin D deficient (25-hydroxyvitamin D <20ng/ml). Mean serum 25-hydroxyvitamin D was 30.75ng/ml (standard deviation 9.53 ng/ml). Median SLEDAI-2K was 4 (range 0-12). Serum 25-hydroxyvitamin D had a significant negative correlation with body mass index (BMI) (R=-0.258, p=0.006) but there was no significant negative correlation with SLEDAI-2K or with the expression of the interferon signature genes. The expression of most interferon signatures genes measured (IFI35, OAS1, MX1, IFITM1, STAT2, IFIT3, IFIT1, STAT1, SOCS1) had a significant positive correlation with SLEDAI-2K.

Conclusion:

This study did not show a significant relationship between serum vitamin D level and disease activity. In keeping with this, there was no significant negative correlation between serum 25-hydroxyvitamin D and interferon signature gene expression. Further prospective studies and randomised controlled trials are required to study this relationship in greater depth.

References:

[1]Kamen DL, Cooper GS, Bouali H, Shaftman SR, Hollis BW, Gilkeson GS. Vitamin D deficiency in systemic lupus erythematosus. Autoimmun Rev. 2006; 5: 114-7.

[2]Sahebari M, Nabavi N, Salehi M. Correlation between serum 25(OH)D values and lupus disease activity: an original article and a systematic review with meta-analysis focusing on serum VitD confounders.Lupus2014; 23: 1164-77.

[3]Arasappan D, Tong W, Mummaneni P, Fang H, Amur S. Meta-analysis of microarray data using a pathway-based approach identifies a 37-gene expression signature for systemic lupus erythematosus in human peripheral blood mononuclear cells. BMC Med. 2011; 9: 65.

Disclosure of Interests: :

None declared

FRI0178 PREDICTIVE FACTORS FOR POOR SLEEP QUALITY IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Poor sleep quality is common in systemic lupus erythematosus (SLE) and could contribute to fatigue, which is regarded as one of the most disabling symptoms in SLE. The Pittsburgh sleep quality index (PSQI) is a validated self-administered questionnaire that measures sleep quality over the previous month.1

Objectives:

The aim of this study was to analyse the relationship of sleep quality with several variables including depression, anxiety, pain, disease activity, fatigue and functional disability in patients with SLE. A further aim was to establish the prevalence of poor sleep quality in SLE.

Methods:

A cohort cross-sectional study was carried out including 92 SLE patients who fulfilled the SLICC classification criteria for SLE and who provided informed consent for participation. The patients were interviewed and they were asked to fill in questionnaires including PSQI, Fatigue Severity Scale (FSS), Hospital Anxiety and Depression Scale (HADS), visual analogue scale (VAS) for pain and modified Health Assessment Questionnaire (mHAQ). Blood and urine tests enabled the calculation of SLE disease activity index-2K (SLEDAI-2K). The study was approved by the University Research Ethics Committee.

Results:

92.4% of the cohort studied were females, and the mean age was 46.9 years (range 19-79 years). 55.4% were noted to have poor quality sleep (PSQI >5), and the median PSQI was 6 (range 0-18). Sleep quality measured by PSQI, had a significant correlation with SLEDAI-2K (R=0.254, p=0.014), VAS pain (R=0.515, p<0.001), HADS-D (R=0.605, p<0.001), HADS-A (R=0.375, p<0.001), estimated glomerular filtration rate (eGFR) (R=-0.211, p=0.044), FSS (R=0.551, p<0.001) and mHAQ (R=0.559, p<0.001). ANCOVA analysis showed that PSQI was significantly dependant on VAS pain (p<0.001), HADS-D (p<0.001) and eGFR (p=0.003).

Conclusion:

Poor sleep quality is highly prevalent in SLE patients. This study has shown that the strongest predictive factors for poor sleep quality are pain, depression and impaired renal function. Since poor sleep quality is significantly related to fatigue and functional disability, its identification and management is important for patients’ wellbeing.

References:

[1]Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res. 1989; 28: 193 – 213.

Disclosure of Interests:

None declared

P1835 Recognising extracardiac findings in cardiac imaging - a comparison between cardiologists and radiologists

Background

In the past, cardiac imaging modalities did not obtain much information about extracardiac structures. With the introduction of newer modalities such as CT and MRI, diagnostic quality images of structures surrounding the heart are now being obtained. This has led to the need for interpretation of images of extracardiac structures. Nowadays, this is being performed by cardiologists and radiologists; either separately or conjointly.

Purpose

To evaluate whether there is any difference in the rate of positive extracardiac findings (ECF) between radiologists and cardiologists and to assess whether these ECF are of any clinical importance.

Methods

All patients having had a cardiac MRI and cardiac CT performed in the year 2017 in a single centre were enrolled (n = 733). Reports of these images were reviewed retrospectively and information was obtained as regards to any differences in number of ECF picked up by cardiologists, radiologists or both working together. These ECF were then stratified according to their clinical importance and these subdivisions compared in the context of reporting physician.

Results

A total of 733 scans were reviewed, 219 (29.9%) of these had positive ECF whilst 514 (70.1%) had none. Of the total amount, 314 (42.8%) were reported by cardiologists, 318 (43.4%) by radiologists and 101 (13.8%) jointly by both a cardiologist and a radiologist. Cardiologists found positive ECF in 18.2% of scans reviewed, radiologists reported findings in 37.4% of scans and, of those reported jointly, 42.6% were positive, p= &lt;0.001. A pattern emerged where cardiologists found less clinically significant ECF with only 5.3% of findings classified as will definitely change management, in comparison to 19.3% by radiologists and 16.3% when reviewed jointly; and, only 15.8% of findings classified as will probably change management when compared to 23.5% by radiologists and 23.3% when reviewed jointly. However, it is important to note that this pattern was not statistically significant, p = 0.1432.

Conclusions

A strongly statistically significant difference in the reporting of extracardiac findings has been highlighted in this article with cardiologists picking up less than half of extracardiac findings reported by radiologists. There was a pattern of cardiologists recognising less clinically important extracardiac findings, however this was not found to be statistically significant. These results should be reviewed with caution, taking into consideration the limitations of results obtained from a single centre. However, should this pattern keep repeating itself, one might consider increasing cardiologist training in ECF or having cardiac imaging reported conjointly by a cardiologist and a radiologist. Further studies are also necessary to ascertain the clinical relevance of the difference in ECF between cardiologists, radiologists or both specialists working together.

P1691 A case of congenital pulmonary stenosis

Introduction

We present an unusual case of sequential right ventricular outflow tract obstruction (RVOTO) caused by pulmonary and subpulmonary stenosis, with formation of aortopulmonary collaterals.

Case presentation

We report a case of a 47 year old Senegalese man who presented with a three year history of shortness of breath on exertion which worsened over the past week. Cardiovascular examination revealed a parasternal heave, a systolic murmur loudest in the pulmonary area and no evidence of fluid overload.

A transthoracic echocardiogram revealed leftward septal deviation during systole due to right ventricular pressure overload, severe right ventricular hypertrophy (RV free wall end-diastolic thickness of 8mm) and normal systolic function (FAC 47%), a dilated right atrium and moderate tricuspid regurgitation with estimated maximum pressures of 112mmHg. On continuous-wave doppler of the right ventricular outflow tract (RVOT), there was a late peaking systolic flow with maximum velocity of 3.8m/s.

A cardiac computed tomography (CT) and cardiac magnetic resonance imaging (MRI) was performed which showed sequential stenoses of the RVOT; one at subvalvular level by an infundibular muscular ridge with an area of 0.7 cm2 in mid-systole and one at the level of a dome-shaped pulmonary valve with planimetered valve area of 0.5cm2, severe RV hypertrophy and normal RV ejection fraction. Aortopulmonary collaterals from proximal thoracic descending aorta were seen. The main pulmonary artery was shown to be dilated with no evidence of pulmonary artery branch stenosis. See image: In-plane phase contrast velocity flow mapping of the RVOT using a VENC of 80cm/s, showing aliasing at the level of the pulmonary valve (red arrow) and at the level of the infundibulum (white arrow).

Conclusion

Congenital pulmonary stenosis (PS) occurs in 8% of congenital heart defects. 80% of pulmonary valve stenosis is typically dome-shaped with commissural fusion whilst the remainder is of the dysplastic type. Congenital PS can be associated with RVOTO at the infundibular level secondary to reactive muscular hypertrophy. In our case, there is a discrete, circumferential muscular ridge at the level of the infundibulum resulting in sequential outflow tract obstruction.

PS with intact ventricular septum occurs in conjunction with varying degrees of right ventricular hypertrophy and elevated right ventricular systolic pressures. A dilated pulmonary artery is common in dome-shaped subtype of PS.

Survival into adulthood of severe PS is primarily dependent on the adequacy of pulmonary blood flow from systemic-to-pulmonary collateral arteries, which serve as an additive, or the only source of blood supply to the pulmonary arterial vasculature. These collaterals are usually seen in association with cyanotic congenital heart disease such as pulmonary atresia and tetralogy of fallot.

Abstract P1691 Figure. Sequential RVOTO

P1839 Extracardiac findings in cardiac CT and MRI - a Maltese perspective

Background

Cardiac CT and MRI are relatively new, non-invasive modalities of cardiac imaging, obtaining excellent image quality mainly pertaining to the heart. However, both these modalities also obtain diagnostic quality images of extracardiac structures. International studies quote varying rates of positive extracardiac findings (ECF) ranging from 20-30% in cardiac MRI and 30-40% in CT.

Purpose

To evaluate the prevalence of incidental ECF in cardiac imaging in the Maltese Islands and assess for any differences in prevalence between sexes and age groups.

Methods

All patients having performed cardiac CT and cardiac MRI scans performed in the year 2017 in the Maltese Islands (n = 733) were enrolled. Imaging reports of these scans were retrospectively reviewed, making a note of the patient’s age and sex and any positive ECF. ECF were then subdivided according to clinical significance and anatomical site.

Results

Positive ECF were present in 219 (29.9%), whilst 514 (70.1%) had no ECF of note. When subdivided, 14.6% of MRI and 35.0% of CT were positive for ECF, p &lt; 0.001. There was a propensity for older patients to have more positive findings, with these present in 11.9% of patients aged &lt;20, 8.1% of patients aged 20-29, 18.2% of patients aged 30-39, 21.9% of patients aged 40-49, 30.1% of patients aged 50-59 and 40.5% of patients aged ≥60, p= &lt;0.001. Females had a higher proportion of positive findings (38.1%) despite having less total scans (n = 312) when compared to men (23.8%, n = 421), p= &lt;0.001. Of the positive findings, 72.1% were newly discovered. These were classified according to clinical significance with 17.7% of these findings classified as definitely resulting in a change in management, 19.0% most likely resulting in a change in management, 46.8% possibly resulting in a change in management and 16.5% being normal variants or expected post-operative changes. Findings were most commonly lung pathologies (28.8%) followed by gastrointestinal pathologies (21.5%) and liver and gall bladder pathologies (14.6%).

Conclusions

ECF in cardiac imaging are common in the Maltese islands with around a third of all scans having a positive finding. CT was the imaging modality that was more likely to pick up ECF. ECF are increasingly frequent in older patients and also more likely to be found in females, despite less women having been scanned than males. Most findings were newly discovered with a large proportion being of clinical relevance.

WM1-5 Predictors of retreatment of anterior communicating artery aneurysms after endovascular embolisation

Objectives

To establish recurrence and retreatment rates of anterior communicating artery aneurysms (ACom) after endovascular embolization and the complication rate of retreatment. To establish predicting morphological characteristics that would favour surgery or endovascular coiling.

Design

Retrospective review of all ACom aneurysms treated at a single neurological centre over a thirteen-year period.

Subjects

Patients undergoing endovascular treatment of ACom aneurysms.

Methods

Aneurysm and patient characteristics were recorded for retreated patients. Analysis of retreatment predictors on imaging was made.

Results

Between 2005 and 2018, 510 Acom aneurysms were treated, of which 456 presented with SAH and 54 were elective. Out of these, 36 underwent re-treatment. Out of the re-treated aneurysms 33 were identified from radiological follow up and three presented with a re-bleed. The complication rate from the second endovascular procedure was 5.6%. Four patients underwent surgical clipping after failed coiling. Retreatment was more likely in ruptured aneurysms. The dome shape, size (mm) and orientation, were recorded for both aneurysms requiring retreatment and aneurysms successfully excluded after the first procedure. Other parameters reported included time interval, coiling technique (balloon-assisted/stent-assisted).

Conclusions

Recurrence of Acom aneurysms after coiling carries significant morbidity. Recognising predictors of recurrence would help identify those aneurysms that are better treated with surgery.

Decreased placental glypican expression is associated with human fetal growth restriction

Placental mediated fetal growth restriction (FGR) is a leading cause of perinatal morbidity and mortality. Heparan sulphate proteoglycans (HSPG) are highly expressed in placentae and regulate haemostasis. We hypothesise that altered expression of HSPGs, glypicans (GPC) may contribute to the development of FGR and small-for-gestational-age (SGA). GPC expression was determined in first-trimester chorionic villous samples collected from women with later SGA pregnancies and in placentae from third-trimester FGR and gestation-matched uncomplicated pregnancies. The expression of both GPC1 and GPC3 were significantly reduced in first-trimester SGA as well as in the third-trimester FGR placentae compared to controls. This is the first study to report a relationship between altered placental GPC expression and subsequent development of SGA/FGR.

Defect-Induced Water Bilayer Growth on Anatase TiO2(101)

Preparing an anatase TiO₂(101) surface with a high density of oxygen vacancies and associated reduced Ti species in the near-surface region results in drastic changes in the water adsorption chemistry compared to adsorption on a highly stoichiometric surface. Using synchrotron radiation excited photoelectron spectroscopy, we observe a change in the water growth mode, from layer-by-layer growth on the highly stoichiometric surface to bilayer growth on the reduced surface. Furthermore, we have been able to observe Ti³⁺ enrichment at the surface upon water adsorption. The Ti³⁺ enrichment occurs concomitant with effective water dissociation into hydroxyls with a very high thermal stability. The water bilayer on the reduced surface is thermally more stable than that on the stoichiometric surface, and it is more efficient in promoting further water dissociation upon heating. The results thus show how the presence of subsurface defects can alter the wetting mechanism of an oxide surface.

Oxidation and Reduction of TiOx Thin Films on Pd(111) and Pd(100)

Thin films of TiO_x on Pd(100) and Pd(111) have been investigated with respect to their properties after oxidation and reduction cycles. High-resolution photoemission spectroscopy (HRPES) and low energy electron diffraction (LEED) have been applied to characterize the thin film oxidation states and structure before and after oxidation and reduction under ultrahigh vacuum conditions. Fully oxidized TiO₂ films were formed on both surfaces. These structures display Moiré patterns in LEED, in one dimension for Pd(100) and in two dimensions for Pd(111), and they have previously not been reported for TiO₂/Pd. The oxidation process causes strong reduction in the interaction between the oxide thin film and the Pd substrate, most significantly for Pd(111). Reversible oxidation/reduction cycling of TiO_x thin films on Pd(111) and Pd(100) was possible.

Aortic coarctation - never too late to diagnose, never too late to treat

We present two cases of severe aortic coarctation detected in adulthood and who underwent successful relief by transcatheter stent deployment using a new covered stent, Optimus® stent (AndraTec GmbH Koblenz, Germany). One patient is a 46-year old female with resistant arterial hypertension, in whom coarctation was suspected on a follow-up transthoracic echocardiogram for bicuspid aortic valve disease and subsequently confirmed on magnetic resonance imaging. The second patient is a 68-year old male whose coarctation was diagnosed incidentally at coronary angiography being performed as part of the preoperative work-up for severe aortic stenosis. Suprasternal views to assess aortic arch and flows in the proximal descending aorta should be a standard part of every transthoracic echocardiogram. Treatment of aortic coarctation should be considered irrespective of patient's age.

The rarest aortic arch anomaly a case report of asymptomatic isolation of the subclavian artery

We present a rare case of isolated right subclavian artery arising from a right-sided patent arterial duct in a patient with DiGeorge syndrome, diagnosed on cardiac CT, along with potential complications and management approaches.

Photochemistry of Carboxylate on TiO2(110) Studied with Synchrotron Radiation Photoelectron Spectroscopy

We present a dedicated synchrotron radiation photoelectron spectroscopy (SR-PES) study of a photochemical reaction on the surface of rutile TiO₂(110). The photoreaction kinetics of carboxylate species (trimethyl acetate, TMA) upon irradiation by UV and soft X-rays were monitored, and we show that it is possible to control the reaction rates from UV light and soft X-rays independently. We directly observe Ti⁴⁺ → Ti³⁺ conversion upon irradiation, attributed to electron trapping at Ti sites close to surface OH groups formed by deprotonation of the parent molecule, trimethylacetic acid (TMAA). TMA photolysis on two surface preparations with different oxygen vacancy densities shows that the vacancy-related charge quenches the amount of charge that can be trapped at hydroxyls upon irradiation. During the initial stages of reaction the correlation between the amount of photodepleted TMA and the amount of charge trapped in the Ti 3d band gap state is nearly 1:1. A first-order kinetics analysis reveals that the reaction rate decreases with decreasing TMA coverage. There is also a coverage-dependent difference in the electronic structure of TMA moieties, primarily involving the carboxyl anchor group. These changes are consistent with a decreased hole affinity of the adsorbed TMA and hence a decreased reaction rate. This discovery adds to the previously presented picture of a reactivity that is inversely proportional to the number of surface hydroxyls, suggesting that the balance between the amounts of TMA, OH, and trapped charge needs to be considered.

Prevalence of obesity in Malta

Background

Obesity is a global epidemic with the Mediterranean island of Malta being no exception. The World Health Organization (WHO) has identified Malta as one of the European countries with the highest obesity prevalence.

Method

A cross‐sectional study was conducted (2014–2016) under the auspices of the University of Malta. The prevalence of overweight‐obesity in Malta was calculated and then age stratified for comparisons with previous studies.

Results

The study identified 69.75% (95% CI: 68.32–71.18) of the Maltese population to be either overweight or obese. The men overweight/obese prevalence (76.28% 95% CI: 74.41–78.14) was statistically higher than that for women (63.06% 95% CI: 60.92–65.20) (p = 0.0001). Age stratification revealed that both genders had the highest overweight prevalence rates between 55 and 64 years (Men = 23.25% 95% CI: 20.43–26.33; Women = 24.68% 95% CI: 21.44–28.22). Men obesity prevalence rates were highest in the 35 to 44 years group (22.52% 95% CI: 19.65–25.68) while for women it was highest in the 55 to 64 years group (28.90%, 95% CI: 25.44–30.63).

Conclusion

Over a 35‐year period, an overall decrease in the normal and overweight BMI categories occurred with an increase in the prevalence of obesity. An exception was observed in the women, where the prevalence of normal BMI increased over this time period. Also, it appears that while the total population obesity prevalence increased (for 2016), a percentage of the women have shifted from an obese to an overweight status.

Film-Screen Vs. Digital Radiography in Rheumatoid Arthritis of the Hand

In a prospective investigation the diagnostic accuracy of film-screen and digital radiography in rheumatoid arthritis of hands was compared. Seventy hands of 36 patients with established rheumatoid arthritis were included in the study. Each of 11 joints in every hand was evaluated regarding the following radiologic parameters: soft tissue swelling, joint space narrowing, erosions and periarticular osteopenia. The digital images were obtained with storage phosphor image plates and evaluated in 2 forms; as digital hard-copy on film and on a monitor of an interactive workstation. The digital images had a resolution of either 3.33 or 5.0 lp/mm. ROC curves were constructed and comparing the area under the curves no significant difference was found between the 3 different imaging forms in either resolution group for soft tissue swelling, joint space narrowing and erosions. The film-screen image evaluation of periarticular osteopenia was significantly better than the digital hard-copy one in the 3.33 lp/mm resolution group, but no significant difference was found in the 5.0 lp/mm group. These results support the view that currently available digital systems are capable of adequate diagnostic performance.

A high pressure x-ray photoelectron spectroscopy study of CO oxidation over Rh(100)

We have studied the oxidation of CO over Rh(100) using high pressure x-ray photoelectron spectroscopy under CO and O2 pressures ranging from 0.01 to 1 mbar. The results show a very low or no conversion for the CO covered surface found at low temperatures, while the activity rises slightly when the temperature is high enough for some CO to desorb, exposing surface sites for dissociative O2 adsorption. As the temperature is increased further, more CO desorbs and oxygen replaces CO as the dominating species at the surface. At the same time we find a sudden increase in the reactivity, such that all CO that reaches the surface is instantly transformed into CO2. We find that the O coverage in the active state is highly dependent on the total pressure and, although we do not detect any presence of a surface oxide as in previous surface x-ray diffraction studies, the highest O coverage indicates that the surface is close to being oxidized.

Increased decidual mRNA expression levels of candidate maternal pre-eclampsia susceptibility genes are associated with clinical severity

INTRODUCTION

Pre-eclampsia (PE) has a familial association, with daughters of women who had PE during pregnancy having more than twice the risk of developing PE themselves. Through genome-wide linkage and genetic association studies in PE-affected families and large population samples, we previously identified the following as positional candidate maternal susceptibility genes for PE; ACVR1, INHA, INHBB, ERAP1, ERAP2, LNPEP, COL4A1 and COL4A2. The aims of this study were to determine mRNA expression levels of previously identified candidate maternal pre-eclampsia susceptibility genes from normotensive and severe PE (SPE) pregnancies and correlate mRNA expression levels with the clinical severity of SPE.

METHODS

Third trimester decidual tissues were collected from both normotensive (n = 21) and SPE pregnancies (n = 24) and mRNA expression levels were determined by real-time PCR. Gene expression was then correlated with several parameters of clinical severity in SPE. Statistical significance was determined by Mann-Whitney U test and Spearman's Correlation.

RESULTS

The data demonstrate significantly increased decidual mRNA expression levels of ACVR1, INHBB, ERAP1, ERAP2, LNPEP, COL4A1 and COL4A2 in SPE (p < 0.05). Increased mRNA expression levels of several genes - INHA, INHBB, COL4A1 and COL4A2 were correlated with earlier onset of PE and earlier delivery of the fetus (p < 0.05).

CONCLUSION

These results suggest altered expression of maternal susceptibility genes may play roles in PE development and the course of disease severity.

In situ x-ray photoelectron spectroscopy of model catalysts: at the edge of the gap

We present high-pressure x-ray photoelectron spectroscopy (HP-XPS) and first-principles kinetic Monte Carlo study addressing the nature of the active surface in CO oxidation over Pd(100). Simultaneously measuring the chemical composition at the surface and in the near-surface gas phase, we reveal both O-covered pristine Pd(100) and a surface oxide as stable, highly active phases in the near-ambient regime accessible to HP-XPS. Surprisingly, no adsorbed CO can be detected during high CO(2) production rates, which can be explained by a combination of a remarkably short residence time of the CO molecule on the surface and mass-transfer limitations in the present setup.

A practical framework for data management processes and their evaluation in population-based medical registries

INTRODUCTION

We present a framework for data management processes in population-based medical registries. Existing guidelines lack the concreteness we deem necessary for them to be of practical use, especially concerning the establishment of new registries. Therefore, we propose adjustments and concretisations with regard to data quality, data privacy, data security and registry purposes.

MATERIALS AND METHODS

First, we separately elaborate on the issues to be included into the framework and present proposals for their improvements. Thereafter, we provide a framework for medical registries based on quasi-standard-operation procedures.

RESULTS

The main result is a concise and scientifically based framework that tries to be both broad and concrete. Within that framework, we distinguish between data acquisition, data storage and data presentation as sub-headings. We use the framework to categorise and evaluate the data management processes of a German cancer registry.

DISCUSSION

The standardisation of data management processes in medical registries is important to guarantee high quality of the registered data, to enhance the realisation of purposes, to increase efficiency and to enable comparisons between registries. Our framework is destined to show how one central impediment for such standardisations - lack of practicality - can be addressed on scientific grounds.

Bagging, bumping, multiview, and active learning for record linkage with empirical results on patient identity data

Record linkage or deduplication deals with the detection and deletion of duplicates in and across files. For this task, this paper introduces and evaluates two new machine-learning methods (bumping and multiview) together with bagging, a tree-based ensemble-approach. Whereas bumping represents a tree-based approach as well, multiview is based on the combination of different methods and the semi-supervised learning principle. After providing a theoretical background of the methods, initial empirical results on patient identity data are given. In the empirical evaluation, we calibrate the methods on three different kinds of training data. The results show that the smallest training data set, which is obtained by a simple active learning strategy, leads to the best results. Multiview can outperform the other methods only when all are calibrated on a randomly sampled training set; in all other cases, it performs worse. The results of bumping do not differ significantly from the overall best performing method bagging. We cautiously conclude that tree-based record linkage methods are likely to produce similar results because of the low-dimensionality (p≪n) and straightforwardness of the underlying problem. Multiview is possibly rather suitable for problems that are more sophisticated.

Missing values in deduplication of electronic patient data

INTRODUCTION

Systematic approaches to dealing with missing values in record linkage are still lacking. This article compares the ad-hoc treatment of unknown comparison values as 'unequal' with other and more sophisticated approaches. An empirical evaluation was conducted of the methods on real-world data as well as on simulated data based on them.

MATERIAL AND METHODS

Cancer registry data and artificial data with increased numbers of missing values in a relevant variable are used for empirical comparisons. As a classification method, classification and regression trees were used. On the resulting binary comparison patterns, the following strategies for dealing with missingness are considered: imputation with unique values, sample-based imputation, reduced-model classification and complete-case induction. These approaches are evaluated according to the number of training data needed for induction and the F-scores achieved.

RESULTS

The evaluations reveal that unique value imputation leads to the best results. Imputation with zero is preferred to imputation with 0.5, although the latter shows the highest median F-scores. Imputation with zero needs considerably less training data, it shows only slightly worse results and simplifies the computation by maintaining the binary structure of the data.

CONCLUSIONS

The results support the ad-hoc solution for missing values 'replace NA by the value of inequality'. This conclusion is based on a limited amount of data and on a specific deduplication method. Nevertheless, the authors are confident that their results should be confirmed by other empirical analyses and applications.

Adsorption of methylamine on Ni 3 Al(111) and NiAl(110)--a high resolution photoelectron spectroscopy and density functional theory study

Methylamine adsorption on the ordered Ni(3)Al(111) and NiAl(110) surfaces has been investigated by high resolution photoelectron spectroscopy and density functional theory calculations. Methylamine adsorbs molecularly at both surfaces at low temperature (90 K). The experiments show that methylamine interacts with the surface aluminium atoms on both surfaces, resulting in a positive binding energy shift relative to the Al 2p bulk contributions. A shift towards lower binding energy is also observed on NiAl(110) attributed to first and second layer surface Al atoms not bonded to methylamine. According to total energy calculations methylamine binds through its N atom to Al on-top sites on NiAl(110) while the Ni on-top site is found to be slightly preferred over the Al on-top site on Ni(3)Al(111). Calculated adsorbate induced shifts are, however, in good agreement with the experimental values only when methylamine is situated in the Al on-top site on both surfaces. In both cases, a lone pair bonding mechanism is found.

Evaluation of record linkage methods for iterative insertions

OBJECTIVES

There have been many developments and applications of mathematical methods in the context of record linkage as one area of interdisciplinary research efforts. However, comparative evaluations of record linkage methods are still underrepresented. In this paper improvements of the Fellegi-Sunter model are compared with other elaborated classification methods in order to direct further research endeavors to the most promising methodologies.

METHODS

The task of linking records can be viewed as a special form of object identification. We consider several non-stochastic methods and procedures for the record linkage task in addition to the Fellegi-Sunter model and perform an empirical evaluation on artificial and real data in the context of iterative insertions. This evaluation provides a deeper insight into empirical similarities and differences between different modelling frames of the record linkage problem. In addition, the effects of using string comparators on the performance of different matching algorithms are evaluated.

RESULTS

Our central results show that stochastic record linkage based on the principle of the EM algorithm exhibits best classification results when calibrating data are structurally different to validation data. Bagging, boosting together with support vector machines are best classification methods when calibrating and validation data have no major structural differences.

CONCLUSIONS

The most promising methodologies for record linkage in environments similar to the one considered in this paper seem to be stochastic ones.

CHEK2*1100delC is not an important high-risk gene in families with hereditary prostate cancer in southern Sweden

OBJECTIVE

CHEK2*1100delC is a frame-shifting germ-line mutation which abolishes the function of cell-cycle-checkpoint kinase 2 (chk2) and hence impairs the cells' response to DNA damage. This variant occurs in 1% of the general Western population but has been reported to be more common among patients with breast and prostate cancer. The aim of this study was to investigate the significance of CHEK2*1100delC as a possible high-risk gene for hereditary prostate cancer in the population of southern Sweden.

MATERIAL AND METHODS

We screened for the CHEK2*1100delC variant in 419 men diagnosed with prostate cancer in southern Sweden, 145 of whom were sporadic cases that were divided into two subgroups depending on whether they were diagnosed before (n=64) or after (n=81) the age of 55 years. A further 126 men were classified as familial prostate cancer cases and 148 as hereditary prostate cancer cases. The control group consisted of 305 military conscripts aged 18 years (range 18-21 years).

RESULTS

The CHEK2*1100delC variant was found in 1.2% of the cases (sporadic: 0.7%; familial: 1.6%; hereditary: 1.4%) and in 1.0% of the controls.

CONCLUSION

The CHEK2 1100delC mutation is not a clinically important high-risk gene for hereditary prostate cancer susceptibility in the population of southern Sweden.

The fabrication and characterization of PbTiO3 nanomesas realized on nanostructured SrRuO3/SrTiO3 templates

We report the fabrication of PbTiO(3) nanomesas down to 30 nm lateral size and 4 nm high on nanostructured SrRuO(3)/SrTiO(3) templates by off-axis radio frequency magnetron sputtering. The templates were prepared using a top-down lithography approach based on scanning tunneling microscopy. The growth rate of the PbTiO(3) nanomesas was found to decrease with increasing growth temperature as well as with shrinking template size. Piezoresponse force microscopy measurements for the PbTiO(3) nanomesas showed a strong increase in response with decreasing lateral size. A decrease of the coercive voltage was also observed for the same lateral size range. This laterally size-dependent behavior is attributed to reduction of in-plane strain, when shrinking the nanomesa lateral dimensions.