Newly developed dietary assessment tools for lutein and zeaxanthin are correlated with 24-hour diet recalls, but are not a valid measure of intake in Australian and United Kingdom adults

Habitual dietary intake measurement of carotenoids lutein and zeaxanthin (L/Z) has often been omitted or attempted with tools of unknown validity in past research. It was hypothesized that the dietary assessment tool, the L/Z screener, developed as part of this study, would be valid with agreement within 0.25 mg/day when compared against multiple 24-hour diet recalls in healthy Australian and United Kingdom adults. Two screeners with 91 food items were developed, 1 with a recall timeframe of a month and the other a week. Over 4 weeks, 56 Australian and 47 United Kingdom participants completed 4 weekly screeners, 2 monthly screeners, and eight 24-hour diet recalls. Validity was assessed through Bland-Altman plot analysis. L/Z intake measured by all tools was significantly correlated, with correlation coefficients from 0.58 to 0.83. Despite these correlations, the screeners were not valid, with poor Bland-Altman plot agreement when compared with the diet recalls. The Australian weekly screener performed best, demonstrating a mean difference of 0.51 mg/day and 95% limits of agreement between -1.46 mg/day and 2.49 mg/day of L/Z intake. Baby spinach, broccoli, and pumpkin provided the greatest proportion of L/Z intake. The low validity may be explained by high rates of misestimation or missed capture of moderate to high L/Z containing foods such as baby spinach. Prior research reliant on correlational statistics for L/Z tool validity should be interpreted with caution, and future screener development should prioritize accurate capture of high contribution foods.

Assessing electronic device use behaviours in healthy adults: development and evaluation of a novel tool

BACKGROUND

Chronic exposure of the macula to blue light from electronic devices has been identified as a potential macular health concern. The impacts remain poorly investigated as no validated methods to capture usual device use behaviours exist.

PURPOSE

The aim of this study was to develop and validate the Electronic Device Use Questionnaire (EDUQ) against multiple 24-h electronic device use diaries in healthy Australian and United Kingdom adults.

METHODS

The EDUQ and diaries were developed to capture device use across categories (television, computer and handheld devices). Over eight weeks 56 Australian and 24 United Kingdom participants completed three questionnaires and eight diaries via online platforms. Tool validity was determined through Bland-Altman plot analysis of mean daily hours of device use between the tools.

RESULTS

The EDUQ demonstrated poor validity in both cohorts with poor agreement when compared with the diaries. When the device categories were combined, a mean difference between the tools of 1.54 h/day, and 95% limits of agreement between -2.72 h/day and 5.80 h/day was observed in the Australian cohort. Across both cohorts and all device categories the mean differences indicated individuals were more likely to report higher device use through the questionnaire rather than diaries.

CONCLUSIONS

The EDUQ is a novel tool and demonstrated the difficulty for participants of accurately recalling usual behaviour of device use. Poor agreement in reported device use occurred across all device categories. The poor agreement may be related to factors such as memory recall bias, and the number of diaries captured not being reflective of usual use. Future studies should look to address these factors to improve validity of device use capture.

OGC P28 Raman Needle Probe Lymph Node Assessment for Oesophageal Cancer: The DOLOMITE Study

Background

Oesophageal cancer (OC) accounts for 3% of all new cancer diagnosis in the UK. Presentation is often late, reflected in a poor 5-year survival rate of 12%. The importance of identifying lymph node (LN) metastases has been demonstrated as the single biggest prognostic factor.

The current ‘gold standard’ diagnosis of LN metastases is from histopathological assessment of the tissue after surgical resection of the primary tumour and surrounding tissue. The use of imaging techniques to try and gain this information preoperatively is standard practice but far from perfect.

Raman spectroscopy (RS) has been investigated as a diagnostic tool to detect cancer and pre-cancerous change in the oesophagus, and preliminary work demonstrating the application of vibrational spectroscopy (Raman and FTIR) to LN analysis has been undertaken. The development of Raman needle probes (RNP) with potential for use in-vivo furthers the clinical impact.

The DOLOMITE study started recruitment in the summer of 2022 to investigate the ability of RNP to identify the presence of malignant deposits in resected lymph nodes.

Methods

Patients identified by the clinical team as needing oesophagectomy to treat their OC were invited to participate in the study. After the specimen has been resected, prior to formalin fixation, three lymph nodes are dissected representing gastric, para-oesophageal and sub-carinal nodes. These are bisected longitudinally with half remaining with the specimen. The half for research is snap frozen in liquid nitrogen until needed for analysis.

Adjacent sections are cut from the nodes to create slides for Raman mapping and conventional H&E staining. The bulk node left is used for Raman probe analysis. Spectral data is then analysed using MATlab.

Results

At this early stage, our initial measurements have provided information used for calibration in advance of completing recruitment. The Raman mapping has been assessed for correlation with the pathology identified in the H&E slides taken from the lymph node block. This data in turn has provided the background for developing interpretation of the Raman probe data, with further samples we will use this to create a classification model.

Conclusions

With ongoing recruitment the study will be able to fully report by September 2023.

References

1. Stone N, Kendall C, Shepherd N, Crow P, Barr H Near-infrared Raman spectroscopy for the classification of epithelial pre-cancers and cancers 2002 33(7):564–573

2. Kong K, Kendall C, Stone N, Notingher I. Raman spectroscopy for medical diagnostics--From in-vitro biofluid assays to in-vivo cancer detection. Adv Drug Deliv Rev. 2015;89:121–34.

An exploratory study of the relationship between systemic microcirculatory function and small solute transport in incident peritoneal dialysis patients

BACKGROUND

The peritoneal capillary endothelium is widely considered to be the most influential structure in dictating the rate of small solute transport (SST) during peritoneal dialysis (PD). PD patients are at significant risk of systemic microcirculatory dysfunction. The relationship between peritoneal and systemic microcirculations in patients new to PD has not been well studied. We hypothesised that for patients on PD for less than 6 months, dysfunction in the systemic microcirculation would be reflected in the rate of SST.

METHODS

We recruited 29 patients to a cross-sectional, observational study. Rate of SST was measured using a standard peritoneal equilibration test. Laser Doppler Flowmetry was used to measure response to physical and pharmacological challenge (post-occlusive hyperaemic response and iontophoretic application of vasodilators) in the cutaneous microcirculation. Sidestream Darkfield imaging was used to assess sublingual microvascular density, flow and endothelial barrier properties.

RESULTS

We found no moderate or strong correlations between any of the measures of systemic microcirculatory function and rate of SST or albumin clearance. There was however a significant correlation between dialysate interleukin-6 concentrations and both SST (r_s = 0.758 p ≤ 0.0001) and albumin clearance (r_s = 0.53, p = 0.01).

CONCLUSIONS

In this study, systemic microvascular dysfunction did not significantly influence the rate of SST even early in patients PD careers. In conclusion, this study demonstrates that intraperitoneal factors particularly inflammation have a far greater impact on rate of SST than systemic factors.

24-h Glycaemic profiles in peritoneal dialysis patients and non-dialysis controls with advanced kidney disease

BACKGROUND

For patients on peritoneal dialysis (PD), the deleterious effects of high concentrations of dialysate glucose on the peritoneal membrane are well-documented. Systemic effects of peritoneally absorbed glucose are more poorly defined. Using continuous glucose monitoring (CGM), we aimed to describe 24-h glycaemic profiles of PD patients without diabetes and compare with non-dialysis controls with stage 5 chronic kidney disease (CKD-5).

METHODS

In this cross-sectional, case-control study, 15 patients on PD (9 automated PD (APD) and 6 continuous ambulatory PD (CAPD)) and 16 CKD-5 controls underwent 72 h of CGM and metabolic profiling. CGM was used to derive average glucose concentrations and within-participant standard deviation (SD) of glucose. Data were analysed for the whole 72-h monitoring period and as daytime (09.00 to 21.00) and night-time (21.00 to 09.00).

RESULTS

Average glucose concentrations and within-participant SD of glucose for the whole monitoring period were not different between the three groups (p ≥ 0.5). Daytime average glucose concentrations were also similar across the three groups (p = 0.729). APD was associated with a significantly higher nocturnal glucose than CAPD (5.25 mmol/L ± 0.65 vs. 4.28 ± 0.5, p = 0.026). A significant drop in nocturnal glucose compared with daytime average seen in both CAPD patients and controls was absent in APD patients.

CONCLUSIONS

Systematically different glycaemic patterns were observed in non-diabetic APD and CAPD patients, including an absence of physiological nocturnal glucose dipping in patients on APD. Comprehensive CGM data sets highlight subtleties not appreciated by traditional metabolic biomarkers; this has implications when choosing the most appropriate outcome measures in future research addressing the metabolic impact of PD.

An appraisal of trials investigating the effects on macular pigment optical density of lutein and zeaxanthin dietary interventions: a narrative review

Lutein and zeaxanthin (L/Z), xanthophylls obtained from the diet, are deposited in the macula of the eye. The macular concentration of L/Z is quantifiable as macular pigment optical density (MPOD). The aim of this review was to critically appraise the effect on MPOD of increasing L/Z intake by dietary intervention in adults. Pubmed, Cochrane Library, Web of Science, and Cinahl were searched up to April 2020. Ten studies investigating populations with and without age-related macular degeneration were included. MPOD increased significantly in 2 of the 8 controlled studies. Studies varied largely in the prescribed dietary L/Z dosage, duration, and participant characteristics. No relationships between types of dietary L/Z interventions and MPOD response could be determined. Limited monitoring of habitual dietary L/Z intake was identified as a major limitation of all 10 studies. Habitual dietary L/Z intake should be closely monitored in future studies to account for their effects on MPOD response to dietary L/Z interventions.

Effects of exenatide on microvascular reactivity in patients with type 2 diabetes and coronary artery disease: A randomized controlled study

OBJECTIVE

We studied the effect of the GLP-1RA exenatide on skin microvascular function in patients with T2DM and CAD.

METHODS

Thirty-five patients with T2DM, CAD, and HbA1C 42-86 mmol/mol were randomized to treatment with exenatide or conventional non-GLP-1-based therapy for 12 weeks. Skin microvascular function was examined in the forearm by LDF and iontophoretic application of acetyl choline and SNP, and by PORH at baseline and after 12 weeks. Blood samples for fasting plasma glucose, HbA1C, and lipid profile were collected.

RESULTS

At 12 weeks, patients on exenatide showed reductions in HbA1C (from 63.5 ± 13 to 60.7 ± 14 mmol/mol, p = .065), body weight (from 92.6 ± 16 to 89 ± 16 kg, p < .001), and systolic blood pressure (from 141 ± 13 to 134 ± 16 mm Hg, p < .05) as compared to the conventionally treated group. There were no significant changes in skin microvascular function between or within the two groups at follow-up.

CONCLUSIONS

Three months' daily treatment with the GLP-1RA exenatide in T2DM patients with CAD showed no significant effects on skin microvascular function or blood glucose control, while this study confirms a reduction in body weight and blood pressure by exenatide, as compared to conventional antidiabetic drug treatment.

Urinary nitrate concentration as a marker for kidney transplant rejection

BACKGROUND

Early identification and treatment of kidney transplant rejection episodes is vital to limit loss of function and prolong the life of the transplanted kidney and recipient. Current practice depends on detecting a creatinine rise. A biomarker to diagnose transplant rejection at an earlier time point than current practice, or to inform earlier decision making to biopsy, could be transformative. It has previously been shown that urinary nitrate concentration is elevated in renal transplant rejection. Nitrate is a nitric oxide (NO) oxidation product. Transplant rejection upregulates NO synthesis via inducible nitric oxide synthase leading to elevations in urinary nitrate concentration. We have recently validated a urinary nitrate concentration assay which could provide results in a clinically relevant timeframe. Our aim was to determine whether urinary nitrate concentration is a useful tool to predict renal transplant rejection in the context of contemporary clinical practice.

METHODS

We conducted a prospective observational study, recruiting renal transplant participants over an 18-month period. We made no alterations to the patients' clinical care including medications, immunosuppression, diet and frequency of visits. We collected urine samples from every clinical attendance. We assessed the urinary nitrate to creatinine ratio (uNCR) between patient groups: routine attendances, biopsy proven rejection, biopsy proven no rejection and other call backs. uNCR was examined over time for those with biopsy proven transplant rejection. These four groups were compared using an ANOVA test.

RESULTS

A total of 2656 samples were collected. uNCR during biopsy proven rejection, n = 15 (median 49 μmol/mmol, IQR 23-61) was not significantly different from that of routine samples, n = 164 (median 55 μmol/mmol, IQR 37-82) (p = 0.55), or biopsy proven no rejection, n = 12 (median 39 μmol/mmol, IQR 21-89) (P = 0.77). Overall uNCR was highly variable with no diagnostic threshold for kidney transplant rejection. Furthermore, within-patient uNCR was highly variable over time, and thus it was not possible to produce individualised patient thresholds to identify rejection. The total taking Tacrolimus was 204 patients, with no statistical difference between the uNCR of all those on Tacrolimus, against those not, p = 0.18.

CONCLUSION

The urinary nitrate to creatinine ratio is not a useful biomarker for renal transplant rejection.

P1612CAN THE URINARY NITRATE TO CREATININE RATIO BE USED AS A MARKER FOR KIDNEY TRANSPLANT REJECTION?

Background and Aims

Early identification and treatment of kidney transplant rejection episodes is vital to limit loss of function and prolong the life of the transplanted kidney and recipient. Current practice depends on detecting a creatinine rise. A biomarker to diagnose transplant rejection, either at an earlier time point, or to inform earlier decision making to biopsy, could be transformative. Urinary nitrate concentration is elevated in renal transplant rejection. Nitrate is a nitric oxide (NO) oxidation product. Transplant rejection upregulates NO synthesis via inducible nitric oxide synthase leading to elevations in urinary nitrate concentration. Historically, assays for measurement of inorganic nitrate in biological fluids have been too time consuming to be useful in a clinical setting. We have recently validated a urinary nitrate concentration assay which could provide results in a clinically relevant timeframe. Our aim was to determine whether urinary nitrate concentration is a useful tool to predict renal transplant rejection in the context of contemporary clinical practice.

Method

We conducted a prospective observational study, recruiting renal transplant participants over an 18 month period. We made no alterations to the patients’ clinical care including medications, immunosuppression, diet and frequency of visits. We collected urine samples from every clinical attendance including routine attendances, unscheduled attendances for acute clinical indications, and on the day of attendance for biopsy, for those who underwent biopsy. We measured the urinary nitrate to creatinine ratio (uNCR) between patient groups including routine attendances, biopsy proven rejection and biopsy proven “no rejection”. uNCR was examined over time for those with transplant rejection. Groups were compared using a 2 tail t-test of unequal variance, for statistical significance.

Results

A total of 2656 samples were collected. uNCR during biopsy proven rejection, median 49 µmol/mmol, IQR 23-61, was not significantly different from that of routine samples, median 55 µmol/mmol, IQR 37-82 (p=0.56), or biopsy proven “no rejection”, median 39 µmol/mmol, IQR 21-89, (P=0.77). Overall uNCR was highly variable; median 52 µmol/mmol, IQR 31-81, with no diagnostic threshold for kidney transplant rejection. Furthermore, within-patient uNCR was highly variable over time, and thus it was not possible to produce individualised patient thresholds to identify rejection.

Conclusion

The urinary nitrate to creatinine ratio is not a useful biomarker for renal transplant rejection.

P1161CUTANEOUS MICROCIRCULATORY DYSFUNCTION IN PERITONEAL DIALYSIS PATIENTS

Background and Aims

Microvascular impairment is an early step in cardiovascular disease (CVD), the major cause of morbidity and mortality in patients with CKD. Changes in skin microvascular reactivity have been shown to reflect more widespread changes in the systemic and coronary microcirculation. Microvascular function is attenuated by advancing age and conditions that commonly coexist with CKD such as diabetes and hypertension. We investigated whether skin microvascular reactivity is impaired in peritoneal dialysis (PD) patients compared with healthy controls and whether this impairment is independent of comorbidity.

Method

Forearm skin vasculature was examined in 27 healthy controls, 27 patients on PD and 27 controls matched to the PD patients for age, gender, diabetes and previous CV events. Microvascular function was assessed using laser Doppler flowmetry in combination with post-occlusive reactive hyperaemia (a test of generalised microvascular function) and iontophoretic application of acetylcholine (ACh) and sodium nitroprusside (SNP) to investigate endothelium dependant and non-endothelium dependant vasodilation respectively.

Results

Peak post-occlusive flow was lower in the PD patients than in both the healthy controls and the co-morbidity matched group; 90.45 AU (60.9-128.35) in healthy controls, 73AU (58.8-134.4) in matched controls and 56.95AU (45.1-89.8) in PD patients (p=0.0239 healthy controls versus patients, p=0.0373 matched controls versus patients). SNP-mediated vasodilatation was statistically lower in the PD group compared with healthy controls (p= 0.016), ACh response was lower but did not reach statistical significance (p= 0.076). ACh and SNP-mediated vasodilatation trended towards being lower in PD patients than matched controls but did not reach statistical significance.

Conclusion

The PD patients were characterised by a generalised dysfunction of the skin microcirculation compared with healthy controls and controls matched for factors known to affect the microcirculation. This appears to be the result of impaired endothelium dependant and independent vasodilatory mechanisms.

Raman spectroscopy for rapid intra-operative margin analysis of surgically excised tumour specimens

Raman spectroscopy, a form of vibrational spectroscopy, has the ability to provide sensitive and specific biochemical analysis of tissue. This review article provides an in-depth analysis of the suitability of different Raman spectroscopy techniques in providing intra-operative margin analysis in a range of solid tumour pathologies. Surgical excision remains the primary treatment of a number of solid organ cancers. Incomplete excision of a tumour and positive margins on histopathological analysis is associated with a worse prognosis, the need for adjuvant therapies with significant side effects and a resulting financial burden. The provision of intra-operative margin analysis of surgically excised tumour specimens would be beneficial for a number of pathologies, as there are no widely adopted and accurate methods of margin analysis, beyond histopathology. The limitations of Raman spectroscopic studies to date are discussed and future work necessary to enable translation to clinical use is identified. We conclude that, although there remain a number of challenges in translating current techniques into a clinically effective tool, studies so far demonstrate that Raman Spectroscopy has the attributes to successfully perform highly accurate intra-operative margin analysis in a clinically relevant environment.

The oral cavity revealed as a significant reservoir of Staphylococcus aureus in an acute hospital by extensive patient, healthcare worker and environmental sampling

BACKGROUND

Methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infection rates have risen steadily in recent years, with a marked decline in the corresponding rates due to methicillin-resistant S. aureus (MRSA). Screening for MSSA carriage is not routinely undertaken and MRSA screening is not universal, so the extent of S. aureus colonisation pressure in nosocomial settings is unknown.

METHODS

We conducted a prospective, observational study of patients and healthcare workers (HCWs) across nine inpatient wards in a tertiary referral hospital over a two-year period. Participants were screened for MSSA and MRSA using nasal swabs and oral rinses. Environmental surfaces and air were also tested for S. aureus using contact plates and active air sampling.

FINDINGS

We enrolled 388 patients and 326 HCWs; and took 758 contact plate samples from surfaces and 428 air samples. MSSA was recovered from 24% of patients, 31.3% of HCWs, 16% of air samples and 7.9% of surface samples. MRSA was recovered from 6.4% of patients, 3.7% of HCWs, 2.5% of air samples and 2.2% of surface samples. Inclusion of the oral cavity in addition to the anterior nares in the sampling regimen identified 30 patients and 36 HCWs who exhibited exclusive oral colonisation.

CONCLUSIONS

The oral cavity comprises a significant nosocomial reservoir for S. aureus that is currently under-appreciated. Oral screening should be considered both in terms of the colonisation pressure in a healthcare facility, and on an individual patient level, especially in patients where decolonisation attempts have repeatedly failed and those undergoing high risk procedures.

The systemic microcirculation in dialysis populations

In a rapidly expanding population of patients with chronic kidney disease, including 2 million people requiring renal replacement therapy, cardiovascular mortality is 15 times greater than the general population. In addition to traditional cardiovascular risk factors, more poorly defined risks related to uremia and its treatments appear to contribute to this exaggerated risk. In this context, the microcirculation may play an important early role in cardiovascular disease associated with chronic kidney disease. Experimentally, the uremic environment and dialysis have been linked to multiple pathways causing microvascular dysfunction. Coronary microvascular dysfunction is reflected in remote and more easily studied vascular beds such as the skin. There is increasing evidence for a correlation between systemic microvascular dysfunction and adverse cardiovascular outcomes. Systemic microcirculatory changes have not been extensively investigated across the spectrum of chronic kidney disease. Recent advances in non-invasive techniques studying the microcirculation in vivo in man are increasing the data available particularly in patients on hemodialysis. Here, we review current knowledge of the systemic microcirculation in dialysis populations, explore whether non-invasive techniques to study its function could be used to detect early stage cardiovascular disease, address challenges faced in studying this patient cohort and identify potential future avenues for research.

3043Endotrophin, a fragment of collagen type VI, is correlated to IMT and associated with cardiovascular events in patients with atherosclerosis and diabetes: the IMI-SUMMIT cohort

Background/Introduction

Patients with micro- and macrovascular diseases, including atherosclerosis, have increased risk of cardiovascular events and early mortality. The atherosclerotic disease is characterised by accumulation of lipids, cells and proteins in the arterial wall, which includes remodelling of the extracellular matrix (ECM). Collagen type VI (COL6) is known to be over-expressed in patients with atherosclerosis. The biomarker PRO-C6, known as endotrophin, is a COL6 fragment that reflects formation of collagen type VI, and possess pro-inflammatory and pro-fibrotic activities.

Purpose

We explored whether increased endotrophin levels, measured by PRO-C6, were associated with intima-media thickness (IMT) and mortality in the IMI-SUMMIT cohort.

Methods

Circulating protein levels of PRO-C6 were measured in EDTA plasma from 1500 patients enrolled at four European University Hospitals, using an enzyme-linked immunosorbent assay. Follow-up data were available up to three years after sample collection. Associations between PRO-C6 and incidence of cardiovascular (CV) events and all-cause mortality were assessed by Kaplan-Meier curves and Cox proportional hazard regression analyses. Pearson correlation was performed to explore the association of PRO-C6, IMT and clinical variables. Known confounders defined by the Framingham Heart study (age, gender and diabetes) were included in the Cox proportional hazard regression analysis.

Results

Plasma PRO-C6 was significantly correlated with IMT in both the common carotid artery and the carotid bulb (r=0.09, p=0.002 and r=0.11, p=0.0003, respectively), HbA1c (r=0.11, p<0.0001) and C-reactive protein (r=0.14, p<0.0001). A total of 145 patients suffered from fatal or non-fatal cardiovascular events during the three-year follow-up period. Patients in the highest PRO-C6 tertile had a two-fold increased risk of experiencing a CV event during follow-up (p=0.002), independently of age, presence of CVD at baseline, type 2 diabetes, smoking and statin treatment in a regression model.

Conclusion

The present findings demonstrate that circulating levels of PRO-C6 are associated with atherosclerosis severity and increased incidence of cardiovascular events. Since PRO-C6 detects the signaling molecule endotrophin, the results may indicate that endotrophin is not only a biomarker of atherosclerotic disease, but may have a role in promoting disease progression.

Acknowledgement/Funding

This work was supported by the Danish Research Foundation, The Danish innovation foundation and the IMI-SUMMIT participants

Automated cytological detection of Barrett's neoplasia with infrared spectroscopy

BACKGROUND

Development of a nonendoscopic test for Barrett's esophagus would revolutionize population screening and surveillance for patients with Barrett's esophagus. Swallowed cell collection devices have recently been developed to obtain cytology brushings from the esophagus: automated detection of neoplasia in such samples would enable large-scale screening and surveillance.

METHODS

Fourier transform infrared (FTIR) spectroscopy was used to develop an automated tool for detection of Barrett's esophagus and Barrett's neoplasia in esophageal cell samples. Cytology brushings were collected at endoscopy, cytospun onto slides and FTIR images were measured. An automated cell recognition program was developed to identify individual cells on the slide.

RESULTS

Cytology review and contemporaneous histology was used to inform a training dataset containing 141 cells from 17 patients. A classification model was constructed by principal component analysis fed linear discriminant analysis, then tested by leave-one-sample-out cross validation. With application of this training model to whole slide samples, a threshold voting system was used to classify samples according to their constituent cells. Across the entire dataset of 115 FTIR maps from 66 patients, whole samples were classified with sensitivity and specificity respectively as follows: normal squamous cells 79.0% and 81.1%, nondysplastic Barrett's esophagus cells 31.3% and 100%, and neoplastic Barrett's esophagus cells 83.3% and 62.7%.

CONCLUSIONS

Analysis of esophageal cell samples can be performed with FTIR spectroscopy with reasonable sensitivity for Barrett's neoplasia, but with poor specificity with the current technique.

Mirror energy differences at large isospin studied through direct two-nucleon knockout

The first spectroscopy of excited states in 52Ni (T(z)=-2) and 51Co (T(z)=-3/2) has been obtained using the highly selective two-neutron knockout reaction. Mirror energy differences between isobaric analogue states in these nuclei and their mirror partners are interpreted in terms of isospin nonconserving effects. A comparison between large-scale shell-model calculations and data provides the most compelling evidence to date that both electromagnetic and an additional isospin nonconserving interactions for J=2 couplings, of unknown origin, are required to obtain good agreement.

Effect of dietary nitrate on blood pressure, endothelial function, and insulin sensitivity in type 2 diabetes

Diets rich in green, leafy vegetables have been shown to lower blood pressure (BP) and reduce the risk of cardiovascular disease. Green, leafy vegetables and beetroot are particularly rich in inorganic nitrate. Dietary nitrate supplementation, via sequential reduction to nitrite and NO, has previously been shown to lower BP and improve endothelial function in healthy humans. We sought to determine if supplementing dietary nitrate with beetroot juice, a rich source of nitrate, will lower BP and improve endothelial function and insulin sensitivity in individuals with type 2 diabetes (T2DM). Twenty-seven patients, age 67.2±4.9 years (18 male), were recruited for a double-blind, randomized, placebo-controlled crossover trial. Participants were randomized to begin, in either order, a 2-week period of supplementation with 250ml beetroot juice daily (active) or 250ml nitrate-depleted beetroot juice (placebo). At the conclusion of each intervention period 24-h ambulatory blood pressure monitoring, tests of macro- and microvascular endothelial function, and a hyperinsulinemic isoglycemic clamp were performed. After 2 weeks administration of beetroot juice mean ambulatory systolic BP was unchanged: 134.6±8.4mmHg versus 135.1±7.8mmHg (mean±SD), placebo vs active-mean difference of -0.5mmHg (placebo-active), p=0.737 (95% CI -3.9 to 2.8). There were no changes in macrovascular or microvascular endothelial function or insulin sensitivity. Supplementation of the diet with 7.5mmol of nitrate per day for 2 weeks caused an increase in plasma nitrite and nitrate concentration, but did not lower BP, improve endothelial function, or improve insulin sensitivity in individuals with T2DM.

Unique Blood Pressure Characteristics in Mother and Offspring After Early Onset Preeclampsia

Risk of hypertension in mother and offspring after preeclampsia is greater if preeclampsia develops early in pregnancy. We investigated whether those who develop early onset disease have unique adverse blood pressure characteristics. One hundred forty women were studied 6 to 13 years either after a pregnancy complicated by preeclampsia (45 women with early onset preeclampsia before 34 weeks gestation and 45 women with late-onset preeclampsia) or after a normotensive pregnancy (50 women). Forty-seven offspring from these pregnancies also participated. Data on maternal antenatal and postnatal blood pressures were extracted from maternity records and related to peripheral, central, and ambulatory blood pressure measurements in later life. Compared with late-onset preeclampsia, early onset preeclampsia was associated with higher diastolic blood pressure 6 weeks postnatally (86.25±13.46 versus 75.00±5.00 mm Hg, P <0.05), a greater increase in blood pressure relative to booking blood pressure over the subsequent 6 to 13 years, and higher nocturnal systolic and diastolic blood pressures in later life (111.07±13.18 versus 101.13±11.50 mm Hg, P =0.04, and 67.00±7.25 versus 58.60±5.79 mm Hg, P =0.002). Furthermore, at age 6 to 13 years their offspring had higher systolic blood pressure compared with those born to late-onset preeclampsia (96.27±7.30 versus 88.39±7.57 mm Hg, P =0.005). Mothers who developed early onset preeclampsia, and the offspring of that pregnancy display specific adverse blood pressure characteristics later in life. These are not evident in mothers and offspring after late-onset preeclampsia or normotensive pregnancy.

Exfoliated colonocyte DNA levels and clinical features in the diagnosis of colorectal cancer: a cohort study in patients referred for investigation

AIM

Selection of patients for investigation of suspected colorectal cancer is difficult. One possible improvement may be to measure DNA isolated from exfoliated cells collected from the rectum.

METHOD

This was a cohort study in a surgical clinic. Participants were aged ≥40 years and referred for investigation of suspected colorectal cancer. Exclusion criteria were inflammatory bowel disease, previous gastrointestinal malignancy, or recent investigation. A sample of the mucocellular layer of the rectum was taken with an adapted proctoscope (the Colonix system). Haemoglobin, mean cell volume, ferritin, carcino-embryonic antigen and faecal occult bloods were tested. Analysis was by logistic regression.

RESULTS

Participation was offered to 828 patients, of whom 717 completed the investigations. Three were lost to follow up. Seventy-two (10%) had colorectal cancer. Exfoliated cell DNA was higher (P<0.001) in cancer (median 5.4 μg/ml [inter-quartile range 1.8,12]) compared with those without cancer (2.0 μg/ml [IQR 0.78,5.5]). Seven variables were independently associated with cancer, including age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.02,1.08; P<0.001) DNA (OR, 1.05; CI, 1.01,3.6; P=0.01), mean cell volume (OR, 0.93; CI, 0.89,0.97; P=0.001), carcino-embryonic antigen 1.02 per μg/l (CI, 1.00,1.04; P=0.02), male sex (OR, 2.0; CI, 1.1,3.6; P=0.02), rectal bleeding (OR, 2.4; CI, 1.3,4.5; P=0.007) and positive faecal occult blood (OR, 6.7; CI, 3.4, 13; P<0.001). The area under the receiver-operating characteristic curve for the DNA score was 0.65 (0.58-0.72) and for the seven variable model 0.88 (CI, 0.84-0.92).

CONCLUSION

Quantification of exfoliated DNA from rectal cellular material has promise in the diagnosis of colorectal cancer, but this requires confirmation in a larger study.

Role of Ucp1 enhancer methylation and chromatin remodelling in the control of Ucp1 expression in murine adipose tissue

AIMS/HYPOTHESIS

Increasing the expression of the brown adipose tissue-specific gene uncoupling protein-1 (Ucp1) is a potential target for treating obesity. We investigated the role of DNA methylation and histone modification in Ucp1 expression in adipose cell lines and ex vivo murine adipose tissues.

METHODS

Methylation state of the Ucp1 enhancer was studied using bisulphite mapping in murine adipose cell lines, and tissue taken from cold-stressed mice, coupled with functional assays of the effects of methylation and demethylation of the Ucp1 promoter on gene expression and nuclear protein binding.

RESULTS

We show that demethylation of the Ucp1 promoter by 5-aza-deoxycytidine increases Ucp1 expression while methylation of Ucp1 promoter-reporter constructs decreases expression. Brown adipose tissue-specific Ucp1 expression is associated with decreased CpG dinucleotide methylation of the Ucp1 enhancer. The lowest CpG dinucleotide methylation state was found in two cyclic AMP response elements (CRE3, CRE2) in the Ucp1 promoter and methylation of the CpG in CRE2, but not CRE3 decreased nuclear protein binding. Chromatin immunoprecipitation assays revealed the presence of the silencing DiMethH3K9 modification on the Ucp1 enhancer in white adipose tissue and the appearance of the active TriMethH3K4 mark at the Ucp1 promoter in brown adipose tissue in response to a cold environment.

CONCLUSIONS/INTERPRETATION

The results demonstrate that CpG dinucleotide methylation of the Ucp1 enhancer exhibits tissue-specific patterns in murine tissue and cell lines and suggest that adipose tissue-specific Ucp1 expression involves demethylation of CpG dinucleotides found in regulatory CREs in the Ucp1 enhancer, as well as modification of histone tails.

Platelet and leukocyte activation, atherosclerosis and inflammation in European and South Asian men

BACKGROUND

Increased platelet activation occurs in ischemic heart disease (IHD), but increased platelet activation is also seen in cerebrovascular atherosclerosis and peripheral artery disease. It is not clear therefore whether platelet activation is an indicator of IHD or a marker of generalized atherosclerosis and inflammation. South Asian subjects are at high risk of IHD, but little is known regarding differences in platelet and leukocyte function between European and South Asian subjects.

METHODS

Fifty-four male subjects (age 49-79 years) had coronary artery calcification measured by multislice computed tomography (CT), aortic atherosclerosis assessed by measurement of carotid-femoral pulse wave velocity (aortic PWV), and femoral and carotid atherosclerosis measured by B-mode ultrasound. Platelet and leukocyte activation was assessed by flow cytometry of platelet-monocyte complexes (PMC), platelet expression of PAC-1 binding site and CD62P, and expression of L-selectin on leukocytes.

RESULTS

Elevated circulating PMC correlated significantly with elevated aortic PWV and PMC were higher in subjects with femoral plaques. In contrast PMC did not differ by increasing coronary artery calcification category or presence of carotid plaques. Higher numbers of PMC were independently related to elevated levels of C-reactive protein (CRP), higher aortic PWV, hypertension and smoking in a multivariate model. Markers of platelet and leukocyte activation did not differ significantly by ethnicity.

CONCLUSIONS

Increased PMC are related to the extent of aortic and femoral atherosclerosis rather than coronary or carotid atherosclerosis. The association between elevated CRP and increased PMC suggests that inflammation in relation to generalized atherosclerosis may play an important role in PMC activation.

Measurement of pulse wave velocity: site matters

BACKGROUND

Aortic pulse wave velocity (PWV) predicts mortality from cardiovascular disease, ischaemic heart disease and stroke. However, a comparison of associations between PWV measured at different sites and atherosclerosis in coronary, carotid and femoral arteries has not been made.

METHODS

In 159 men (ages 45-82 years) with and without known coronary artery disease, PWV measurements were made between carotid-femoral, carotid-radial and femoral-posterior tibial sites, using an ultrasound technique. Coronary artery calcification (CAC) scores were measured by multislice computed tomography. Carotid and femoral intima-media thickness (IMT) and presence of plaque were determined by ultrasound. Known coronary artery disease was confirmed by angiography. Participants were grouped into four categories of CAC score: 0-10, 11-100, 101-400, > 400 Hounsfield Units (HU). Measurements of blood pressure, heart rate and fasting bloods were made in all individuals.

RESULTS

Carotid-femoral PWV correlated positively with CAC score and increased with incremental coronary calcification category (median carotid-femoral PWV 16.8 m/s in those with CAC score > 400 HU and 13.8 m/s in those with CAC score < 10 HU; P = 0.003). Carotid-femoral PWV also correlated with carotid and femoral IMT (P < 0.001, P = 0.004, respectively) and with carotid and femoral plaque (P = 0.001, P = 0.038, respectively). Increased carotid-femoral PWV also correlated with increasing age (P < 0.001), systolic blood pressure (P < 0.001), mean arterial pressure and pulse pressure (P < 0.001). Carotid-radial and femoral-posterior tibial PWV were not significantly associated with CAC score, carotid or femoral IMT or carotid plaque.

CONCLUSIONS

Carotid-femoral PWV is a better indicator of atherosclerosis than either carotid-radial or femoral-posterior tibial PWV, and should be used preferentially in studies of atherosclerosis and in stratifying risk in clinical settings.

Epidemiological typing of MRSA isolates from blood cultures taken in Irish hospitals participating in the European Antimicrobial Resistance Surveillance System (1999-2003)

Between 1999 and 2003, meticillin-resistant Staphylococcus aureus (MRSA) isolates recovered from blood cultures in Irish hospitals that participate in the European Antimicrobial Resistance Surveillance System were investigated by epidemiological typing using antibiogram-resistogram (AR) typing, biotyping, and DNA macrorestriction digestion using SmaI followed by pulsed-field gel electrophoresis (PFGE). PFGE patterns were assigned five-digit pulsed-field type (PFT) numbers, and PFTs of apparently related patterns were abbreviated to two-digit PFT groups (PFGs). AR and PFGE typing results were combined to produce AR-PFG types. Representative isolates of each AR-PFG type recovered in 2002 were typed by multilocus sequence typing and staphylococcal cassette chromosome (SCC) mec analysis. Isolates from 1999 and 2000 were also typed by phage typing. The extent to which epidemiological types of MRSA from blood cultures could be extrapolated to the total MRSA population was investigated by comparing results obtained with isolates from the total MRSA population versus those obtained with blood cultures during three study periods. Over the 5 years from 1999 to 2003, 1,580 blood culture isolates from 1,495 patients were analysed. Typeability and discriminatory indices were as follows: AR typing, 1 and 0.97; phage typing, 0.29 and 0.89; PFGE, 0.99 and 0.95; AR-PFG typing, 1 and 0.95. The most frequently occurring AR-PFG types were 06-01, 07-02, 13-00, and 14-00 and were exhibited by 57, 7, 14, and 12% of isolates, respectively. During the study period, the distribution of AR-PFG type changed markedly, with the prevalence of one type (AR-PFG 06-01) increasing by 880%, from 22% (39/181) in 1999 to 80% (343/430) in 2003. Investigation of whether epidemiological types among blood culture isolates of MRSA were representative of the total MRSA population showed that there was no significant difference in most instances. MLST and SCCmec typing showed that AR-PFG types 06-01, 07-02, 13-00, and 14-00 were ST22-MRSA-IV, ST36-MRSA-II, ST8-MRSA-IID, and ST8-MRSA-IIE, respectively.

Baroreflex sensitivity measured by spectral and sequence analysis in cerebrovascular disease : methodological considerations

Baroreflex sensitivity (BRS) is impaired and of prognostic value in cerebrovascular disease. However, no studies to date have been published on the reproducibility of current methods of measuring BRS in this group. The reproducibility of sequence and spectral analysis methods were therefore assessed in subjects with cerebrovascular disease. A total of 14 subjects were assessed on 2 separate occasions at least 2 weeks apart, and beat-to-beat blood pressure (BP) and ECG trace were recorded for three 5-minute periods. These traces were then analyzed by spectral analysis using Fast Fourier Transform and sequence analysis. Reproducibility was calculated as the coefficient of variation (CV) and reproducibility coefficient (RC). There were no significant differences in heart rate, BP or BRS derived by either method between visits. Reproducibility was CV 22.2%, RC 6.04 ms/mmHg with spectral analysis, and CV 26.3%, RC 7.48 ms/mmHg for sequence analysis. There was close agreement between sequence and spectral derived BRS (r = 0.90). We have demonstrated that the use of spectral and sequence analysis to measure BRS is reproducible in subjects with cerebrovascular disease. These techniques are suitable for follow-up and intervention studies of BRS in this patient group.

Measuring red blood cell flow dynamics in a glass capillary using Doppler optical coherence tomography and Doppler amplitude optical coherence tomography

Blood, being a suspension of deformable red cells suspended in plasma, displays flow dynamics considerably more complicated than those of an ideal Newtonian fluid. Flow dynamics in blood capillaries of a few hundred micrometers in diameter are investigated using Doppler optical coherence tomography (DOCT) and Doppler amplitude optical coherence tomography (DAOCT), a novel extension of DOCT. Velocity profiles and concentration distributions of normal and rigidified in vitro red blood cell suspensions are shown to vary as functions of mean flow velocity, cell concentration, and cell rigidity. Deviation from the parabolic velocity profile expected for Pouseille flow is observed for both rigid and normal cells at low flow rates. Axial red cell migration both toward and away from the tube axis is observed for both rigid and normal cells as a function of flow velocity. Good agreement is found between our measurements, and theoretical expectations.

Development of weight and shape concerns in the aetiology of eating disorders

BACKGROUND

Although weight and shape concerns are considered to be integral to the psychopathology of anorexia and bulimia nervosa, uncertainties remain about developmental aspects of the aetiology of these concerns and their relationship to eating disorders.

AIMS

To review the recent literature on weight and shape concern, with particular emphasis on aetiology, to identify a possible developmental pathway from weight concern through abnormal eating behaviour to disorder.

METHOD

Literature review of Medline and Psychlit databases using the keywords 'eating disorder', 'weight concern', 'shape concern' and 'aetiology'. Inclusion criteria were based on the strength of quantitative research findings, originality of ideas and recent publication.

RESULTS

Weight and shape concerns follow a developmental pathway arising before the typical age for the development of eating disorders. The origins are multifactorial, with biological, family and sociocultural features predominating.

CONCLUSIONS

Although weight and shape concern seems commonly to underlie the development of eating disorders, an alternative pathway appears to exist through impulsivity and fear of loss of control. Prevention strategies may usefully focus on the attitudes and concerns that lead to dieting behaviour.

Caregiving arrangements of older disabled women, caregiving preferences, and views on adequacy of care

The role of women in caregiving to elderly people has focused primarily on their involvement as givers of care. In contrast, this article focuses on older women as recipients of caregiving. Data from the WHAS and the WHAS Caregiving Study are used to describe: the relationship of caregiving arrangements among moderately to severely disabled older women to sociodemographic, health and functional status; the characteristics of primary family caregivers and the assistance they provide; preferences for caregiving arrangements among both care recipients and caregivers; and views on adequacy of caregiving among older women cared for by family. Overall, about one quarter of these women had no caregiver, reflecting the inclusion in the WHAS of women with only moderate functional difficulty, but close to two-thirds relied on family members, and 15% on paid help only. Greater reliance on family was associated with being age 80 or older, black, and living with others. Women with poorer functioning--more ADL and IADL difficulties, difficulty taking medications without help, low cognitive functioning, not emotionally vital--also were significantly more likely to be cared for by family. Caregiving preferences varied among older women and their husband and daughter caregivers. Husbands consistently viewed in-home family help as the best caregiving arrangement regardless of levels of need. Older women and daughter caregivers both saw nursing homes as the best option for people with dementia and substantial care needs. One-quarter of elderly women chose in-home paid help as the best arrangement for meeting ADL/IADL needs. Older women generally held positive views of the assistance they received from family members. Younger women and lower income women were more likely to indicate they received less help than needed.

Impact of hospitalisation on the outcome of adolescent anorexia nervosa

BACKGROUND

Owing to the lack of controlled trials of treatment setting in adolescent anorexia nervosa, the benefits and costs of in-patient treatment are not established.

AIMS

To clarify the relationship between a range of presenting features, treatment received and medium- to long-term outcome in adolescent anorexia nervosa.

METHOD

A range of presenting variables were rated for 75 cases of DSM-III-R anorexia nervosa at presentation to an adolescent service, including the Morgan-Russell Global Assessment Score. Cases were followed up at 2-7 years and outcome rated according to reliable methods. Setting of treatment received was also recorded.

RESULTS

Two out of 75 cases had died by the time of follow-up. Adequate data for 72 enabled an outcome category to be assigned. The 21 who had received inpatient treatment had a significantly worse outcome than the 51 never admitted to hospital. Multivariate analysis suggests admission to be the major predictor of poor outcome.

CONCLUSIONS

The benefits and costs of admission to hospital require further investigation, ideally in a randomised-controlled trial. The negative consequences of in-patient treatment are neglected in research.

The stigma of eating disorders

Those who suffer from eating disorders often carry the added burden of stigmatizing attitudes from the lay public and the medical profession. These attitudes not only restrict the opportunities for effective treatment but also confer additional handicaps. To some extent, stigmatizing beliefs are based on partial truths about these disorders, namely their dangerousness, their sometimes poor response to treatment, the sufferers' part in their maintenance, and difficulties in communication. This review explores the truth of these beliefs and suggests ways in which a more positive approach to the management of eating disorders might help to reduce the stigma. This includes empathy with the patient's predicament and an approach to treatment in which the patient's wishes are paramount.