Stylized versus voxel phantoms: quantification of internal organ chord length distances

Dosimetric calculations, whether for radiation protection or nuclear medicine applications, are greatly influenced by the use of computational models of humans, called anthropomorphic phantoms. As anatomical models of phantoms have evolved and expanded, thus has the need for quantifying differences among each of these representations that yield variations in organ dose coefficients, whether from external radiation sources or internal emitters. This work represents an extension of previous efforts to quantify the differences in organ positioning within the body between a stylized and voxel phantom series. Where prior work focused on the organ depth distribution vis-à-vis the surface of the phantom models, the work described here quantifies the intra-organ and inter-organ distributions through calculation of the mean chord lengths. The revised Oak Ridge National Laboratory stylized phantom series and the University of Florida/National Cancer Institute voxel phantom series including a newborn, 1-, 5-, 10- and 15 year old, and adult phantoms were compared. Organ distances in the stylized phantoms were computed using a ray-tracing technique available through Monte Carlo radiation transport simulations in MCNP6. Organ distances in the voxel phantom were found using phantom matrix manipulation. Quantification of differences in organ chord lengths between the phantom series displayed that the organs of the stylized phantom series are typically situated farther away from one another than within the voxel phantom series. The impact of this work was to characterize the intra-organ and inter-organ distributions to explain the variations in updated internal dose coefficient quantities (i.e. specific absorbed fractions) while providing relevant data defining the spatial and volumetric organ distributions in the phantoms for use in subsequent internal dosimetric computations, with prospective relevance to patient-specific individualized dosimetry, as well as informing machine learning definition of organs using these reference models.

186 Young Scholar Presentation: Immunometabolism during periods of negative nutrient balance or heat stress is altered by dietary methyl donor supply in dairy cows

Our research examined the effects of enhancing methyl donor supply on immunometabolism during periods of negative nutrient balance (NNB) or heat stress (HS). The first experiment examined the effects of post-ruminal choline supply during NNB on production and pathways of 1-carbon metabolism. Ten primiparous rumen-cannulated cows (158±24 DIM) were used in a replicated 5×5 Latin square design with 4d treatment periods and 10d of recovery. Treatments were unrestricted intake with abomasal infusion of water, restricted intake (R; 60% of net energy for lactation requirements) with abomasal infusion of water or R plus abomasal infusion of 6.25, 12.5, or 25 g/d choline ion. Liver tissue was collected at the end of each treatment period. Enhancing choline supply increased milk yields, but decreased liver triacylglycerol. Activity of betaine homocysteine methyltransferase increased with choline, while methionine synthase tended to increase, and cystathionine β-synthase was decreased. These changes were associated with increased liver and plasma Met. Overall, enhanced supply of choline during NNB increases flux through the Met cycle to regenerate Met and reduce liver triacylglycerol. The second experiment examined the effects of rumen-protected Met (RPM) during HS on mTOR (mechanistic target of rapamycin)-related signaling proteins in the mammary gland. Thirty-two multiparous cows (184±59 DIM) were assigned to an environmental treatment, and a dietary treatment [TMR with RPM (0.105% DM) or without (CON)] in a crossover design. There were 2 periods with 2 phases per period. In phase 1 (9d), all cows were in thermoneutral conditions (TN) and fed ad libitum. During phase 2 (9d), group 1 (n=16) was exposed to HS using electric heat blankets while group 2 (n=16) remained in TN but were pair-fed to HS counterparts. After a washout period (21d), the study was repeated (period 2), with environmental treatments being inverted and dietary treatments remaining the same. Mammary tissue was collected at the end of phase 2. Abundance of phosphorylated mTOR was greater with RPM and tended to be greater with HS. Control cows had a greater decrease in milk protein (%) during phase 2 (difference from phase 1) compared with RPM cows, suggesting that RPM supplementation during HS may support greater milk protein synthesis via mTOR activation. The third experiment investigated the effects of RPM during HS on the response of mammary gland explants to lipopolysaccharide (LPS). Twenty-five mg of tissue obtained from cows in the second experiment was incubated with 0 or 3 μg/mL of LPS for 2h. Incubation with LPS increased abundance of genes associated with inflammation, while HS decreased genes associated with antioxidant responses. Expression of NFKB1was greater in LPS-treated explants from non-HS compared with HS cows. These data indicate that HS reduced immune and antioxidant responses while RPM did not attenuate the inflammatory response induced by LPS in vitro. Overall, data indicated a beneficial effect of choline during NNB and Met during HS on immunometabolism in dairy cows.

Group-randomized trial of tailored brief shared decision-making to improve asthma control in urban black adults

AIMS

To assess the intervention effects of BREATHE (BRief intervention to Evaluate Asthma THErapy), a novel brief shared decision-making intervention and evaluate feasibility and acceptability of intervention procedures.

DESIGN

Group-randomized longitudinal pilot study.

METHODS

In total, 80 adults with uncontrolled persistent asthma participated in a trial comparing BREATHE (N = 40) to a dose-matched attention control intervention (N = 40). BREATHE is a one-time shared decision-making intervention delivered by clinicians during routine office visits. Ten clinicians were randomized and trained on BREATHE or the control condition. Participants were followed monthly for 3 months post-intervention. Data were collected from December 2017 - May 2019 and included surveys, lung function tests, and interviews.

RESULTS

Participants were Black/multiracial (100%) mostly female (83%) adults (mean age 45). BREATHE clinicians delivered BREATHE to all 40 participants with fidelity based on expert review of audiorecordings. While the control group reported improvements in asthma control at 1-month and 3-month follow-up, only BREATHE participants had better asthma control at each timepoint (β = 0.77; standard error (SE)[0.17]; p ≤ 0.0001; β = 0.71; SE[0.16]; p ≤ 0.0001; β = 0.54; SE[0.15]; p = .0004), exceeding the minimally important difference. BREATHE participants also perceived greater shared decision-making occurred during the intervention visit (β = 7.39; SE[3.51]; p = .03) and fewer symptoms at follow-up (e.g., fewer nights woken, less shortness of breath and less severity of symptoms) than the controls. Both groups reported improved adherence and fewer erroneous medication beliefs.

CONCLUSION

BREATHE is a promising brief tailored intervention that can be integrated into office visits using clinicians as interventionists. Thus, BREATHE offers a pragmatic approach to improving asthma outcomes and shared decision-making in a health disparity population.

IMPACT

The study addressed the important problem of uncontrolled asthma in a high-risk vulnerable population. Compared with the dose-matched attention control condition, participants receiving the novel brief tailored shared decision-making intervention had significant improvements in asthma outcomes and greater perceived engagement in shared decision-making. Brief interventions integrated into office visits and delivered by clinicians may offer a pragmatic approach to narrowing health disparity gaps. Future studies where other team members (e.g., office nurses, social workers) are trained in shared decision-making may address important implementation science challenges as it relates to adoption, maintenance, and dissemination. TRAIL REGISTRATION: clinicaltrials.gov # NCT03300752.

P373 Left atrial mechanics and aortic stiffness following high intensity interval training: a randomised controlled study

Background

Physical inactivity is associated with an increased risk of cardiovascular disease. High intensity interval training (HIIT) has been shown to improve important health parameters, including aerobic capacity, arterial blood pressure, cardiac autonomic modulation and left ventricular mechanics. However, adaptations in left atrial (LA) mechanics and aortic stiffness remain unclear. Therefore, the aim of the present study was to assess any left atrial and aortic adaptations to HIIT.

Methods

Forty-one physically inactive males and females (aged 23 ± 2.7 years) volunteered for the study. Participants were randomised to either a 4-week HIIT intervention (n = 21) or 4-week control period (n = 20). The HIIT protocol consisted of 3 x 30-second maximal cycle ergometer sprints with a resistance of 7.5% body weight, interspersed with 2-minutes of active unloaded recovery. Speckle tracking imaging of the left atrium and M-Mode tracing of the aorta was performed pre and post HIIT and control period using commercially available software (EchoPac; GE Medical Systems). Analysis of covariance, with baseline measures as the covariate, was used to explore any differences in left atrial mechanics and aortic stiffness between the intervention and control groups. Stepwise linear regression analysis using LA stiffness as the dependent variable was conducted.

Results

Following 4-weeks of HIIT, there was significant improvement in LA mechanics, including LA reservoir (13.9 ± 13.4%, p = 0.033) and LA stiffness (-0.05 ± 0.04%-1, p = 0.032) compared to the control condition. In addition, improvements were observed in aortic distensibility (2.1 ± 2.7 cm2 × dyn×-1 × 103, p = 0.031) and aortic stiffness index (-2.6 ± 4.6, p = 0.041) compared to the control condition. In stepwise linear regression analysis, aortic distensibility change was significantly associated with LA stiffness change (p = 0.002), with an R2 of 0.613.

Conclusion

A short-term programme of HIIT was associated with a significant improvement in LA mechanics and aortic stiffness. These adaptations may have important health implications and contribute to the improved left ventricular diastolic and systolic mechanics, aerobic capacity and reduced arterial blood pressure previously documented following HIIT.

Shared decision-making in the BREATHE asthma intervention trial: A research protocol

AIM

To evaluate the preliminary effectiveness of the BRief Evaluation of Asthma THerapy intervention, a 7-min primary care provider-delivered shared decision-making protocol that uses motivational interviewing to address erroneous asthma disease and medication beliefs.

DESIGN

A multi-centre masked two-arm group-randomized clinical trial.

METHODS

This 2-year pilot study is funded (September 2016) by the National Institute of Nursing Research. Eight providers will be randomized to one of two arms: the active intervention (N = 4) or a dose-matched attention control (N = 4). Providers will deliver the intervention to which they were randomized to 10 Black adult patients with uncontrolled asthma (N = 80). Patients will be followed three months postintervention to test the preliminary intervention effects on asthma control (primary outcome) and on medication adherence, lung function, and asthma-related quality of life (secondary outcomes).

DISCUSSION

This study will evaluate the preliminary impact of a novel shared decision-making intervention delivered in a real world setting to address erroneous disease and medication beliefs as a means of improving asthma control in Black adults. Results will inform a future, large-scale randomized trial with sufficient power to test the intervention's effectiveness.

IMPACT

Shared decision-making is an evidence-based intervention with proven effectiveness when implemented in the context of labour- and time-intensive research protocols. Medication adherence is linked with the marked disparities evident in poor and minority adults with asthma. Addressing this requires a novel multifactorial approach as we have proposed. To ensure sustainability, shared decision-making interventions must be adapted to and integrated into real-world settings.

TRIAL REGISTRATION

Registered at clincialtrials.gov as NCT03036267 and NCT03300752.

Mode of delivery in pregnancies complicated by major fetal congenital heart disease: a retrospective cohort study

OBJECTIVE

To determine the mode of delivery in pregnancies complicated by complex fetal congenital heart disease (CHD).

STUDY DESIGN

Five-year retrospective cohort study at a tertiary fetal medicine center (2007 to 2011). Cases of complex fetal CHD (n=126) were compared with 45 069 non-anomalous singleton infants ⩾500 g to determine rates of emergency intrapartum cesarean section (CS), preterm delivery and induction of labor.

RESULT

Intrapartum CS is significantly higher in fetal CHD than non-anomalous controls (21% vs 13.5%, odds ratio (OR) 1.7, 95% confidence interval (CI): 1.0 to 2.7; P=0.035), predominantly related to CS for non-reassuring fetal status (OR 2.2, 95% CI: 1.1 to 4.1; P=0.022). Although fetal CHD did not increase emergency CS rates in nulliparous women, CS was significantly increased in multiparous pregnancies (OR 2.4, 95% CI: 1.8 to 4.6; P=0.014). Rates of preterm delivery (OR 3.4, 95% CI: 2.0 to 5.4; P<0.0001) and induction of labor (OR 1.9, 95% CI: 1.3 to 2.9; P=0.001) were higher in the CHD cases.

CONCLUSION

Emergency CS is increased in fetal CHD, attributed to a higher rate of CS for non-reassuring fetal status and seen mostly in multiparous women.

Higher capecitabine AUC in elderly patients with advanced colorectal cancer (SWOGS0030)

Background:

The aging process is accompanied by physiological changes including reduced glomerular filtration and hepatic function, as well as changes in gastric secretions. To investigate what effect would aging have on the disposition of capecitabine and its metabolites, the pharmacokinetics between patients ⩾70 years and <60 years were compared in SWOG0030.

Methods:

Twenty-nine unresectable colorectal cancer patients were stratified to either ⩾70 or <60 years of age, where the disposition of capecitabine and its metabolites were compared.

Results:

Notable increase in capecitabine area under the curve (AUC) was accompanied by reduction in capecitabine clearance in ⩾70 years patients (P<0.05). No difference in 5'-deoxy-5-fluorocytidine, 5'-deoxy-5-fluorouridine (DFUR), and 5-fluorouracil (5FU) AUCs between the two age groups, suggesting that carboxylesterase and cytidine deaminase (CDA) activity was similar between the two age groups. These results suggest that metabolic enzymes involved in converting capecitabine metabolites are not altered by age. An elevation in capecitabine Cmax and reduction in clearance was seen in females, where capecitabine AUC was 40.3% higher in women. Elevation of DFUR Cmax (45%) and AUC (46%) (P<0.05) was also noted, suggesting that CDA activity may be higher in females.

Conclusion:

Increases in capecitabine Cmax and AUC was observed in patients ⩾70 years when compared with younger patients who were >60 years.

Improved gross efficiency during long duration submaximal cycling following a short-term high carbohydrate diet

To assess the effect of dietary manipulation on gross efficiency (GE), 15 trained male cyclists completed 3×2 h tests at submaximal exercise intensity (60% Maximal Minute Power). Using a randomized, crossover design participants consumed an isoenergetic diet (~4 000 kcal.day-1) in the 3 days preceding each test, that was either high in carbohydrate (HighCHO, [70% of the total energy derived from carbohydrate, 20% fat, 10% protein]), low in carbohydrate (LowCHO, [70% fat, 20% carbohydrate, 10% protein]) or contained a moderate amount of carbohydrate (ModCHO, [45% carbohydrate, 45% fat, 10% protein]). GE along with blood lactate and glucose were assessed every 30 min, and heart rate was measured at 5 s intervals throughout. Mean GE was significantly greater following the HighCHO than the ModCHO diet (HighCHO=20.4%±0.1%, ModCHO=19.6±0.2%; P<0.001). Additionally, HighCHO GE was significantly greater after 25 min (P=0.015) and 85 min (P=0.021) than in the LowCHO condition. Heart rate responses in the HighCHO condition were significantly lower than during the LowCHO tests (P=0.005). Diet had no effect on blood glucose or lactate (P>0.05). This study suggests that before the measurement of gross efficiency, participants' diet should be controlled and monitored to ensure the validity of the results obtained.

Converging evidence for the processing costs associated with ambiguous quantifier comprehension

Traditional neuroanatomic models of language comprehension have emphasized a core language network situated in peri-Sylvian cortex. More recent evidence appears to extend the neuroanatomic network beyond peri-Sylvian cortex to encompass other aspects of sentence processing. In this study, we evaluate the neuroanatomic basis for processing the ambiguity in doubly-quantified sentences. For example, a sentence like "All the dogs jumped in a lake" can be interpreted with a collective interpretation (e.g., several dogs jumping into a single lake) or a distributive interpretation (e.g., several dogs each jumping into a different lake). In Experiment 1, we used BOLD fMRI to investigate neuroanatomic recruitment by young adults during the interpretation of ambiguous doubly-quantified sentences in a sentence-picture verification task. We observed that young adults exhibited a processing cost associated with interpreting ambiguous sentences and this was related to frontal and parietal cortex recruitment. In Experiment 2, we investigate ambiguous sentence processing with the identical materials in non-aphasic patients with behavioral variant frontotemporal dementia (bvFTD) who have frontal cortex disease and executive and decision-making limitations. bvFTD patients are insensitive to ambiguity associated with doubly-quantified sentences, and this is related to the magnitude of their frontal cortex disease. These studies provide converging evidence that cortical regions that extend beyond peri-Sylvian cortex help support the processing costs associated with the interpretation of ambiguous doubly-quantified sentences.

Performance measures in three rounds of the English bowel cancer screening pilot

OBJECTIVES

To compare performance measures across all three rounds of the English bowel cancer screening faecal occult blood test pilot and their relation to social deprivation and ethnicity.

METHODS

In each round in three primary care trusts, data for a restricted population of over 48,500 aged 60-69 years were analysed. Individual-based data included postcode linked to area-based data on the Index of Multiple Deprivation (IMD) 2004, and ethnicity. Outcomes were the rates of screening and colonoscopy uptake, positivity and detection of neoplasia (adenomas or bowel cancer) and bowel cancer, and the positive predictive values (PPVs) of a positive test for neoplasia and bowel cancer. Sensitivity was calculated by the proportional incidence method using data on interval cancers identified from cancer registrations.

RESULTS

The overall uptake rate was 61.8%, 57.0% and 58.7% in the first, second and third rounds, respectively. Although the PPV for cancer decreased over the course of the three rounds (10.9% in the 1st round, 6.5% in 3rd round), the PPV for all neoplasia remained relatively constant (42.6% in 1st round, 36.9% in 3rd round). Deprivation and non-white ethnic background (principally Indian subcontinent in the pilot region) were associated with low screening and colonoscopy uptake rates, and this changed little over the three screening rounds. Uptake was lower in men, although differences in uptake between men and women decreased over time. Non-participation in previous rounds was a strong predictor of low uptake.

CONCLUSIONS

Performance measures are commensurate with expectations in a screening programme reaching its third round of screening, but a substantial ongoing effort is needed, particularly to address the effects of deprivation and ethnicity in relation to uptake.

Moxifloxacin and pyrazinamide susceptibility testing in a complex case of multidrug-resistant tuberculosis

Multidrug-resistant tuberculosis (MDR-TB) is a public health problem of global concern. It is critical that drug susceptibility testing (DST) methods accurately predict clinical response. We present a patient with a challenging case of MDR-TB with additional resistance to quinolones and pyrazinamide. Treatment with a regimen including high-dosage moxifloxacin, based on additional genotypic and phenotypic DST, produced excellent results. This case highlights the possibility of treatment with high-dose fluoroquinolones despite apparent bacterial resistance to these agents. Improved DST methods are necessary for both agents. Development of genotypic approaches may offer a susceptibility profile rapidly, enabling early introduction of individualised treatments.

Reproducibility of limb power outputs and cardiopulmonary responses to exercise using a novel swimming training machine

The purpose of this study was to determine the reproducibility of limb power outputs and cardiopulmonary responses, to incremental whole-body exercise using a novel swimming training machine. 8 swimmers with a mean age of 23.7 ± 4.6 (yrs), stature 1.77 ± 0.13 (m) and body mass of 74.7 ± 2.8 (kg) gave informed consent and participated in repeat exercise testing on the machine. All subjects performed 2 incremental exercise tests to exhaustion using front crawl movements. From these tests peak oxygen consumption (VO(₂peak)), peak heart rate (HR(peak)), peak power output (W (peak)) and individual limb power outputs were determined. Results showed there were no significant differences between test 1 and 2 for any variable at exhaustion, and the CV% ranged from 2.8 to 3.4%. The pooled mean values were; VO(₂peak) 3.7 ± 0.65 L.min⁻¹, HR (peak) 178.7 ± 6.6 b.min⁻¹ and W (peak) 349.7 ± 16.5 W. The mean contributions to the total power output from the legs and arms were (37.3 ± 4.1% and 62.7 ± 5.1% respectively). These results show that it is possible to measure individual limb power outputs and cardiopulmonary parameters reproducibly during whole-body exercise using this training machine, at a range of exercise intensities.

Validity and reliability of the Ergomopro powermeter

The aim of this investigation was to assess the validity and reliability of the Ergomopro powermeter. Nine participants completed trials on a Monark ergometer fitted with Ergomopro and SRM powermeters simultaneously recording power output. Each participant completed multiple trials at power outputs ranging from 50 to 450 W. The work stages recorded were 60 s in duration and were repeated three times. Participants also completed a single trial on a cycle ergometer designed to assess bilateral contributions to work output (Lode Excaliber Sport PFM). The power output during the trials was significantly different between all three systems, (p < 0.01) 231.2 +/- 114.2 W, 233.0 +/- 112.4 W, 227.8 +/- 108.8 W for the Monark, SRM and Ergomopro system, respectively. When the bilateral contributions were factored into the analysis, there were no significant differences between the powermeters (p = 0.58). The reliability of the Ergomopro system (CV%) was 2.31 % (95 % CI 2.13 - 2.52 %) compared to 1.59 % (95 % CI 1.47 to 1.74 %) for the Monark, and 1.37 % (95 % CI 1.26 - 1.50 %) for the SRM powermeter. These results indicate that the Ergomopro system has acceptable accuracy under these conditions. However, based on the reliability data, the increased variability of the Ergomopro system and bilateral balance issues have to be considered when using this device.

The UK colorectal cancer screening pilot: results of the second round of screening in England

An evaluation of the second round of faecal occult blood (FOB) screening in the English site of the UK Colorectal Cancer Screening Pilot (comprising the Bowel Cancer Screening Pilot based in Rugby, general practices in four Primary Care Trusts, and their associated hospitals) was carried out. A total of 127 746 men and women aged 50–69 and registered in participating general practices were invited to participate. In all, 15.9% were new invitees not included in the previous round. A total of 52.1% of invitees returned a screening kit. Uptake varied with gender, age, and level of deprivation; was lower than in the first round (51.9 vs 58.5% P<0.0001), but was high (81.1%) in those who had participated in the first round with a negative result. Test positivity was 1.77%, significantly higher than in the first round, and the detection rate of neoplasia similar (5.67 per 1000), resulting in a lower positive predictive value. The sensitivity of FOBt in the first round was estimated as 57.7–64.4%. There was a significant impact on workload, particularly on endoscopy services. The cancer detection rate (0.94 per 1000) was lower than in the first round. Effort will be required to minimise inequalities in uptake, and to ensure adequate capacity of endoscopy services.

Screening for patent ductus arteriosus

The aim of our study was to look at the amount of training required to accurately assess ductal patency in very low birth weight infants and to show that this service could be provided by non-cardiologists. Training consisted of an introductory echocardiography course, a CD package, and a total of 3 hours of teaching with a paediatric cardiologist. All of this was accomplished within the 3 months preceding our study. All newborn infants less than 1500 grams or less than 30 weeks gestation had an echocardiogram performed in the first 48 hours of life. A prediction was then made based on the echocardiogram findings as to whether the arterial duct would become a clinically significant one. We based our prediction on established echocardiography criteria for the prediction of ductal patency, namely a ductal diameter of greater than 1.5 millimetres, a left atrial-to-aortic ratio of greater than 1.4, and an abnormal pattern of flow in the distal aorta. In total, 20 very low birth weight infants were screened from March 2005 to June 2005. Fifteen infants did not develop any signs of an arterial duct and this was predicted correctly in 13 cases. Of the 5 infants who developed a clinically apparent duct 4 were predicted correctly, giving us a sensitivity and specificity of 80% and 87%. Our study shows that it is possible to predict ductal patency without extensive echocardiography training. It also shows us that a neonatology based screening programme for pre-symptomatic arterial ducts in very low birth weight infants would be feasible.

Impact of a national external quality assessment scheme for breast pathology in the UK

BACKGROUND

This article presents the results and observed effects of the UK National Health Service Breast Screening Programme (NHSBSP) external quality assurance scheme in breast histopathology.

AIMS/METHODS

The major objectives were to monitor and improve the consistency of diagnoses made by pathologists and the quality of prognostic information in pathology reports. The scheme is based on a twice yearly circulation of 12 cases to over 600 registered participants. The level of agreement was generally measured using kappa statistics.

RESULTS

Four main situations were encountered with respect to diagnostic consistency, namely: (1) where consistency is naturally very high-this included diagnosing in situ and invasive carcinomas (and certain distinctive subtypes) and uncomplicated benign lesions; (2) where the level of consistency was low but could be improved by making guidelines more detailed and explicit-this included histological grading; (3) where consistency could be improved but only by changing the system of classification-this included classification of ductal carcinoma in situ; and (4) where no improvement in consistency could be achieved-this included diagnosing atypical hyperplasia and reporting vascular invasion. Size measurements were more consistent for invasive than in situ carcinomas. Even in cases where there is a high level of agreement on tumour size, a few widely outlying measurements were encountered, for which no explanation is readily forthcoming.

CONCLUSIONS

These results broadly confirm the robustness of the systems of breast disease diagnosis and classification adopted by the NHSBSP, and also identify areas where improvement or new approaches are required.

The NHS breast screening programme (pathology) EQA: experience in recent years relating to issues involved in individual performance appraisal

BACKGROUND

The original role of the National Health Service breast screening programme (pathology) external quality assessment (EQA) scheme was educational; it aimed to raise standards, reinforce use of common terminology, and assess the consistency of pathology reporting of breast disease in the UK.

AIMS/METHODS

To examine the performance (scores) of pathologists participating in the scheme in recent years. The scheme has evolved to help identify poor performers, reliant upon setting an acceptable cutpoint. Therefore, the effects of different cutpoint strategies were evaluated and implications discussed.

RESULTS/CONCLUSIONS

Pathologists who joined the scheme improved over time, particularly those who did less well initially. There was no obvious association between performance and the number of breast cancer cases reported each year. This is not unexpected because the EQA does not measure expertise, but was established to demonstrate a common level of performance (conformity to consensus) for routine cases, rather than the ability to diagnose unusual/difficult cases. A new method of establishing cutpoints using interquartile ranges is proposed. The findings also suggest that EQA can alter a pathologist's practice: those who leave the scheme (for whatever reason) have, on average, marginally lower scores. Consequently, with the cutpoint methodology currently used (which is common to several EQA schemes) there is the potential for the cutpoint to drift upwards. In future, individuals previously deemed competent could subsequently be erroneously labelled as poor performers. Due consideration should be given to this issue with future development of schemes.

Aortic valvar atresia, interrupted aortic arch, and quadricuspid pulmonary valve: a rare combination

Aortic atresia and interrupted aortic arch is a rare cardiac combination. Review of the literature revealed nine cases. We present two patients with this combination and the additional finding of quadricuspid pulmonary valves, one of which was severely stenotic. In the latter patient, an aortopulmonary window was present. The other had a unique blood supply to the brachiocephalic arteries and ascending aorta from systemic collateral arteries. To the best of our knowledge, the association of a quadricuspid pulmonary valve with this combination has not been previously reported.

The role of the male flower spike as a cue for selective grazing in bladder saltbush

This paper reports the results of three cafeteria trials used to study palatability variation between the sex phenotypes of bladder saltbush (Atriplex vesicaria Heward ex Benth.). The results of the first trial show that Merino sheep preferentially grazed female samples compared to male ones, which supported earlier paddock-scale grazing trials and observations. In the second trial, the removal of male flower spikes led to increased consumption of male samples, suggesting that male flower spikes contain a grazing deterrent. The third trial showed that sheep were able to detect male material with or without spikes even when it was completely hidden within female plant material. In combination with observations made during the trials, these results suggest that there is a grazing deterrent present in male plants and that sheep use the male flower spike primarily as a visual cue when making grazing decisions.

Evidence for palatability variation between the sex phenotypes of bladder saltbush from small-plot grazing trials

This paper reports the results of the first intensive grazing trials to study palatability variation between the sex phenotypes of bladder saltbush (Atriplex vesicaria Hew. ex Benth.). The results show that Merino sheep preferentially graze female shrubs over male and bisexual shrubs in South Australia, which supports earlier paddock-scale observations made in New South Wales. Male shrubs with higher densities of flower spikes were consumed less than those with lower densities. However, when male flowers were small and/or sparse, the removal of male flowers by clipping did not significantly increase the consumption of male shrubs. Female shrubs with very low or very high densities of fruit tended to be consumed significantly more than those with moderate fruit densities. Other physical aspects such as plant growth habit and foliage density did not have a consistent influence on grazing behaviour. Chemical differences between the sex phenotypes are implicated. The presence of palatability variation between the sex phenotypes suggests that there is potential to refine the existing use of bladder saltbush as an indicator species in southern Australia.

Cervical HPV infection and neoplasia in a large population-based prospective study: the Manchester cohort

Cytology and histology records and cervical samples for HPV assay were obtained from a prospective cohort of 49 655 women attending clinics for routine cervical cytology in or near Manchester between 1988 and 1993. The women were followed up for cytological abnormality and neoplasia through the cytology laboratory's records. HPV at entry was assayed in an age- and period-stratified random sample of 7278 women and in prevalent and incident CIN3 cases. The prevalence of newly diagnosed CIN3 increased with time since last normal smear, indicating that most cases persist for several years. CIN3 prevalence did not increase further for screening intervals exceeding 5 years, however, suggesting that CIN3 eventually regresses cytologically. CIN2 prevalence increased less steeply with screening interval, while the prevalence of lesser abnormality was almost independent of screening interval. The prevalence of oncogenic HPV at entry declined from 19% among women aged under 25 to less than 3% at age 40 or above. Oncogenic HPV infection was strongly predictive of subsequent CIN3 (OR 17.2, 95% CI 10.4–28.4), but only weakly related to CIN2 (OR 2.3, 95% CI 0.5–10.7) and lesser abnormality (OR 1.4, 95% CI 0.8–2.5). At current incidence rates, the lifetime risk of developing CIN3 will be 9% in this population. The cumulative risk of CIN3 diagnosis among cytologically normal women with oncogenic HPV detected at entry was 28% (CI 18–43%) after 14 years. Persistence of oncogenic HPV may be more sensitive and specific than cytology for early detection of CIN3 and invasive cancer.

Sensitivity and specificity of serology in determining recent acute Campylobacter infection

BACKGROUND

The measurement of serum antibodies to Campylobacter spp. has been used to investigate links between prior Campylobacter infections and the development of Guillain-Barre syndrome and its variants. Little is known of the serum antibody response to acute infections in the short- or long-term.

AIMS

The aims of the present study were to investigate the normal serum response to an acute Campylobacter infection and the sensitivity and specificity of anti-Campylobacter antibodies in determining recent Campylobacter infection.

METHODS

An enzyme-linked immunosorbent assay (ELISA) method was used to measure serum anti-Campylobacter immunoglobulin G (IgG), IgA and IgM antibodies. Controls consisted of 420 blood donors without recent gastroenteritis, 25 patients with other gastrointestinal infections, 24 patients with neurological conditions not affecting the peripheral nerves and 19 patients with autoimmune disorders. Three patient groups were assessed: 99 patients with acute Campylobacter infections, all of whom were tested 3 weeks post-infection; 69 of these patients tested 3-6 months later; and 74 additional patients tested >20 months post-infection. Western blot analysis was performed on controls and patients with high titre anti-Campylobacter antibodies to assess for cross-reactivity and specificity.

RESULTS

Following acute infections, all antibody classes rose in the majority of but not in all patients, followed by decreasing titres that did not return to baseline levels. Sixteen per cent of enteritis cases did not demonstrate a rise in titres and 9% of cases had significant levels of antibodies >20 months post-infection. The ELISA used was shown to be highly specific for the detection of Campylobacter antibodies.

CONCLUSION

The use of Campylobacter-specific antibody levels as the sole marker of prior infection is an unreliable method of determining the association between Campylobacter infection and neurological disease.

Consistency of staining and reporting of oestrogen receptor immunocytochemistry within the European Union—an inter-laboratory study

To assess the variability of oestrogen receptor (ER) testing using immunocytochemistry, centrally stained and unstained slides from breast cancers were circulated to the members of the European Working Group for Breast Screening Pathology, who were asked to report on both slides. The results showed that there was almost complete concordance among readers (kappa=0.95) in ER-negative tumours on the stained slide and excellent concordance among readers (kappa=0.82) on the slides stained in each individual laboratory. Tumours showing strong positivity were reasonably well assessed (kappa=0.57 and 0.4, respectively), but there was less concordance in tumours with moderate and low levels of ER, especially when these were heterogeneous in their staining. Because of the variation, the Working Group recommends that laboratories performing these stains should take part in a external quality assurance scheme for immunocytochemistry, should include a tumour with low ER levels as a weak positive control and should audit the percentage positive tumours in their laboratory against the accepted norms annually. The Quick score method of receptor assessment may also have too many categories for good concordance, and grouping of these into fewer categories may remove some of the variation among laboratories.

Control of molecular orientation in electrostatically stabilized ferroelectric liquid crystals

The continuously reorientable (XY-like) ferroelectric polarization density of a chiral smectic liquid crystal is shown experimentally to produce nearly complete screening of the applied electric field in an appropriate cell geometry. This screening, combined with the expulsion of polarization charge for large polarization materials, is shown to produce electrostatic control of the orientation of a uniform optic axis or polarization field.

High prevalence of non-albicans yeasts and detection of anti-fungal resistance in the oral flora of patients with advanced cancer

Oral fungal infections frequently develop in individuals with advanced cancer. This study examined the oral mycological flora of 207 patients receiving palliative care for advanced malignant disease. Demographic details and a clinical history were documented from each participant. A tongue swab was collected and cultured on CHROMAgar Candida (CHROMAgar Paris, France). All yeasts were identified by germ tube test, API ID 32C profiles and, for Candida dubliniensis, by species-specific PCR. Susceptibility to fluconazole and itraconazole was determined by a broth microdilution assay according to the National Committee for Clinical Laboratory Standards (NCCLS). At time of sampling, 54 (26%) of the 207 subjects had clinical evidence of a fungal infection and yeasts were isolated from 139 (67%) individuals. In total, 194 yeasts were isolated, of which 95 (49%) were Candida albicans. There was a high prevalence of Candidia glabrata (47 isolates) of which 34 (72%) were resistant to both fluconazole and itraconazole. All nine isolates of C. dubliniensis recovered were susceptible to both azoles. No relationship was established between anti-fungal usage in the preceding three months and the presence of azole resistant yeasts. This study of patients with advanced cancer has demonstrated a high incidence of oral colonization with non-C. albicans yeasts, many of which had reduced susceptibility to fluconazole and itraconazole. The role of improved oral care regimes and novel anti-fungal drugs merits further attention, to reduce the occurrence of fungal infection in these patients.

Liquid-crystal-solid interface structure at the antiferroelectric-ferroelectric phase transition

Total internal reflection is used to probe the molecular organization at the surface of a tilted chiral smectic liquid crystal at temperatures in the vicinity of the bulk antiferroelectric-ferroelectric phase transition. Data are interpreted using an exact analytical solution of a real model for ferroelectric order at the surface. In the mixture T3, ferroelectric surface order is expelled with the bulk ferroelectric-antiferroelectric transition. The conditions for ferroelectric order at the surface of an antiferroelectric bulk are presented.

Population growth: ecological success or development handicap?

"This paper considers whether biological criteria of reproductive success are useful in considering the causes and consequences of...human population growth. Particular attention is given to the relative rates of growth of different human groups. The paper considers mechanisms of human population regulation, their classification as 'demographic regimes', and the relative importance of 'positive' and 'preventive' checks. It concludes that while in general rapid population growth now usually confers disadvantages in terms of human welfare, more traditional interpretations may still be appropriate in view of, for example, the increasing political and social influence enjoyed by rapidly increasing minorities compared with other populations in the same society which have lower rates of reproduction."

A disability perspective from the United States on the case of Ms B

This article will examine the case of Ms B, a woman with tetraplegia for a year, who, prior to rehabilitation or return to community life, sought a ruling that doctors may turn off her ventilator. The authors are people with disabilities. Their analysis focuses on the manner in which the High Court (a) framed the case in terms of mental capacity, (b) addressed the issue of suicide and ambivalence, and (c) resolved informed consent and treatment alternative issues. While the disability community in the US does not oppose the general right to refuse treatment, there is significant concern about lack of informed consent and denial of desired treatment alternatives, and the cavalier manner in which these factors have been dismissed.