Behavioural susceptibility theory: the role of appetite in genetic susceptibility to obesity in early life

Excess weight gained during the early years and, in particular, rapid weight gain in the first 2 years of life, are a major risk factors for adult obesity. The growing consensus is that childhood obesity develops from a complex interaction between genetic susceptibility and exposure to an 'obesogenic' environment. Behavioural susceptibility theory (BST) was developed to explain the nature of this gene-environment interaction, and why the 'obesogenic' environment does not affect all children equally. It hypothesizes that inherited variation in appetite, which is present from birth, determines why some infants and children overeat, and others do not, in response to environmental opportunity. That is, those who inherit genetic variants promoting an avid appetite are vulnerable to overeating and developing obesity, while those who are genetically predisposed to have a smaller appetite and lower interest in food are protected from obesity-or even at risk of being underweight. We review the breadth of research to-date that has contributed to the evidence base for BST, focusing on early life, and discuss implications and future directions for research and theory. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part I)'.

Artificial Intelligence Literacy: Developing a Multi-institutional Infrastructure for AI Education

RATIONALE AND OBJECTIVES

To evaluate the effectiveness of an artificial intelligence (AI) in radiology literacy course on participants from nine radiology residency programs in the Southeast and Mid-Atlantic United States.

MATERIALS AND METHODS

A week-long AI in radiology course was developed and included participants from nine radiology residency programs in the Southeast and Mid-Atlantic United States. Ten 30 minutes lectures utilizing a remote learning format covered basic AI terms and methods, clinical applications of AI in radiology by four different subspecialties, and special topics lectures on the economics of AI, ethics of AI, algorithm bias, and medicolegal implications of AI in medicine. A proctored hands-on clinical AI session allowed participants to directly use an FDA cleared AI-assisted viewer and reporting system for advanced cancer. Pre- and post-course electronic surveys were distributed to assess participants' knowledge of AI terminology and applications and interest in AI education.

RESULTS

There were an average of 75 participants each day of the course (range: 50-120). Nearly all participants reported a lack of sufficient exposure to AI in their radiology training (96.7%, 90/93). Mean participant score on the pre-course AI knowledge evaluation was 8.3/15, with a statistically significant increase to 10.1/15 on the post-course evaluation (p= 0.04). A majority of participants reported an interest in continued AI in radiology education in the future (78.6%, 22/28).

CONCLUSION

A multi-institutional AI in radiology literacy course successfully improved AI education of participants, with the majority of participants reporting a continued interest in AI in radiology education in the future.

Omega-3 Supplementation for the Prevention of Cognitive Decline in Older Adults: Does It Depend on Homocysteine Levels?

BACKGROUND

Recent evidence point towards an interaction between omega-3 (n-3) polyunsaturated fatty acids (PUFA) and plasma homocysteine (Hcy).

OBJECTIVES

This study tested the hypothesis that effects of red blood cell n-3 PUFA are modified according to baseline plasma Hcy in the large Mulit-domain Alzheimer Prevention Trial (MAPT) throughout the 3-years of treatment with an additional 2 years of observational follow-up.

DESIGN

Experimental study.

PARTICIPANTS

From the 1680 participants that were randomized in the four groups of the MAPT study (two of which received n-3 PUFA, the other two without n-3 PUFA), 782 were selected because they had baseline data on both Hcy and n-3 PUFA.

MEASUREMENTS

Cognitive performance was measured with a broad set of cognitive tests including free and total recall of the cued selective reminding test, digit symbol substitution test, category naming test and Trail-making tests (TMT-A and B) and Clinical dementia rating scale.

RESULTS

We found a significant association between TMT-A and red blood cell n-3 PUFA levels in participants with Hcy values ≤16.8 µMol/L after adjustments at baseline (Estimate: -1.3, 95% CI: -2.3; -0.3, p=0.01). Additionally, participants with high Hcy values had a significant worsening after adjustments in TMT-B after a 5-year n-3 PUFA supplementation, compared to low levels of Hcy (Mean difference: 34.8, 95% CI: 7.8;61.7).

CONCLUSION

This study shows that Hcy levels could modify the association between red blood cell n-3 PUFA and executive function. People with high Hcy may benefit less from a n-3 PUFA supplementation to prevent cognitive decline.

Homocysteine - from disease biomarker to disease prevention

We have reviewed the literature and have identified more than 100 diseases or conditions that are associated with raised concentrations of plasma total homocysteine. The commonest associations are with cardiovascular diseases and diseases of the central nervous system, but a large number of developmental and age-related conditions are also associated. Few other disease biomarkers have so many associations. The clinical importance of these associations becomes especially relevant if lowering plasma total homocysteine by B vitamin treatment can prevent disease and so improve health. Five diseases can at least in part be prevented by lowering total homocysteine: neural tube defects, impaired childhood cognition, macular degeneration, primary stroke, and cognitive impairment in the elderly. We conclude from our review that total homocysteine values in adults of 10 μmol/L or below are probably safe, but that values of 11 μmol/L or above may justify intervention. Homocysteine is more than a disease biomarker: it is a guide for the prevention of disease.

Effectiveness of B Vitamins and Their Interactions with Aspirin in Improving Cognitive Functioning in Older People with Mild Cognitive Impairment: Pooled Post-Hoc Analyses of Two Randomized Trials

BACKGROUND AND OBJECTIVES

A randomized placebo-controlled trial found a significant negative interaction between aspirin and B vitamins in cognitive functioning in older people with mild cognitive impairment (MCI). To validate this finding, we pooled data of this trial with that of a similar B-vitamin trial (VITACOG) to examine the effectiveness of B vitamins and their interactions with aspirin in improving global cognitive functioning and slowing brain atrophy in older people with MCI.

DESIGN

Pooled post-hoc analyses of two randomized placebo-controlled trials.

PARTICIPANTS

In total, 545 older people with MCI were included in the study.

INTERVENTION

Placebo or B-vitamin supplements (vitamin B12, folic acid with or without vitamin B6) for 24 months.

MEASUREMENTS

The primary outcome was the Clinical Dementia Rating scale-global score (CDR-global). The secondary outcomes were CDR-sum of box score (CDR-SOB), memory Z-score, executive function Z-score, and whole brain atrophy rate.

RESULTS

71 (26.2%) and 83 (30.3%) subjects in the active and placebo group respectively were aspirin users. Overall, B vitamins reduced whole brain atrophy rate significantly (P = 0.003), but did not have significant effect on CDR-global, CDR-SOB, memory and executive function. Aspirin use had significant negative interaction effects on B vitamins in CDR-global and CDR-SOB (Beta = 0.993, P = 0.038, and Beta = 0.583, P = 0.009, respectively), but not in memory or executive function Z-scores. Among aspirin non-users, B-vitamin group subjects had more favourable changes in CDR-global and CDR-SOB (P = 0.019 and 0.057, respectively). B vitamins significantly slowed brain atrophy in aspirin non-users (P = 0.001), but not in aspirin users, though the interaction term was not significant (Beta = 0.192, P = 0.276).

CONCLUSION

In older people with MCI, B vitamins had significantly favourable effects on global cognitive functioning and whole brain atrophy rate in those who were not taking aspirin, but not in aspirin users.

Linking monitoring and data analysis to predictions and decisions for the range-wide eastern black rail status assessment

The US Fish and Wildlife Service (USFWS) has initiated a re-envisioned approach for providing decision makers with the best available science and synthesis of that information, called the Species Status Assessment (SSA), for endangered species decision making. The SSA report is a descriptive document that provides decision makers with an assessment of the current and predicted future status of a species. These analyses support all manner of decisions under the US Endangered Species Act, such as listing, reclassification, and recovery planning. Novel scientific analysis and predictive modeling in SSAs could be an important part of rooting conservation decisions in current data and cutting edge analytical and modeling techniques. Here, we describe a novel analysis of available data to assess the current condition of eastern black rail Laterallus jamaicensis jamaicensis across its range in a dynamic occupancy analysis. We used the results of the analysis to develop a site occupancy projection model where the model parameters (initial occupancy, site persistence, colonization) were linked to environmental covariates, such as land management and land cover change (sea-level rise, development, etc.). We used the projection model to predict future status under multiple sea-level rise and habitat management scenarios. Occupancy probability and site colonization were low in all analysis units, and site persistence was also low, suggesting low resiliency and redundancy currently. Extinction probability was high for all analysis units in all simulated scenarios except one with significant effort to preserve existing habitat, suggesting low future resiliency and redundancy. With the results of these data analyses and predictive models, the USFWS concluded that protections of the Endangered Species Act were warranted for this subspecies.

Carbon-Based Electrode Materials for Microsupercapacitors in Self-Powering Sensor Networks: Present and Future Development

There is an urgent need to fulfill future energy demands for micro and nanoelectronics. This work outlines a number of important design features for carbon-based microsupercapacitors, which enhance both their performance and integration potential and are critical for complimentary metal oxide semiconductor (CMOS) compatibility. Based on these design features, we present CMOS-compatible, graphene-based microsupercapacitors that can be integrated at the back end of the line of the integrated circuit fabrication. Electrode materials and their interfaces play a crucial role for the device characteristics. As such, different carbon-based materials are discussed and the importance of careful design of current collector/electrode interfaces is emphasized. Electrode adhesion is an important factor to improve device performance and uniformity. Additionally, doping of the electrodes can greatly improve the energy density of the devices. As microsupercapacitors are engineered for targeted applications, device scaling is critically important, and we present the first steps toward general scaling trends. Last, we outline a potential future integration scheme for a complete microsystem on a chip, containing sensors, logic, power generation, power management, and power storage. Such a system would be self-powering.

No benefit of ultrasound-guided transversus abdominis plane blocks over wound infiltration with local anaesthetic in elective laparoscopic colonic surgery: results of a double-blind randomized controlled trial

AIM

Advances in laparoscopic techniques combined with enhanced recovery pathways have led to faster recuperation and discharge after colorectal surgery. Peripheral nerve blockade using transversus abdominis plane (TAP) blocks reduce opioid requirements and provide better analgesia for laparoscopic colectomies than do inactive controls. This double-blind randomized study was performed to compare TAP blocks using bupivacaine with standardized wound infiltration with local anaesthetic (LA).

METHOD

Seventy-one patients were randomized to receive either TAP block or wound infiltration. The TAP blocks were performed by experienced anaesthetists who used ultrasound guidance to deliver 40 ml of 0.25% bupivacaine post-induction into the transverse abdominis plane. In the control group, 40 ml of 0.25% bupivacaine was injected around the trocar and the extraction site by the surgeon. Both groups received patient-controlled analgesia (PCA) with intravenous morphine. Patients and nursing staff assessed pain scores 6, 12, 24 and 48 h after surgery. The primary outcome was overall morphine use in the first 48 h.

RESULTS

Of the 71 patients, 20 underwent a right hemicolectomy and 51 a high anterior resection. The modified intention-to-treat analysis showed no significant differences in overall morphine use [47.3 (36.2-58.5) mg vs 46.7 (36.2-57.3) mg; mean (95% CI), P = 0.8663] in the first 48 h. Pain scores were similar at 6, 12, 24 and 48 h. No differences were found regarding time to mobilization, resumption of diet and length of hospital stay.

CONCLUSION

In elective laparoscopic colectomies, standardized wound infiltration with LA has the same analgesic effect as TAP blocks post-induction using bupivacaine at 48 h.

Publisher's Note: Hydrogen Bonds in Excited State Proton Transfer [Phys. Rev. Lett. 117, 163002 (2016)]

This corrects the article DOI: 10.1103/PhysRevLett.117.163002.

Hydrogen Bonds in Excited State Proton Transfer

Hydrogen bonding interactions between biological chromophores and their surrounding protein and solvent environment significantly affect the photochemical pathways of the chromophore and its biological function. A common first step in the dynamics of these systems is excited state proton transfer between the noncovalently bound molecules, which stabilizes the system against dissociation and principally alters relaxation pathways. Despite such fundamental importance, studying excited state proton transfer across a hydrogen bond has proven difficult, leaving uncertainties about the mechanism. Through time-resolved photoelectron imaging measurements, we demonstrate how the addition of a single hydrogen bond and the opening of an excited state proton transfer channel dramatically changes the outcome of a photochemical reaction, from rapid dissociation in the isolated chromophore to efficient stabilization and ground state recovery in the hydrogen bonded case, and uncover the mechanism of excited state proton transfer at a hydrogen bond, which follows sequential hydrogen and charge transfer processes.

Cognitive decline in the elderly after surgery and anaesthesia: results from the Oxford Project to Investigate Memory and Ageing (OPTIMA) cohort

Concerns have been raised about the effects on cognition of anaesthesia for surgery, especially in elderly people. We recorded cognitive decline in a cohort of 394 people (198 women) with median (IQR) age at recruitment of 72.6 (66.6–77.8) years, of whom 109 had moderate or major surgery during a median (IQR) follow‐up of 4.1 (2.0–7.6) years. Cognitive decline was more rapid in people who on recruitment were: older, p = 0.0003; male, p = 0.027; had worse cognition, p < 0.0001; or carried the ε4 allele of apoliprotein E (APOEε4), p = 0.008; and after an operation if cognitive impairment was already diagnosed, p = 0.0001. Cognitive decline appears to accelerate after surgery in elderly patients diagnosed with cognitive impairment, but not other elderly patients.

☛ CPD available at http://www.learnataagbi.org

Bilayer insulator tunnel barriers for graphene-based vertical hot-electron transistors

Vertical graphene-based device concepts that rely on quantum mechanical tunneling are intensely being discussed in the literature for applications in electronics and optoelectronics. In this work, the carrier transport mechanisms in semiconductor-insulator-graphene (SIG) capacitors are investigated with respect to their suitability as electron emitters in vertical graphene base transistors (GBTs). Several dielectric materials as tunnel barriers are compared, including dielectric double layers. Using bilayer dielectrics, we experimentally demonstrate significant improvements in the electron injection current by promoting Fowler-Nordheim tunneling (FNT) and step tunneling (ST) while suppressing defect mediated carrier transport. High injected tunneling current densities approaching 10(3) A cm(-2) (limited by series resistance), and excellent current-voltage nonlinearity and asymmetry are achieved using a 1 nm thick high quality dielectric, thulium silicate (TmSiO), as the first insulator layer, and titanium dioxide (TiO2) as a high electron affinity second layer insulator. We also confirm the feasibility and effectiveness of our approach in a full GBT structure which shows dramatic improvement in the collector on-state current density with respect to the previously reported GBTs. The device design and the fabrication scheme have been selected with future CMOS process compatibility in mind. This work proposes a bilayer tunnel barrier approach as a promising candidate to be used in high performance vertical graphene-based tunneling devices.

Note: Establishing α-particle radiation damage experiments using the Dalton Cumbrian Facility's 5 MV tandem pelletron

Evaluating the radiation stability of mineral phases is a vital research challenge when assessing the performance of the materials employed in a Geological Disposal Facility for radioactive waste. This report outlines the setup and methodology for efficiently allowing the determination of the dose dependence of damage to a mineral from a single ion irradiated sample. The technique has been deployed using the Dalton Cumbrian Facility's 5 MV tandem pelletron to irradiate a suite of minerals with a controlled α-particle ((4)He(2+)) beam. Such minerals are proxies for near-field clay based buffer material surrounding radioactive canisters, as well as the sorbent components of the host rock.

Swarm motility of Salmonella enterica serovar Typhimurium is inhibited by compounds from fruit peel extracts

Controlling spread of human pathogens on fresh produce is a top priority for public health reasons. Isolation of compounds from agricultural waste that would control spread of human pathogens was explored using Salmonella enterica serovar Typhimurium as a model organism. In the environment, micro-organisms migrate as a 'community' especially when they move on moist surfaces. This type of motility is characterized as swarming motility. We examined extracts from agricultural waste such as soya bean husk, peels of orange, pineapple, avocado and pomegranate for antiswarming activity. Avocado and pineapple peels showed moderate (~40%) inhibition of swarming motility while pomegranate peel extract had high antiswarming activity (~85% inhibition) and was examined in further detail. Although the pomegranate peel extract was acidic, swarm-inhibitory activity was not due to low pH and the peel extract did not inhibit growth of Salmonella. Among the key swarm motility regulatory genes, class II (fliF, fliA, fliT and fliZ) and class III (fliC and fliM) regulators were downregulated upon exposure to pomegranate peel extract. Pomegranate peels offer great potential as a bioactive repellent for pathogenic micro-organisms on moist surfaces.

SIGNIFICANCE AND IMPACT OF THE STUDY

Controlling the spread of food-borne pathogens in moist environments is an important microbial food safety issue. Isolation of compounds from agricultural waste (such as fruit peels) that would control spread of human pathogens was explored using Salmonella enterica serovar Typhimurium as a model organism. Pomegranate peels offer great potential as a bioactive repellent for pathogenic micro-organisms.

Adherence to abiraterone among the first 86 recipients after release in Saskatchewan

Metastatic castration-resistant prostate cancer is now commonly treated with abiraterone, an orally administered chronic medication. Although abiraterone has certain advantages over docetaxel-based therapy, patients are now responsible for ensuring optimal adherence to their medication. To our knowledge, adherence to abiraterone in a real-world setting has never been described. The objective of the present study was to measure adherence to abiraterone among the first patients to receive the drug in Saskatchewan. Electronic pharmacy claims were obtained from the Saskatchewan Cancer Agency after removal of patient names and identifiers. All patients with at least 1 dispensation for abiraterone between August 2011 and October 2013 were eligible. The primary endpoint was the percentage of patients achieving optimal adherence at 6 months, defined as a medication possession ratio (mpr) of 80% or better. During the study period, 141 patients received abiraterone, among whom 86 could be followed for at least 6 months. Optimal adherence was achieved in 82.6% of patients (71 of 86) at 6 months, with 79.1% achieving a mpr of at least 90%. Of patients with available follow-up to 1 year, 81.6% (31 of 38) maintained optimal adherence during the entire period.

Electromechanical piezoresistive sensing in suspended graphene membranes

Monolayer graphene exhibits exceptional electronic and mechanical properties, making it a very promising material for nanoelectromechanical devices. Here, we conclusively demonstrate the piezoresistive effect in graphene in a nanoelectromechanical membrane configuration that provides direct electrical readout of pressure to strain transduction. This makes it highly relevant for an important class of nanoelectromechanical system (NEMS) transducers. This demonstration is consistent with our simulations and previously reported gauge factors and simulation values. The membrane in our experiment acts as a strain gauge independent of crystallographic orientation and allows for aggressive size scalability. When compared with conventional pressure sensors, the sensors have orders of magnitude higher sensitivity per unit area.

The association of fasting plasma sulfur-containing compounds with BMI, serum lipids and apolipoproteins

BACKGROUND AND AIM

Sulfur amino acids are recognized as potent modulators of lipid metabolism. Plasma total cysteine (tCys) is associated with fat mass, obesity and serum LDL-cholesterol and apolipoprotein (Apo)-B in large population studies. It is not known how fasting plasma concentrations of cysteine precursors and products relate to these associations in humans, given that sulfur-containing compounds (SCC) influence rodent weight gain and serum lipids.

METHODS AND RESULTS

We investigated the cross-sectional associations of fasting plasma SCC (methionine, total homocysteine, cystathionine, tCys, taurine and total glutathione) with BMI and fasting serum lipids and apolipoproteins in 854 men and women with and without cardiovascular disease (CVD). In multiple linear regression analysis adjusted for age, gender, CVD and other SCC, neither methionine, taurine, nor total glutathione was associated with BMI. Plasma taurine was, however, inversely related to HDL-cholesterol (partial r = -0.12, p = 0.004) and its associated apoA1 (partial r = -0.18, p < 0.001). Plasma cystathionine correlated positively with triglycerides and BMI, while tCys positively correlated with total cholesterol, LDL-cholesterol (partial r = 0.20, p < 0.001) and its associated apoB. The associations of SCC with serum lipids were independent of BMI. tCys was also independently associated with BMI (partial r = 0.20, p < 0.001) after adjustment for other SCC, glucose, lipids and apolipoproteins.

CONCLUSIONS

Fasting tCys is associated with BMI independently of metabolically related SCC. Elevation of plasma SCC is generally associated with an unfavorable lipid profile. The negative relations of plasma taurine with HDL-C and apoA1 deserve further investigation.

scAAV-mediated gene transfer of interleukin-1-receptor antagonist to synovium and articular cartilage in large mammalian joints

With the long-term goal of developing a gene-based treatment for osteoarthritis (OA), we performed studies to evaluate the equine joint as a model for adeno-associated virus (AAV)-mediated gene transfer to large, weight-bearing human joints. A self-complementary AAV2 vector containing the coding regions for human interleukin-1-receptor antagonist (hIL-1Ra) or green fluorescent protein was packaged in AAV capsid serotypes 1, 2, 5, 8 and 9. Following infection of human and equine synovial fibroblasts in culture, we found that both were only receptive to transduction with AAV1, 2 and 5. For these serotypes, however, transgene expression from the equine cells was consistently at least 10-fold higher. Analyses of AAV surface receptor molecules and intracellular trafficking of vector genomes implicate enhanced viral uptake by the equine cells. Following delivery of 1 × 10(11) vector genomes of serotypes 2, 5 and 8 into the forelimb joints of the horse, all three enabled hIL-1Ra expression at biologically relevant levels and effectively transduced the same cell types, primarily synovial fibroblasts and, to a lesser degree, chondrocytes in articular cartilage. These results provide optimism that AAV vectors can be effectively adapted for gene delivery to large human joints affected by OA.

Subcellular fractionation of splenic nerve: ATP, chromogranin A and dopamine beta-hydroxylase in noradrenergic vesicles

The subcellular particles in axons of the splenic nerve have been studied by centifrugation techniques. By differential centifrugation, five different types of particle could be distinguished and partly separated: noradrenaline-containing particles (noradrenergic vesicles), large and small lysosomes, mitochondria, and microsomal particles. In density gradient centrifugation, only one type of noradrenergic vesicle could he demonstrated. The noradrenergic vesicles and the mitochondria contain ATP. Two proteins (chromogranin A and dopamine beta-hydroxylase) are present in the noradrenergic vesicles.

P3-08-03: Exercise Increases Soluble Vascular Endothelial Growth Factor Receptor-1 (sFlt-1) in the Circulation of Adult Women

Background: Physical inactivity increases the risk of several different cancers, including breast cancer. Soluble fms-like tyrosine kinase-1 (sFlt-1) is an extra-cellular Ig-like domain of the VEGF receptor-1 that is released into the extracellular space and circulation where it inhibits the activities of VEGF. Over-expression of sFlt-1 has been shown to inhibit ovarian tumor growth in gene therapy experiments. The present study tests the hypothesis that exercise can increase sFlt-1 in the circulation of adult women.

Material and Methods: 63 African American and Caucasian adult woman volunteers aged 18–44 were enrolled into a prospective exercise study. All the participants walked on a treadmill for 30 minutes at a moderate intensity (40-60% heart rate reserve), and oxygen consumption (VO2) was quantified by utilizing a metabolic cart. Blood samples were collected before and immediately after exercise. The exercise test was conducted between the first and seventh day of the participant's menstrual cycle. The plasma concentrations of sFlt-1, unbound VEGF, and endostatin were measured using ELISA kits from R and D Systems.

Results: Plasma levels of sFlt-1 were 67.8±3.7 pg/ml immediately after exercise (30 minutes), significantly higher than basal levels of 54.5±3.3 pg/ml before exercise (P&lt;0.01; n=63). The % increase in sFlt-1 levels before and after exercise in adult women was 54%. There was no significant difference in the % increase of sFlt-1 levels between African American and Caucasian groups (P=0.5334). There was no significant difference in plasma levels of endostatin before (92.4±4.4 ng/ml) and immediately after (93.8±4.4 ng/ml; P=0.8216) exercise. The basal plasma levels of unbound VEGF (21.5±4.3 pg/ml) ware similar to the plasma levels of VEGF (22.5±4.6 pg/ml; P=0.8652) immediately after exercise.

Discussion: We previously reported that plasma levels of sFlt-1 significantly increased 30 minutes after exercise in adult men, in which plasma levels of unbound-VEGF significantly decreased and plasma levels of endostatin significantly increased 2 hours after exercise. Until now, there has been no data on whether exercise increases plasma sFlt-1 levels in women. Our study is the first to show that exercise in adult women significantly increases plasma levels of sFlt-1. VEGF pathways have both autocrine and paracrine effects for promoting breast cancer progression. Previous studies have demonstrated that sFlt-1 inhibits the activities of VEGF and suppresses ovarian tumor growth in mice. Exercise-induced plasma levels of sFlt-1 could be an important clinical biomarker to explore the mechanisms of exercise training in reducing breast cancer progression. The sFtl-1 is produced in the microvascular and macrovascular endothelial cells that exist throughout the skeletal muscle tissues. It is therefore plausible that release of sFlt-1 from the skeletal muscles into the circulation might be due to exercise-dependent reductions in oxygen tension in the skeletal muscle. In future studies, we will determine whether sFlt-1 can be released directly from the exercised muscle.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-08-03.

Association study of MICA and MICB in Alzheimer's disease

Following the replication of the association of the human leucocyte antigen (HLA) allele, HLA-B*07, with Alzheimer's disease (AD) in the cohort of the Oxford Project to Investigate Memory and Ageing (OPTIMA) in a previous study, we examined whether that association could be due to linkage disequilibrium with MICA or MICB alleles. We found a possible association of MICA*00801 heterozygotes with AD in subjects positive for the epsilon 4 allele of apolipoprotein E. This finding was supported by Hardy-Weinberg analysis, by stratified association analysis and by interaction analysis, but did not survive correction for multiple testing. In any case, these results do not explain our previously reported association of HLA-B*07 with AD.

Olfactory impairment is more marked in patients with mild dementia with Lewy bodies than those with mild Alzheimer disease

BACKGROUND

Dementia patients with anosmia are more likely to have Lewy body pathology at postmortem, but clinicopathological studies have only assessed olfaction in moderate dementia or an average of 5 years before death. It is not known whether, in patients with mild dementia (MMSE score over 20), olfactory function is more impaired in Alzheimer disease (AD) than dementia with Lewy bodies (DLB).

METHODS

Patients with mild DLB (n = 21), mild AD (n = 27), mild cognitive impairment (MCI) (n = 21) and controls (n = 47) were assessed using a 16-item olfactory identification test and an olfactory threshold test which used sticks impregnated with differing concentrations of butanol.

RESULTS

Patients with mild DLB had impaired olfactory identification ability compared with those with mild AD or MCI, independent of age, cognitive function and sex. The sensitivity of a cutoff score of seven correct responses out of 16 was 0.81 for distinguishing mild DLB from mild AD (AUC 0.682). The specificity, positive predictive value and negative predictive value for the same cut-off score were 0.41, 0.48 and 0.73, respectively. The olfactory threshold was not different in the AD and DLB groups.

CONCLUSIONS

Simple bedside tests of olfactory identification merit further examination for their potential to improve the identification of patients with DLB when used alongside existing criteria. They are insufficiently specific for use in screening.

Plasma vitamin B12 status and cerebral white-matter lesions

BACKGROUND AND OBJECTIVE

Elevated homocysteine has been associated with a higher prevalence of cerebral white-matter lesions and infarcts, and worse cognitive performance. This raises the question whether factors involved in homocysteine metabolism, such as vitamin B(12), are also related to these outcomes. This study examined the association of several markers of vitamin B(12) status with cerebral white-matter lesions, infarcts and cognition.

METHODS

The study evaluated the association of plasma concentrations of vitamin B(12), methylmalonic acid, holotranscobalamin and transcobalamin saturation with cerebral white-matter lesions and infarcts at baseline and cognition at baseline and during follow-up among 1019 non-demented elderly participants of the population-based Rotterdam Scan Study. Analyses were adjusted for several potential confounders, including homocysteine and folate concentration.

RESULTS

Poorer vitamin B(12) status was significantly associated with greater severity of white-matter lesions, in particular periventricular white-matter lesions, in a concentration-related manner. Adjustment for common vascular risk factors (including blood pressure, smoking, diabetes and intima media thickness) did not alter the associations. Adjustment for homocysteine and folate modestly weakened the associations. No association was observed for any of the studied markers of vitamin B(12) status with presence of brain infarcts and baseline cognition or cognitive decline during follow-up.

CONCLUSIONS

These results indicate that vitamin B(12) status in the normal range is associated with severity of white-matter lesions, especially periventricular lesions. Given the absence of an association with cerebral infarcts, it is hypothesised that this association is explained by effects on myelin integrity in the brain rather than through vascular mechanisms.

Maternal separation exaggerates the toxic effects of 6-hydroxydopamine in rats: implications for neurodegenerative disorders

Many studies have shown that early life stress may lead to impaired brain development, and may be a risk factor for developing psychiatric pathologies such as depression. However, few studies have investigated the impact that early life stress might have on the onset and development of neurodegenerative disorders, such as Parkinson's disease, which is characterized in part by the degeneration of dopaminergic neurons in the nigrostriatal pathway. The present study subjected rat pups to a maternal separation paradigm that has been shown to model adverse early life events, and investigated the effects that it has on motor deficits induced by a unilateral, intrastriatal injection of 6-hydroxydopamine (12 microg/4 microl). The female rats were assessed for behavioral changes at 28 days post-lesion with a battery of tests that are sensitive to the degree of dopamine loss. The results showed that rats that had been subjected to maternal separation display significantly impaired performance in the vibrissae and single-limb akinesia test when compared to normally reared animals. In addition, there was a significant increase in the loss of tyrosine hydroxylase staining in maternally separated rats. Our results therefore suggest that adverse experiences sustained during early life contribute to making dopamine neurons more susceptible to subsequent insults occurring during more mature stages of life and may therefore play a role in the etiopathogenesis of Parkinson's disease.

Vitamin B12 status and rate of brain volume loss in community-dwelling elderly

OBJECTIVES

To investigate the relationship between markers of vitamin B(12) status and brain volume loss per year over a 5-year period in an elderly population.

METHODS

A prospective study of 107 community-dwelling volunteers aged 61 to 87 years without cognitive impairment at enrollment. Volunteers were assessed yearly by clinical examination, MRI scans, and cognitive tests. Blood was collected at baseline for measurement of plasma vitamin B(12), transcobalamin (TC), holotranscobalamin (holoTC), methylmalonic acid (MMA), total homocysteine (tHcy), and serum folate.

RESULTS

The decrease in brain volume was greater among those with lower vitamin B(12) and holoTC levels and higher plasma tHcy and MMA levels at baseline. Linear regression analysis showed that associations with vitamin B(12) and holoTC remained significant after adjustment for age, sex, creatinine, education, initial brain volume, cognitive test scores, systolic blood pressure, ApoE epsilon4 status, tHcy, and folate. Using the upper (for the vitamins) or lower tertile (for the metabolites) as reference in logistic regression analysis and adjusting for the above covariates, vitamin B(12) in the bottom tertile (<308 pmol/L) was associated with increased rate of brain volume loss (odds ratio 6.17, 95% CI 1.25-30.47). The association was similar for low levels of holoTC (<54 pmol/L) (odds ratio 5.99, 95% CI 1.21-29.81) and for low TC saturation. High levels of MMA or tHcy or low levels of folate were not associated with brain volume loss.

CONCLUSION

Low vitamin B(12) status should be further investigated as a modifiable cause of brain atrophy and of likely subsequent cognitive impairment in the elderly.

A SNP in the ACT gene associated with astrocytosis and rapid cognitive decline in AD

There is biochemical and animal model evidence supporting a pathological role of the ACT gene in AD. However, direct genetic evidence remains controversial and has been mostly limited to individual single nucleotide polymorphism (SNP) analysis. To resolve this apparent conflict we have used a high-density ACT SNP map, constructed haplotypes and explored correlations with phenotype. SNPs were identified by sequencing and used to construct haplotypes in 668 AD patients and 419 controls and a case-control association study was performed. Five SNPs, comprising five common haplotypes, represented 93% of ACT gene variation. Although no single SNP or haplotype was associated with AD status, a SNP in intron 2 was associated with later onset and more rapid cognitive decline (P=0.04). This SNP was both individually associated with severe astrocytosis (P=0.004) in AD patients and when combined with the signal sequence SNP (P=0.002). This suggests that astrocytosis may have a protective function for a limited period in some patients. These SNP associations either support a direct role for the ACT gene, in AD pathology or alternatively reflect linkage with polymorphisms in other genes nearby.

Screening for genital and anorectal sexually transmitted infections in HIV prevention trials in Africa

OBJECTIVES

To demonstrate the value of routine, basic sexually transmitted infection (STI) screening at enrolment into an HIV-1 vaccine feasibility cohort study and to highlight the importance of soliciting a history of receptive anal intercourse (RAI) in adults identified as "high risk".

METHODS

Routine STI screening was offered to adults at high risk of HIV-1 upon enrolment into a cohort study in preparation for HIV-1 vaccine trials. Risk behaviours and STI prevalence were summarised and the value of microscopy assessed. Associations between prevalent HIV-1 infection and RAI or prevalent STI were evaluated with multiple logistic regression.

RESULTS

Participants had a high burden of untreated STI. Symptom-directed management would have missed 67% of urethritis cases in men and 59% of cervicitis cases in women. RAI was reported by 36% of male and 18% of female participants. RAI was strongly associated with HIV-1 in men (adjusted odds ratio (aOR) 3.8; 95% CI 2.0 to 6.9) and independently associated with syphilis in women (aOR 12.9; 95% CI 3.4 to 48.7).

CONCLUSIONS

High-risk adults recruited for HIV-1 prevention trials carry a high STI burden. Symptom-directed treatment may miss many cases and simple laboratory-based screening can be done with little cost. Risk assessment should include questions about anal intercourse and whether condoms were used. STI screening, including specific assessment for anorectal disease, should be offered in African research settings recruiting participants at high risk of HIV-1 acquisition.

A radar study of emigratory flight and layer formation by insects at dawn over southern Britain

Radar observations have consistently shown that high-altitude migratory flight in insects generally occurs after mass take-off at dusk or after take-off over a more extended period during the day (in association with the growth of atmospheric convection). In this paper, we focus on a less-studied third category of emigration - the 'dawn take-off' - as recorded by insect-monitoring radars during the summer months in southern England. In particular, we describe occasions when dawn emigrants formed notable layer concentrations centred at altitudes ranging from ca. 240 m to 700 m above ground, very probably due to the insects responding to local temperature maxima in the atmosphere, such as the tops of inversions. After persisting for several hours through the early morning, the layers eventually merged into the insect activity building up later in the morning (from 06.00-08.00 h onwards) in conjunction with the development of daytime convection. The species forming the dawn layers have not been positively identified, but their masses lay predominantly in the 16-32 mg range, and they evidently formed a fauna quite distinct from that in flight during the previous night. The displacement and common orientation (mutual alignment) characteristics of the migrants are described.

Sea to land transfer of anthropogenic radionuclides to the North Wales coast, Part II: aerial modelling and radiological assessment

Modelling calculations have been performed to predict the radiological impact of the sea to land transfer pathway to members of the public in North Wales from 1952 to 2004. The radionuclides of interest were (99)Tc, (137)Cs, (239,240)Pu and (241)Am and the exposure routes considered were food consumption, external and inhalation. The consumption of locally grown terrestrial food in the early to mid 1980s was the most significant source of exposure to all of the groups considered, with (239,240)Pu being the radionuclide contributing most to the dose. A maximum dose of 1.46microSvy(-1) was calculated for adult members of the critical consumption group in 1985, with doses for 2004 reducing to 0.59microSvy(-1). Despite the conservative approach of the dose calculations, the dose rate values are very low, less than 0.15% of the annual limit of 1000microSvy(-1) for the UK public from controlled radiation sources (excluding medical).

Changes in international normalized ratio (INR) and model for endstage liver disease (MELD) based on selection of clinical laboratory

Priority for liver transplantation is based on the Model for Endstage Liver Disease (MELD) score, a mathematical function which includes international normalized ratio (INR). We present an analysis to determine the lab-to-lab variation in INR at 14 clinical laboratories across the United States. We performed a survey to identify representative clinical laboratories across the United States, where INR was measured in the determination of MELD score. Five 'standard' samples for INR were formulated and were sent to the 14 clinical laboratories to determine variation in INR and MELD score. Among the 14 clinical laboratories, the range in INR for the five samples was: sample 1 (1.2-2.0), sample 2 (1.4-2.5), sample 3 (1.7-3.4), sample 4 (1.9-3.7) and sample 5 (2.4-5.1). The range in calculated MELD score was: sample 1 (8-14), sample 2 (10-17), sample 3 (12-20), sample 4 (14-21) and sample 5 (16-25). The selection of the clinical laboratory used to determine INR may result in substantial changes in MELD score independent of severity-of-illness. These data suggest that further review of interlaboratory variation in MELD should be undertaken because of the potential impact on prioritization for liver transplantation.

A review of irradiated fuel particle releases from the Windscale Piles, 1950-1957

Radiological assessments have assumed that the mass of irradiated uranium oxide particles inadvertently released to the atmosphere from the Windscale Piles, two nuclear reactors at Windscale Works, Sellafield, England, during the 1950s was 20 kg. This paper re-examines the assumptions upon which this figure was based and concludes that the value is a realistically conservative estimate of the release, consistent with current radiological protection practice. The mass estimate is derived from a reanalysis of plant data produced at the time. The environmental data on which the initial estimates were based are reconfirmed, and additional support is provided by an interpretation of modelling studies of both the total deposition and milk concentrations resulting from that deposition. Milk-monitoring data from the time are shown to be consistent with the release assumptions used in the dispersion modelling exercise. Finally, the issue of statistical undersampling is addressed using the particle numbers and size distributions produced by the modelling exercise.

Appetitive flight patterns of male Agrotis segetum moths over landscape scales

An analysis is presented of the first harmonic radar studies of pheromone-plume locating flights of male Agrotis segetum moths over distances of up to 500 m. Upon release most moths flew in a direction having a downwind component. The first significant changes in flight orientations occur in the immediate vicinity of a pheromone source. Moths that were initially flying downwind change course and start flying crosswind whilst those that initially flew crosswind change course and start flying upwind. It is shown that such behaviour is consistent with the adoption of an effective plume-location strategy, and conditions are identified when downwind flights would be more advantageous than crosswind ones. Additionally, some of the complex flight patterns that can arise at later times are shown to be compatible with the adoption of an optimal biased scale-free (Lévy-flight) searching strategy. It is found that disruptive doses of sex pheromone can have a marked influence upon male moth flight patterns.

[Conservative treatment of upper urinary tract tumors]

The histological appearance and the clinical behaviour of upper urinary tract urothelial tumours are almost identical to those of the bladder. Superficial papillary tumours rarely progress and turn to invasive disease despite a high frequency of recurrence. Technical developments in the endourology field have allowed full endoscopic access to upper tract tumours. Endoscopic resection or ablation of the tumour can be undertaken safely and effectively through ureteroscopy or percutaneous nephroscopy with low risk of extra-renal tumour seeding. For superficial (Ta, T1), low grade (I, II) tumours, a conservative approach can be selected without compromising survival and prognosis. For muscle invasive > T2 or high grade (III) tumours, nephroureterectomy remains the treatment of choice. Intracavitary BCG used after percutaneous resection reduces the risk of recurrence of upper tract urothelial tumours regardless of the grade. Finally, the world literature and our personal experience have shown that the tumour grade and stage are the two independent factors that affect survival of patients with upper urinary tract tumours.

Iron genes, iron load and risk of Alzheimer's disease

BACKGROUND

Compound heterozygotes of the haemochromatosis gene (HFE) variants, H63D and C282Y, have raised transferrin saturation compared with that in the wild type. In the cohort of the Oxford Project To Investigate Memory and Ageing (OPTIMA), bicarriers of the HFE C282Y and the transferrin C2 gene variants are at five times greater risk of developing Alzheimer's disease; the addition of HFE H63D may raise the risk still further.

OBJECTIVE

To investigate transferrin saturation by HFE and transferrin genotype among people without dementia-that is, controls and those with mild cognitive impairment (MCI)-and also among those with Alzheimer's disease.

METHODS

Serum iron status and genotype were examined of 177 patients with Alzheimer's disease, 69 patients with MCI and 197 controls from the OPTIMA cohort.

RESULTS

Although each of these variants alone had relatively little effect on iron status, the combination of either HFE C282Y and HFE H63D or of HFE C282Y and transferrin C2 markedly raised transferrin saturation in those without dementia, but had little effect in those with mature Alzheimer's disease.

CONCLUSIONS

These combinations may raise the risk for Alzheimer's disease, owing to higher iron loads and therefore oxidative stress in the preclinical phase. If replicated, these findings will have implications for the prevention of Alzheimer's disease.

Exhaled nitric oxide measurements: clinical application and interpretation

The use of exhaled nitric oxide measurements (F(E)NO) in clinical practice is now coming of age. There are a number of theoretical and practical factors which have brought this about. Firstly, F(E)NO is a good surrogate marker for eosinophilic airway inflammation. High F(E)NO levels may be used to distinguish eosinophilic from non-eosinophilic pathologies. This information complements conventional pulmonary function testing in the assessment of patients with non-specific respiratory symptoms. Secondly, eosinophilic airway inflammation is steroid responsive. There are now sufficient data to justify the claim that F(E)NO measurements may be used successfully to identify and monitor steroid response as well as steroid requirements in the diagnosis and management of airways disease. F(E)NO measurements are also helpful in identifying patients who do/do not require ongoing treatment with inhaled steroids. Thirdly, portable nitric oxide analysers are now available, making routine testing a practical possibility. However, a number of issues still need to be resolved, including the diagnostic role of F(E)NO in preschool children and the use of reference values versus individual F(E)NO profiles in managing patients with difficult or severe asthma.

Apolipoprotein E epsilon4 and impaired episodic memory in community-dwelling elderly people: a marked sex difference. The Hordaland Health Study

BACKGROUND

Among elderly people without dementia, the apolipoprotein E epsilon4 allele (APOE4) has been associated with cognitive deficit, particularly in episodic memory, but few reports are available on whether this association differs by sex.

METHODS

In a community-dwelling Norwegian cohort of 2181 elderly people (55% women), aged 70-74 years, episodic memory was examined in relation to sex and APOE4 zygosity, with the Kendrick Object Learning Test (KOLT).

RESULTS

Possession of at least one APOE4 allele had a modest, detrimental effect on episodic memory in women, whereas in men, heterozygotes were unaffected and homozygotes had markedly lower scores across the distribution of KOLT scores. This sex difference was found consistently in all analyses: on comparing means and medians, examining trends across quintiles, and studying the distribution of scores and the risk of cognitive impairment. Results were broadly similar when adjusted for known determinants of cognition and also when severely impaired participants were excluded. The adjusted odds ratio (OR) of cognitive impairment in women was shown to be 1.8 (95% confidence interval (CI): 1.1 to 2.8) for heterozygotes and 1.1 (0.3 to 3.7) for homozygotes; the adjusted OR in men was observed to be 1.1 (0.6 to 2.1) for heterozygotes and 10.7 (4.7 to 24) for homozygotes.

CONCLUSIONS

Although the harmful effect of APOE4 on episodic memory was modest in women, the risk was found to occur in about 30%. APOE4 was observed to have a dramatic effect on episodic memory in men, but only in homozygotes, who comprised about 3% of men: the whole male homozygous group showed a marked shift to lower memory scores.

Effect of physical restraint on oxidative stress in mice fed a selenium and vitamin E deficient diet

Physical restraint has been associated with increased oxidative damage to lipid, protein, and DNA. The purpose of this experiment was to determine whether physical restraint would further exacerbate oxidative stress in mice fed a selenium (Se) and vitamin E (VE) deficient diet. Three-week- old mice were fed a Torula yeast diet containing adequate or deficient Se and VE. Menhaden oil was added to the deficient diet to impose an additional oxidative stress. After 4 wk feeding, half the mice in each group were restrained for 5 d in well-ventilated conical tubes for 8 h daily. Mice fed the Se and VE deficient diets had increased liver thiobarbituric acid-reactive substance (TBARS) levels and decreased liver glutathione peroxidase (GPX1) activity and alpha-tocopherol levels. Plasma corticosterone levels were elevated in restrained mice fed the deficient diet compared to unrestrained mice fed the adequate diet. Restraint had no effect on liver TBARS or alpha-tocopherol levels. Liver GPX1 activity, however, was lower in restrained mice fed the adequate diet. In addition, liver superoxide dismutase (SOD) activity was lower in the restrained mice fed the adequate or deficient diet. Thus, under our conditions, Se and VE deficient diet, but not restraint, increased lipid peroxidation in mice. Restraint, however, decreased antioxidant protection in mice due to decreased activities of GPX1 and SOD enzymes.

Around the clock surveillance: simple graphic disturbance in patients with hemispatial neglect carries implications for the clock drawing task

BACKGROUND

Drawing, and the clock drawing task in particular, is widely used as a diagnostic tool in the study of hemispatial neglect. It is generally assumed that the errors in graphic production, such as the misplacement of numbers, reflect a visuospatial deficit, and that drawing production itself (for example, producing the circle) is unimpaired.

OBJECTIVES

To test this assumption by examining whether the production of simple circles is affected by neglect.

METHODS

16 right hemisphere stroke patients copied circles of various sizes and their drawings were measured for size accuracy.

RESULTS

Patients with more severe neglect produced greater scaling errors, consistently drawing the circle smaller than the original. Errors were not in the horizontal axis alone--shrinkage occurred equally in both height and width axes.

CONCLUSIONS

Neglect can co-occur with constructional difficulties that serve to exacerbate the symptoms presented. This should be taken into account in the assessment of even apparently simple drawing tasks.