Common infections and neuroimaging markers of dementia in three UK cohort studies

INTRODUCTION

We aimed to investigate associations between common infections and neuroimaging markers of dementia risk (brain volume, hippocampal volume, white matter lesions) across three population-based studies.

METHODS

We tested associations between serology measures (pathogen serostatus, cumulative burden, continuous antibody responses) and outcomes using linear regression, including adjustments for total intracranial volume and scanner/clinic information (basic model), age, sex, ethnicity, education, socioeconomic position, alcohol, body mass index, and smoking (fully adjusted model). Interactions between serology measures and apolipoprotein E (APOE) genotype were tested. Findings were meta-analyzed across cohorts (Nmain  = 2632; NAPOE-interaction  = 1810).

RESULTS

Seropositivity to John Cunningham virus associated with smaller brain volumes in basic models (β = -3.89 mL [-5.81, -1.97], Padjusted  < 0.05); these were largely attenuated in fully adjusted models (β = -1.59 mL [-3.55, 0.36], P = 0.11). No other relationships were robust to multiple testing corrections and sensitivity analyses, but several suggestive associations were observed.

DISCUSSION

We did not find clear evidence for relationships between common infections and markers of dementia risk. Some suggestive findings warrant testing for replication.

Investigating associations between blood metabolites, later life brain imaging measures, and genetic risk for Alzheimer's disease

BACKGROUND

Identifying blood-based signatures of brain health and preclinical pathology may offer insights into early disease mechanisms and highlight avenues for intervention. Here, we systematically profiled associations between blood metabolites and whole-brain volume, hippocampal volume, and amyloid-β status among participants of Insight 46-the neuroscience sub-study of the National Survey of Health and Development (NSHD). We additionally explored whether key metabolites were associated with polygenic risk for Alzheimer's disease (AD).

METHODS

Following quality control, levels of 1019 metabolites-detected with liquid chromatography-mass spectrometry-were available for 1740 participants at age 60-64. Metabolite data were subsequently clustered into modules of co-expressed metabolites using weighted coexpression network analysis. Accompanying MRI and amyloid-PET imaging data were present for 437 participants (age 69-71). Regression analyses tested relationships between metabolite measures-modules and hub metabolites-and imaging outcomes. Hub metabolites were defined as metabolites that were highly connected within significant (p_FDR < 0.05) modules or were identified as a hub in a previous analysis on cognitive function in the same cohort. Regression models included adjustments for age, sex, APOE genotype, lipid medication use, childhood cognitive ability, and social factors. Finally, associations were tested between AD polygenic risk scores (PRS), including and excluding the APOE region, and metabolites and modules that significantly associated (p_FDR < 0.05) with an imaging outcome (N = 1638).

RESULTS

In the fully adjusted model, three lipid modules were associated with a brain volume measure (p_FDR < 0.05): one enriched in sphingolipids (hippocampal volume: ß = 0.14, 95% CI = [0.055,0.23]), one in several fatty acid pathways (whole-brain volume: ß =  - 0.072, 95%CI = [- 0.12, - 0.026]), and another in diacylglycerols and phosphatidylethanolamines (whole-brain volume: ß =  - 0.066, 95% CI = [- 0.11, - 0.020]). Twenty-two hub metabolites were associated (p_FDR < 0.05) with an imaging outcome (whole-brain volume: 22; hippocampal volume: 4). Some nominal associations were reported for amyloid-β, and with an AD PRS in our genetic analysis, but none survived multiple testing correction.

CONCLUSIONS

Our findings highlight key metabolites, with functions in membrane integrity and cell signalling, that associated with structural brain measures in later life. Future research should focus on replicating this work and interrogating causality.

The impact of lead poisoning from ammunition sources on raptor populations in Europe

Poisoning caused by ingestion of spent lead (Pb) ammunition in food items is a common cause of death of raptors. However, there has been no previous attempt to assess the impact of lead poisoning on populations of raptors throughout Europe or examine how this relates to the prevalence of hunting. We used measurements of lead concentration in the liver from over 3000 raptors of 22 species found dead or dying in the wild in 13 countries and a lead poisoning threshold of 20 ppm (dry weight) to assess the proportion of these in which lead poisoning caused or contributed to death. The prevalence of lead poisoning as a cause of death of raptors varied substantially among European countries and was positively correlated across countries with the reported number of hunters per unit area. Ten species had a non-zero proportion of individuals with concentrations exceeding the lead poisoning threshold ranging between 0.3% and 16.5%. The estimated annual conditional death rate from lead poisoning for these ten species averaged 0.44% (range 0.06-0.85%). Scavenging species feeding regularly on carcasses of game animals,tended to have a high annual probability of death from lead poisoning. So too did some predators which only sometimes scavenge, but prey on frequently hunted birds, such as gamebirds, waterfowl and pigeons, which may contain ingested or embedded lead shot. Small-bodied predators had a low annual probability of death from lead poisoning. Modelling indicated that European populations of adult raptors of the ten focal species averaged 6.0% smaller (range 0.2-14.4%) than they would be without the effects of lead poisoning. A given rate of lead poisoning mortality resulted in greater expected population reductions for species with high annual survival rate and late age at first breeding.

Early molecular oxidative stress biomarkers of ischemic penumbra in acute stroke

OBJECTIVES

To assess whether plasma biomarkers of oxidative stress predict diffusion-perfusion mismatch in patients with acute ischemic stroke (AIS).

METHODS

We measured plasma levels of oxidative stress biomarkers such as F2-isoprostanes (F2-isoPs), total and perchloric acid Oxygen Radical Absorbance Capacity (ORAC_TOT and ORAC_PCA), urinary levels of 8-oxo-7,8-dihydro-2'-deoxyguoanosine, and inflammatory and tissue-damage biomarkers (high-sensitivity C-reactive protein, matrix metalloproteinase-2 and -9) in a prospective study of patients with AIS presenting within 9 hours of symptom onset. Diffusion-weighted (DWI) and perfusion-weighted (PWI) MRI sequences were analyzed with a semiautomated volumetric method. Mismatch was defined as baseline mean transit time volume minus DWI volume. A percent mismatch cutoff of >20% was considered clinically significant. A stricter definition of mismatch was also used. Mismatch salvage was the region free of overlap by final infarction.

RESULTS

Mismatch >20% was present in 153 of 216 (70.8%) patients (mean [±SD] age 69.2 ± 14.3 years, 41.2% women). Patients with mismatch >20% were more likely to have higher baseline plasma levels of ORAC_PCA (p = 0.020) and F2-isoPs (p = 0.145). Multivariate binary logistic regression demonstrated that lnF2-isoP (odds ratio [OR] 2.44, 95% confidence interval [CI] 1.19-4.98, p = 0.014) and lnORAC_PCA (OR 4.18, 95% CI 1.41-12.41, p = 0.010) were independent predictors of >20% PWI-DWI mismatch and the stricter mismatch definition, respectively. lnORAC_TOT significantly predicted mismatch salvage volume (>20% mismatch p = 0.010, stricter mismatch definition p = 0.003).

CONCLUSIONS

Elevated hyperacute plasma levels of F2-isoP and ORAC are associated with radiographic evidence of mismatch and mismatch salvage in patients with AIS. If validated, these findings may add to our understanding of the role of oxidative stress in cerebral tissue fate during acute ischemia.

Reproductive den selection and its consequences for fisher neonates, a cavity-obligate mustelid

Selection of habitat characteristics by reproductive females during neonate development can mediate the influence of adverse environmental conditions on the fitness of offspring. Previous research has suggested that cavities and burrows used for reproduction by cavity-obligate species offer thermoregulatory benefits, access to prey, and can limit predation pressure. As fishers (Pekania pennanti) are secondary cavity-obligate breeders, we hypothesized that they select particular characteristics of reproductive den cavities at discrete stages of offspring development to mediate adverse biotic and environmental effects on their neonates. To test our hypothesis, we located 406 reproductive dens and 154 cavity rest sites used by 65 individual adult female fishers during 11 reproductive seasons (2005–2016) in northwestern California. We counted 53 (27 F, 26 M) kits in 31 litters born to 19 females during six of these reproductive seasons. The weight of kits varied significantly by sex and by age, whereas the length of kits varied only by age, suggesting that adult females in this population might be preferentially investing in male kits. We found that natal and early-maternal dens buffered minimum temperatures significantly more than late-maternal dens and cavities used during the nonreproductive season. A male fisher skull was also less likely to fit through the cavity openings of natal dens than through the openings of cavities used by adult females during the nonreproductive season. Litter survival was significantly lower at natal dens than at late-maternal dens. The age of adult female fishers did not affect the probability of litter survival. Our results emphasize the vulnerability of vertebrate offspring during early developmental periods and how cavity-obligate species select cavities to mediate environmental conditions during reproduction.

Oxidative Stress Biomarkers of Brain Damage: Hyperacute Plasma F2-Isoprostane Predicts Infarct Growth in Stroke

BACKGROUND AND PURPOSE

Oxidative stress is an early response to cerebral ischemia and is likely to play an important role in the pathogenesis of cerebral ischemic injury. We sought to evaluate whether hyperacute plasma concentrations of biomarkers of oxidative stress, inflammation, and tissue damage predict infarct growth (IG).

METHODS

We prospectively measured plasma F2-isoprostane (F2-isoP), urinary 8-oxo-7,8-dihydro-2'-deoxyguoanosine, plasma oxygen radical absorbance capacity assay, high sensitivity C reactive protein, and matrix metalloproteinase 2 and 9 in consecutive patients with acute ischemic stroke presenting within 9 hours of symptom onset. Patients with baseline diffusion-weighted magnetic resonance imaging and follow-up diffusion-weighted imaging or computed tomographic scan were included to evaluate the final infarct volume. Baseline diffusion-weighted imaging volume and final infarct volume were analyzed using semiautomated volumetric method. IG volume was defined as the difference between final infarct volume and baseline diffusion-weighted imaging volume.

RESULTS

A total of 220 acute ischemic stroke subjects were included in the final analysis. One hundred seventy of these had IG. Baseline F2-isoP significantly correlated with IG volume (Spearman ρ=0.20; P=0.005) and final infarct volume (Spearman ρ=0.19; P=0.009). In a multivariate binary logistic regression model, baseline F2-isoP emerged as an independent predictor of the occurrence of IG (odds ratio, 2.57; 95% confidence interval, 1.37-4.83; P=0.007). In a multivariate linear regression model, baseline F2-isoP was independently associated with IG volume (B, 0.38; 95% confidence interval, 0.04-0.72; P=0.03).

CONCLUSIONS

Elevated hyperacute plasma F2-isoP concentrations independently predict the occurrence of IG and IG volume in patients with acute ischemic stroke. If validated in future studies, measuring plasma F2-isoP might be helpful in the acute setting to stratify patients with acute ischemic stroke for relative severity of ischemic injury and expected progression.

The use of toxicokinetics and exposure studies to show that carprofen in cattle tissue could lead to secondary toxicity and death in wild vultures

Veterinary medicines can be extremely damaging to the environment, as seen with the catastrophic declines in Gyps vulture in South Asia due to their secondary exposure to diclofenac in their primary food source. Not surprisingly, concern has been raised over other similar drugs. In this study, we evaluate the toxicity of carprofen to the Gyps vulture clade through plasma pharmacokinetics evaluations in Bos taurus cattle (their food source) and Gyps africanus (a validated model species); tissue residues in cattle; and the effect of carprofen as a secondary toxicant as both tissue-bound residue or pure drug at levels expected in cattle tissues. Carprofen residues were highest in cattle kidney (7.72 ± 2.38 mg/kg) and injection site muscle (289.05 ± 98.96 mg/kg of dimension of 5 × 5 × 5 cm). Vultures exposed to carprofen as residues in the kidney tissue or pure drug equivalents showed no toxic signs. When exposed to average injection site concentrations (64 mg/kg) one of two birds died with evidence of severe renal and liver damage. Toxicokinetic analysis revealed a prolonged drug half-life of 37.75 h in the dead bird as opposed to 13.99 ± 5.61 h from healthy birds dosed intravenously at 5 mg/kg. While carprofen may generally be harmless to Gyps vultures, its high levels at the injection site in treated cattle can result in lethal exposure in foraging vultures, due to relative small area of tissue it is found therein. We thus suggest that carprofen not be used in domesticated ungulates in areas where carcasses are accessible or provided to vultures at supplementary feeding sites.

Survival of fishers in the southern Sierra Nevada region of California

Fishers in the western United States were recently proposed for listing under the U.S. Endangered Species Act because of concerns for loss of suitable habitat and evidence of a diversity of mortality risks that reduce survival. One of 2 remnant populations of fishers in California is in the southern Sierra Nevada region, where we studied them at 2 research sites in the Sierra National Forest. Our objectives were to evaluate whether survival was lower for male fishers and dispersal-aged individuals or if survival varied seasonally. We captured and monitored 232 radiocollared fishers from March 2007 to March 2014 and used model analyses to identify important predictors of survival. Fifty-two percent ( n = 120) of the radiocollared fishers died, and survival varied by sex and season, but not by age or between study sites. There was no evidence that dispersal-aged fishers experienced lower survival than older fishers. Annual survival trended lower for male (0.62 [95% CI 0.54–0.70]) compared to female fishers (0.72 [95% CI 0.67–0.78]), was lowest in the spring to mid-summer season (0.83 [95% CI 0.78–0.87]), and highest in late fall and winter (0.92 [95% CI 0.89–0.94]). Lower survival among male fishers appeared linked to males moving over large areas to locate mates, while lower survival for females was potentially related to high energetic cost of reproduction. It was possible but unknown if lower survival among all fishers in spring was linked to secondary exposure to toxicants dispersed around illicit marijuana grow sites. Six-month survival of juvenile fishers was 0.85 for females and 0.79 for males, but lower at 0.62 for females and 0.57 for males when adjusted for deaths before late September. Annual survival among adult female fishers was 20% lower than 0.90, a value that prior modeling suggested was required for population expansion in the overall southern Sierra Nevada. Survival data from our study imply a greater challenge for maintaining self-sustaining fisher populations in the southern Sierra Nevada region, and resource managers are working to mitigate several of the human-associated factors that limit population growth.

Frontotemporal correlates of impulsivity and machine learning in retired professional athletes with a history of multiple concussions

The frontotemporal cortical network is associated with behaviours such as impulsivity and aggression. The health of the uncinate fasciculus (UF) that connects the orbitofrontal cortex (OFC) with the anterior temporal lobe (ATL) may be a crucial determinant of behavioural regulation. Behavioural changes can emerge after repeated concussion and thus we used MRI to examine the UF and connected gray matter as it relates to impulsivity and aggression in retired professional football players who had sustained multiple concussions. Behaviourally, athletes had faster reaction times and an increased error rate on a go/no-go task, and increased aggression and mania compared to controls. MRI revealed that the athletes had (1) cortical thinning of the ATL, (2) negative correlations of OFC thickness with aggression and task errors, indicative of impulsivity, (3) negative correlations of UF axial diffusivity with error rates and aggression, and (4) elevated resting-state functional connectivity between the ATL and OFC. Using machine learning, we found that UF diffusion imaging differentiates athletes from healthy controls with significant classifiers based on UF mean and radial diffusivity showing 79–84 % sensitivity and specificity, and 0.8 areas under the ROC curves. The spatial pattern of classifier weights revealed hot spots at the orbitofrontal and temporal ends of the UF. These data implicate the UF system in the pathological outcomes of repeated concussion as they relate to impulsive behaviour. Furthermore, a support vector machine has potential utility in the general assessment and diagnosis of brain abnormalities following concussion.

Novel approaches to genetic analysis of fertility traits in New Zealand dairy cattle

The fertility of dairy cattle in New Zealand is well below industry targets, and the current New Zealand fertility breeding value (BV) could potentially be improved using additional information and traits. Data from 169 herds were analyzed to determine the benefits of using alternative phenotypic measures in the calculation of the fertility BV. The heritability of calving season day (CSD; calving season day as an integer day of the year) and the probability of an animal calving within 42 d of the planned start of calving (CR42) increased modestly (from 0.0206 to 0.0213 and 0.0087 to 0.0092, respectively) after accounting for the use of intravaginal progesterone-releasing devices for treatment of anestrous cows (anestrum treatment) and induced calvings. Incidence of either anestrum treatment or calving induction as a single binomial trait (AT/IND) had a heritability of 0.0223 and showed moderate genetic correlation with the probability of an animal being mated within 21 d of the planned start of mating (PM21; -0.4473), but much higher with CSD (0.8445). The use of pregnancy diagnosis data allowed fertility information that would otherwise be discarded to be included in analyses; when used to assign a prolonged CSD and a value of 0 for CR42 to animals that failed to calve, it increased the heritabilities of both of these traits (to 0.0278 and 0.0114, respectively). Because CSD was found to be more than twice as heritable as its binary counterpart, it shows potential to replace CR42 as the calving trait used in the fertility BV. Postpartum anestrous interval (PPAI), derived using incomplete premating estrous recording in some herds, had a heritability of 0.0813 and hence has potential as a trait to be included in genetic improvement programs but would require more rigorous recording of estrous during the premating period to be an effective trait. Based on selection index theory, the modifications made to current selection criteria using novel fertility traits increased the accuracy of prediction of fertility merit by more than 12%. Because of the increasing economic importance of fertility traits, and low heritabilities requiring large numbers of recorded daughters to get accurate fertility BV predictions on sires, data recorded on farm will become increasingly important in the genetic improvement of fertility.

First autonomous bio-optical profiling float in the Gulf of Mexico reveals dynamic biogeochemistry in deep waters

Profiling floats equipped with bio-optical sensors well complement ship-based and satellite ocean color measurements by providing highly-resolved time-series data on the vertical structure of biogeochemical processes in oceanic waters. This is the first study to employ an autonomous profiling (APEX) float in the Gulf of Mexico for measuring spatiotemporal variability in bio-optics and hydrography. During the 17-month deployment (July 2011 to December 2012), the float mission collected profiles of temperature, salinity, chlorophyll fluorescence, particulate backscattering (bbp), and colored dissolved organic matter (CDOM) fluorescence from the ocean surface to a depth of 1,500 m. Biogeochemical variability was characterized by distinct depth trends and local "hot spots", including impacts from mesoscale processes associated with each of the water masses sampled, from ambient deep waters over the Florida Plain, into the Loop Current, up the Florida Canyon, and eventually into the Florida Straits. A deep chlorophyll maximum (DCM) occurred between 30 and 120 m, with the DCM depth significantly related to the unique density layer ρ = 1023.6 (R2 = 0.62). Particulate backscattering, bbp, demonstrated multiple peaks throughout the water column, including from phytoplankton, deep scattering layers, and resuspension. The bio-optical relationship developed between bbp and chlorophyll (R2 = 0.49) was compared to a global relationship and could significantly improve regional ocean-color algorithms. Photooxidation and autochthonous production contributed to CDOM distributions in the upper water column, whereas in deep water, CDOM behaved as a semi-conservative tracer of water masses, demonstrating a tight relationship with density (R2 = 0.87). In the wake of the Deepwater Horizon oil spill, this research lends support to the use of autonomous drifting profilers as a powerful tool for consideration in the design of an expanded and integrated observing network for the Gulf of Mexico.

Abstract TP214: Hyperacute Plasma F2-Isoprostanes Predict Infarct Growth in Acute Ischemic Stroke

Objectives: Oxidative stress occurs as part of the earliest response to ischemia and is likely to play an important role in the pathogenesis of ischemic cerebral injury. We sought to evaluate whether hyperacute plasma concentrations of F2-isoprostane (F2-isoP), a biomarker of lipid peroxidation, predict infarct growth (IG), as a mediator of brain damage.

Methods: We prospectively measured plasma F2-isoP, high sensitivity-C reactive protein, matrix metalloproteinase-2 and -9, Oxygen Radical Absorbance Capacity assay, and urinary 8-hydroxydeoxyguanosine in acute ischemic stroke (AIS) patients presenting within 9 h of symptom onset. Patients with a baseline DWI MRI and a 48-h DWI or CT scan were included to evaluate the final infarct volume (FIV). Baseline DWIV and FIV were analyzed using semi-automated volumetric method. IG was defined as the difference between FIV and baseline DWIV.

Results: Of 489 AIS subjects, 220 [mean (SD) age 70.1 (15.1) y; 43.4% female; 40.5% treated with IV tPA] had both baseline DWI and follow-up imaging. Of these, 170 had IG of any size, and they were more likely to be male (p=0.032), to have prior transient ischemic attack (p=0.035) or diabetes mellitus (p=0.026), higher NIHSS score (p=0.001) and blood glucose levels (p=0.003) at admission, and higher median (IQR) baseline levels of F2-isoP [56.2 (36.4-75.3) vs. 42.0 (27.0-61.8) pg/mL, p=0.009]. Baseline F2-isoP and FIV (Spearman’s rho=0.19, p=0.009) as well as absolute IG volume (IGV) (Spearman’s rho=0.20, p=0.005) were significantly correlated. In a multivariable logistic regression model including all variables associated with IG at univariate p-value <0.05, as well as age and IV tPA, baseline F2-isoP emerged as an independent predictor of IG (OR 2.57, 95% CI 1.37-4.83; p=0.003). In linear regression model, baseline F2-isoP was independently associated with IGV (p=0.004). Inclusion of other biomarkers did not change the significance of F2-isoP in predicting IG (Bonferroni p <0.005).

Conclusions: Elevated hyperacute plasma F2-isoP concentrations independently predict IG and IGV in AIS patients. If validated in future studies, measuring plasma F2-isoP might be helpful in the acute setting to stratify AIS patients for progression and relative severity of ischemic injury.

Abstract TP223: Role of Plasma Biomarkers in Diagnosis of Ischemic Stroke Subtypes

Objectives: Identifying underlying stroke etiology plays critical role in acute management and secondary prevention strategies. Despite advanced diagnostics, up to 35% of ischemic strokes (IS) remain undetermined. We sought to evaluate the association between IS subtypes and plasma levels of biomarkers as representative of distinct etiologies underlying stroke subtypes.

Methods: We prospectively measured plasma high sensitivity-C reactive protein (hs-CRP), matrix metalloproteinase (MMP)-2 and MMP-9, F2-isoprostane (F2-isoP), Oxygen Radical Absorbance Capacity assay (ORAC), homocysteine and urinary 8-hydroxydeoxyguanosine (8OHdG), in patients presenting within 9 hours from acute ischemic stroke (AIS) onset. Stroke subtype was assigned by a stroke neurologist according to the Causative Classification of Stroke System (CCSS) criteria.

Results: There were 489 AIS subjects enrolled in this study [mean (SD) age 70.1 (15.1) y; 43.4% female; median (IQR) NIHSS 6 (3-13); 40.7% received IV tPA]. Among these AIS, 51% were of cardioembolic (CE), 17% of atherothrombotic, 7% of lacunar, 5% of other, and 20% of undetermined subtype. Patients with CE stroke were older and more likely to be female, non-smokers, have atrial fibrillation and congestive heart failure, but not carotid stenosis (all p<0.05). CE stroke subtype was also associated with greater stroke severity, and baseline levels of MMP-2 (p= 0.001) and ORAC (p= 0.008), as compared to other CCSS subtypes. In multivariate logistic regression analysis including all univariate predictors with p<0.05 as well as treatment with IV t-PA, baseline MMP-2 (OR 2.8, 95% CI 1.3-5.8; p= 0.006) and ORAC (OR 2.6, 95% CI 1.3-5.1; p= 0.007) was independently associated with CE stroke subtype. Conversely, the “other” stroke subtype was associated with lower levels of MMP-2 (OR 0.1, 95% CI 0.02-0.3; p= 0.001), and homocysteine levels were independently correlated with undetermined subtype (OR 2.2, 95% CI 1.2-4.1; p= 0.008).

Conclusions: In AIS patients, hyperacute plasma biomarkers are associated with specific stroke subtypes, reflective of the underlying pathophysiology. If validated in future studies, plasma biomarkers may play valuable role in early diagnosis and guide management of specific AIS subtypes.

Two new Eimeria species parasitic in corncrakes (Crex crex) (Gruiformes: Rallidae) in the United Kingdom

In this study we describe 2 new species of coccidia (Apicomplexa: Eimeriidae) parasites isolated from the feces of corncrake (Crex crex) (Gruiformes: Rallidae), bred in captivity in the U.K. Oocysts of Eimeria crecis n. sp. were approximately spherical and measured 15.3 μm (13-18) × 14.3 (12-16), providing an oocyst shape index of 1.1. A micropyle and oocyst residuum were absent, but a polar granule was present. Oocysts of Eimeria nenei n. sp. were ellipsoidal and measured 23.6 (21-26) × 18.1 (17-20), providing an oocyst shape index of 1.3. A micropyle and polar granule were present. Surveying free-living, wild adult corncrakes in Scotland (U.K.) demonstrated both parasite species to be widespread. These are the first species described to infect the corncrake, and they are distinct from those previously found to infect members of the closely related crane family (Gruiformes: Gruidae). Partial amplification and sequencing of the 18S rRNA gene and internal transcribed spacer 2 indicated a close relationship between the 2 proposed new species as a group distinct from the Eimeria species known to infect cranes. These newly identified parasite species have been associated with enteric disease in corncrakes being prepared for reproduction in captivity and reintroduction into England (U.K.).

Potential health risks to adults and children in the UK from exposure to dietary lead in gamebirds shot with lead ammunition

We estimate potential risks to human health in the UK from dietary exposure to lead from wild gamebirds killed by shooting. The main source of exposure to lead in Europe is now dietary. We used data on lead concentrations in UK gamebirds, from which gunshot had been removed following cooking to simulate human exposure to lead. We used UK food consumption and lead concentration data to evaluate the number of gamebird meals consumed weekly that would be expected, based upon published studies, to result in changes, over and above those resulting from exposure to lead in the base diet, in intelligence quotient (IQ), Systolic Blood Pressure and chronic kidney disease (CKD) considered in a recent opinion of the European Food Safety Authority (EFSA) to be significant at a population level and also in SAT test scores and in rates of spontaneous abortion. We found the consumption of <1 meal of game a week may be associated with a one point reduction in IQ in children and 1.2-6.5 gamebird meals per week may be associated with the other effects. These results should help to inform the development of appropriate responses to the risks from ingesting lead from ammunition in game in the UK and European Union (EU).

Targeted resequencing of a genomic region influencing tameness and aggression reveals multiple signals of positive selection

The identification of the causative genetic variants in quantitative trait loci (QTL) influencing phenotypic traits is challenging, especially in crosses between outbred strains. We have previously identified several QTL influencing tameness and aggression in a cross between two lines of wild-derived, outbred rats (Rattus norvegicus) selected for their behavior towards humans. Here, we use targeted sequence capture and massively parallel sequencing of all genes in the strongest QTL in the founder animals of the cross. We identify many novel sequence variants, several of which are potentially functionally relevant. The QTL contains several regions where either the tame or the aggressive founders contain no sequence variation, and two regions where alternative haplotypes are fixed between the founders. A re-analysis of the QTL signal showed that the causative site is likely to be fixed among the tame founder animals, but that several causative alleles may segregate among the aggressive founder animals. Using a formal test for the detection of positive selection, we find 10 putative positively selected regions, some of which are close to genes known to influence behavior. Together, these results show that the QTL is probably not caused by a single selected site, but may instead represent the joint effects of several sites that were targets of polygenic selection.

Global mapping of ecosystem services and conservation priorities

Global efforts to conserve biodiversity have the potential to deliver economic benefits to people (i.e., "ecosystem services"). However, regions for which conservation benefits both biodiversity and ecosystem services cannot be identified unless ecosystem services can be quantified and valued and their areas of production mapped. Here we review the theory, data, and analyses needed to produce such maps and find that data availability allows us to quantify imperfect global proxies for only four ecosystem services. Using this incomplete set as an illustration, we compare ecosystem service maps with the global distributions of conventional targets for biodiversity conservation. Our preliminary results show that regions selected to maximize biodiversity provide no more ecosystem services than regions chosen randomly. Furthermore, spatial concordance among different services, and between ecosystem services and established conservation priorities, varies widely. Despite this lack of general concordance, "win-win" areas-regions important for both ecosystem services and biodiversity-can be usefully identified, both among ecoregions and at finer scales within them. An ambitious interdisciplinary research effort is needed to move beyond these preliminary and illustrative analyses to fully assess synergies and trade-offs in conserving biodiversity and ecosystem services.

Movement of bromacil in a Hawaii soil under pineapple cultivation - a field study

Recent discovery of low concentrations of bromacil in drinking water prompted the State of Hawaii to examine the leaching behavior of bromacil in pineapple fields. This study is a follow up to earlier work on bromacil concentrations in soil profiles in a pineapple field in central Oahu, Hawaii. Soil samples were collected for bromacil analysis at different times prior to and after application from a pineapple field that was previously surveyed by other research workers. The leaching pattern of bromacil was further investigated at two different application rates (2.25 and 1.8 kg ha(-1)). The concentration of bromacil in the topsoil about 100 days after bromacil application (1.8 kg ha(-1)) was substantially higher in 2002 compared to 1999. The distribution profiles were generally consistent with the one presented in the previous study. Residual bromacil was present in the entire sampled zone (3m deep) about 18 months after the previous bromacil application. Over a period of 9 months, there was substantial dissipation of bromacil residue present in the topsoil. The residual concentration of bromacil in the area that received the reduced application rate (1.8 kg ha(-1)) were lower than those receiving the current application rate (2.25 kg ha(-1)) and the depth of penetration of the bromacil front was shallower at the reduced application rate. Because of the common practice of placing plastic mulch around the base of the pineapple plants to retain volatile nematicides, the applied bromacil was found to be concentrated in the areas between the plastic mulch, transported by runoff from the plastic. The study results encourage the use of less than the label led rate of application of bromacil for pineapple fields.

Identification and analysis of genomic regions with large between-population differentiation in humans

The primary aim of genetic association and linkage studies is to identify genetic variants that contribute to phenotypic variation within human populations. Since the overwhelming majority of human genetic variation is found within populations, these methods are expected to be effective and can likely be extrapolated from one human population to another. However, they may lack power in detecting the genetic variants that contribute to phenotypes that differ greatly between human populations. Phenotypes that show large differences between populations are expected to be associated with genomic regions exhibiting large allele frequency differences between populations. Thus, from genome-wide polymorphism data genomic regions with large allele frequency differences between populations can be identified, and evaluated as candidates for large between-population phenotypic differences. Here we use allele frequency data from approximately 1.5 million SNPs from three human populations, and present an algorithm that identifies genomic regions containing SNPs with extreme Fst. We demonstrate that our candidate regions have reduced heterozygosity in Europeans and Chinese relative to African-Americans, and are likely enriched with genes that have experienced positive natural selection. We identify genes that are likely responsible for phenotypes known to differ dramatically between human populations and present several candidates worthy of future investigation. Our list of high Fst genomic regions is a first step in identifying the genetic variants that contribute to large phenotypic differences between populations, many of which have likely experienced positive natural selection. Our approach based on between population differences can compliment traditional within population linkage and association studies to uncover novel genotype-phenotype relationships.

Diclofenac residues in carcasses of domestic ungulates available to vultures in India

Gyps vulture populations across the Indian subcontinent are declining rapidly and evidence indicates that veterinary use of the non-steroidal anti-inflammatory drug (NSAID) diclofenac is the major cause. Exposure of vultures to diclofenac is likely to arise from the consumption of livestock carcasses that have been treated shortly before death, however, detailed information regarding the prevalence and residual levels of diclofenac in carcasses available to vultures in India remains unreported. Here, we present data on diclofenac residues in 1848 liver samples taken from carcasses of dead livestock sampled at 67 sites in 12 states within India, between May 2004 and July 2005. Diclofenac residues were detected in carcasses in all states except Orisa, where only one site was sampled. The overall prevalence of detectable diclofenac (>10 microg kg(-1)) across all states was 10.1% and varied significantly among states, with up to 22.3% prevalence determined in Bihar. The geometric mean concentration of diclofenac found in samples in which the drug was detected was 352 microg kg(-1). The prevalence of carcasses containing diclofenac is similar to that previously proposed to be required to have caused the observed Gyps vulture declines in India. On the 11th of May 2006, the Drug Controller General (India) ordered the withdrawal of all licenses granted for the manufacture of diclofenac for veterinary use within India. However, if Gyps vultures are to be protected, potentially substantial existing stocks now need to be quickly and effectively removed from the Indian veterinary market.

Diclofenac disposition in Indian cow and goat with reference to Gyps vulture population declines

Gyps vultures across India are declining rapidly and the NSAID diclofenac has been shown to be the major cause. Vultures scavenge livestock carcasses that have been treated with diclofenac within the days preceding death. We present data on diclofenac disposition in Indian cow and goat, and field data on the prevalence of diclofenac in carcases in the environment. In the disposition experiment, animals were treated with a single intramuscular injection of diclofenac at 1000 microg kg-1 bw. In cow, diclofenac was detectable in liver, kidney and intestine up to 71 h post-treatment; in plasma, half-life was 12.2 h. In goat, tissue residues were undetectable after 26 h. Prevalence of diclofenac in liver from 36 dead livestock collected in the field was 13.9%. Data suggest that diclofenac residues in Indian cow and goat are short-lived, but diclofenac prevalence in carcasses available to vultures may still be very high.

Patterns of nucleotide misincorporations during enzymatic amplification and direct large-scale sequencing of ancient DNA

Whereas evolutionary inferences derived from present-day DNA sequences are by necessity indirect, ancient DNA sequences provide a direct view of past genetic variants. However, base lesions that accumulate in DNA over time may cause nucleotide misincorporations when ancient DNA sequences are replicated. By repeated amplifications of mitochondrial DNA sequences from a large number of ancient wolf remains, we show that C/G-to-T/A transitions are the predominant type of such misincorporations. Using a massively parallel sequencing method that allows large numbers of single DNA strands to be sequenced, we show that modifications of C, as well as to a lesser extent of G, residues cause such misincorporations. Experiments where oligonucleotides containing modified bases are used as templates in amplification reactions suggest that both of these types of misincorporations can be caused by deamination of the template bases. New DNA sequencing methods in conjunction with knowledge of misincorporation processes have now, in principle, opened the way for the determination of complete genomes from organisms that became extinct during and after the last glaciation.

The transcriptional landscape of the mammalian genome

This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.

Monitoring change in biodiversity through composite indices

The need to monitor trends in biodiversity raises many technical issues. What are the features of a good biodiversity index? How should trends in abundance of individual species be estimated? How should composite indices, possibly spanning very diverse taxa, be formed? At what spatial scale should composite indices be applied? How might change-points--points at which the underlying trend changes--be identified? We address some of the technical issues underlying composite indices, including survey design, weighting of the constituent indices, identification of change-points and estimation of spatially varying time trends. We suggest some criteria that biodiversity measures for use in monitoring surveys should satisfy, and we discuss the problems of implementing rigorous methods. We illustrate the properties of different composite indices using UK farmland bird data. We conclude that no single index can capture all aspects of biodiversity change, but that a modified Shannon index and the geometric mean of relative abundance have useful properties.

Flow cytometric determination of size and complex refractive index for marine particles: comparison with independent and bulk estimates

We advance a method to determine the diameter D and the complex refractive index (n + n'i) of marine particles from flow cytometric measurements of forward scattering, side scattering, and chlorophyll fluorescence combined with Mie theory. To understand better the application of Mie theory with its assumptions to flow cytometry (FCM) measurements of phytoplankton cells, we evaluate our flow cytometric-Mie (FCM-Mie) method by comparing results from a variety of phytoplankton cultures with independent estimates of cell D and with estimates of n and n' from the inversion of bulk measurements. Cell D initially estimated from the FCM-Mie method is lower than independent estimates, and n and n' are generally higher than bulk estimates. These differences reflect lower forward scattering and higher side scattering for single-cell measurements than predicted by Mie theory. The application of empirical scattering corrections improves FCM-Mie estimates of cell size, n, and n'; notably size is determined accurately for cells grown in both high- and low-light conditions, and n' is correlated with intracellular chlorophyll concentration. A comparison of results for phytoplankton and mineral particles suggests that differences in n between these particle types can be determined from FCM measurements. In application to natural mixtures of particles, eukaryotic pico/nanophytoplankton and Synechococcus have minimum mean values of n' in surface waters, and nonphytoplankton particles have higher values of n than phytoplankton at all depths.

Neuropsychologic impairment after coronary bypass surgery: effect of gaseous microemboli during perfusionist interventions

OBJECTIVE

Neuropsychologic impairment is a common complication of coronary bypass surgery. Cerebral microemboli during cardiopulmonary bypass are the principal cause of cognitive deficits after coronary bypass grafting. We have previously demonstrated that the majority of cerebral emboli occur during perfusionist interventions (ie, during the injection of air into the venous side of the cardiopulmonary bypass circuit). The purpose of this study was to determine whether an increase in perfusionist interventions is associated with an increased risk of postoperative cognitive impairment.

METHODS

Patients undergoing elective coronary artery bypass grafting (n = 83) underwent a battery of neuropsychologic tests preoperatively and 3 months postoperatively. Patients were divided into 2 groups according to the median value of perfusionist interventions during cardiopulmonary bypass. Group 1 patients (n = 42) had fewer than 10 perfusionist interventions, and group 2 patients (n = 41) had 10 or more interventions.

RESULTS

The 2 groups of patients were similar for all preoperative, intraoperative, and postoperative variables, with the exception of longer cardiopulmonary bypass times in group 2 patients (P <.001). Group 2 patients had lower mean scores on 9 of 10 neuropsychologic tests, with 3 (Rey Auditory Verbal Learning, Digit Span, and Visual Span) being statistically significant. Group 2 patients had worse cognitive test scores, even when controlling for increased bypass times. Group 2 patients had a nonsignificant trend toward an increased prevalence of neuropsychologic impairment 3 months postoperatively.

CONCLUSIONS

Introduction of air into the cardiopulmonary bypass circuit by perfusionists, resulting in cerebral microembolization, may contribute to postoperative cognitive impairment.

Methylation of the protein phosphatase 2A catalytic subunit is essential for association of Balpha regulatory subunit but not SG2NA, striatin, or polyomavirus middle tumor antigen

Binding of different regulatory subunits and methylation of the catalytic (C) subunit carboxy-terminal leucine 309 are two important mechanisms by which protein phosphatase 2A (PP2A) can be regulated. In this study, both genetic and biochemical approaches were used to investigate regulation of regulatory subunit binding by C subunit methylation. Monoclonal antibodies selectively recognizing unmethylated C subunit were used to quantitate the methylation status of wild-type and mutant C subunits. Analysis of 13 C subunit mutants showed that both carboxy-terminal and active site residues are important for maintaining methylation in vivo. Severe impairment of methylation invariably led to a dramatic decrease in Balpha subunit binding but not of striatin, SG2NA, or polyomavirus middle tumor antigen (MT) binding. In fact, most unmethylated C subunit mutants showed enhanced binding to striatin and SG2NA. Certain carboxy-terminal mutations decreased Balpha subunit binding without greatly affecting methylation, indicating that Balpha subunit binding is not required for a high steady-state level of C subunit methylation. Demethylation of PP2A in cell lysates with recombinant PP2A methylesterase greatly decreased the amount of C subunit that could be coimmunoprecipitated via the Balpha subunit but not the amount that could be coimmunoprecipitated with Aalpha subunit or MT. When C subunit methylation levels were greatly reduced in vivo, Balpha subunits were found complexed exclusively to methylated C subunits, whereas striatin and SG2NA in the same cells bound both methylated and unmethylated C subunits. Thus, C subunit methylation is critical for assembly of PP2A heterotrimers containing Balpha subunit but not for formation of heterotrimers containing MT, striatin, or SG2NA. These findings suggest that methylation may be able to selectively regulate the association of certain regulatory subunits with the A/C heterodimer.

Probing the mechanism of transport and compartmentalisation of polyamines in mammalian cells

BACKGROUND

Many mammalian cells possess an active polyamine uptake system but little is known about the molecular mechanism of this transporter. The fate of polyamines taken up from the medium and the relationship to polyamine homeostasis remains to be fully established. The aim of this study was to develop a range of modified polyamines, particularly ligands incorporating a fluorophore, to explore the structural tolerances of the polyamine transport system and to probe the intracellular location of polyamines acquired from the medium.

RESULTS

We synthesised a wide range of polyamine analogues incorporating cytotoxic agents, fluorescent chromophores and bulky substituents. All of these analogues have been shown to be good competitive inhibitors of spermidine uptake in a range of mammalian cells. Direct evidence for uptake of the fluorescent polyamine analogues and their subcellular distribution was obtained from confocal laser scanning fluorescence microscopy, which showed that they accumulated in granular structures within the cytoplasm and not in the nucleus. We demonstrated that their uptake is through the polyamine transport system by showing that pretreatment with DFMO, a potent inhibitor of polyamine biosynthesis, led to enhanced uptake, and cells deficient in the polyamine transport system did not accumulate these polyamine analogues.

CONCLUSIONS

The polyamine transport system has a surprisingly broad structural tolerance. Fluorophore-containing polyamine analogues derived from the extracellular pool are located in granular structures within the cytoplasm and not to any great extent in the nuclei of mammalian cells. These observations might be consistent with a mechanism involving receptor-mediated endocytosis, and the granular 'structures' seen might reflect polyamine compartmentalisation within vesicles.

The case of the amnesic intelligence officer

This paper describes a patient whose amnesia for an offence (fraud) and two fugue episodes occurred against the background of an underlying organic amnesia. The fugue states conformed in their duration and precipitating factors to previous accounts in the literature. The organic, anterograde memory impairment was attributed to multiple small infarcts and a larger infarction in the left medial temporal lobe, which were evident on MRI and PET scans after the patient had developed transient neurological signs. At follow-up, the anterograde amnesia had persisted, and the patient also showed some difficulty in retrieving autobiographical memories of past incidents or events, although other aspects of his retrograde memory were intact (including his knowledge of facts about his past life and his general knowledge of public events). The difficulty in retrieving autobiological incidents may have resulted from the presence of a moderate degree of frontal lobe dysfunction or, just possibly, from ischaemia in the left anterior temporal lobe. The persistence of the organic memory impairment and the importance of both the clinical history and neuropsychological testing in assessment are discussed, as well as the need to examine for possible organic factors in patients who may initially appear to manifest purely 'psychogenic' memory loss.

On the existence of independent explicit and implicit learning systems: an examination of some evidence

Hayes and Broadbent (1988), among others, have proposed that there are two independent systems of learning in humans. In their theory, they postulate that the explicit learning system gives rise to knowledge that is verbally describable, whereas the implicit learning system deals with knowledge that is not amenable to verbal report. Hayes and Broadbent presented data that they claimed supports a distinction between these two systems of learning. Their experiments involved the performance of subjects on two superficially similar tasks, and their claim was that one of the tasks induced learning in the explicit system, and the other induced learning in the implicit system. However, in five experiments here, we failed to find any convincing support for their empirical or theoretical claims. Our results suggest that the two tasks do not differ by inducing different types of learning, but simply differ in their degree of difficulty.

Driver fatalities and DUI offenders in New Jersey

Comparisons of driving and demographic characteristics were made on 407 driver fatalities (DFs) and 407 motorists convicted of driving under the influence (DUI). Significantly more DUI offenders (DOs) than DFs were men and had previous DUIs, accidents, license suspensions, and weekend "index" events. DFs with a blood or brain alcohol concentration (BAC) of 100 or above mg/dL matched most closely with DOs on negative driving events, "index" event days, and demographics. Conversely, DFs with negative BACs differed significantly with DOs on virtually all characteristics. High-BAC DFs and DOs may well be drawn from the same subpopulation of deviant drivers, whereas DFs with negative BACs seem similar to licensed drivers in general.

Passive smoking and middle ear effusions in children of British servicemen in West Germany--a point prevalence survey by clinics of outpatient attendance

Three hundred and twenty eight children of British servicemen serving in West Germany were studied in order to ascertain any relationship between parental smoking and the presence of middle ear effusion. The age range of the children was 18 months to 8 years. A questionnaire was completed by the parents of each child, and clinical examination and audiological tests demonstrated the presence or otherwise of middle ear effusions. One hundred and sixty four patients who had been referred with otological symptoms to the Ear, Nose and Throat Out Patient Department (ENT OPD) were surveyed, as were 164 other patients drawn from the Paediatric, Orthopaedic and Ophthalmic Out Patient Departments (OPDs) at BMH Rinteln. These 2 groups had similar age and sex distributions. The presence of middle ear effusions amongst children attending the ENT OPD was strongly associated with maternal cigarette smoking. This finding implies that mothers should not smoke at all in the same living accommodation as that used by their children. Paternal cigarette smoking showed no significant association with the presence of middle ear effusions.

ABO blood groups in hematologic malignancies

This article examines the genetic predisposition of individuals to lymphoma and leukemia with regard to the ABO blood groups. Blood samples from 558 patients suffering from various forms of lymphoma and leukemia were collected and typed for ABO blood groups. The ABO blood group phenotype frequencies of lymphoma patients were similar to those in control samples. Among leukemia patients, a significant increase in the frequency of the A2 phenotype was found in chronic lymphocytic leukemia. Possible mechanisms underlying the predisposition of individuals with the A2 blood group to chronic lymphocytic leukemia suggested by these preliminary results are discussed.

Management of traumatic rupture of the globe in aphakic patients

We report the successful treatment of three cases of traumatic ruptures of the globe complicated by massive choroidal hemorrhage, uveal prolapse and retinal detachment. All three of the eyes were aphakic prior to injury and all patients were age 64 or older. The presenting visual acuity in all patients was light perception. The blunt injury in each case caused a wound dehiscence at the site of previous cataract extraction. All injuries were associated with uveal prolapse. Secondary surgical intervention was performed when the hemorrhagic choroidal detachments had decreased as demonstrated by echography in the suprachoroidal space, occurring at an average of 14 days after injury. The management consisted of surgical drainage of the choroidal hemorrhage combined with vitrectomy and silicone oil injection. Successful reattachment of the retina was achieved in all cases. Postoperative epiretinal membranes formed in two cases but all were anatomically successful at six months. Final visual acuities varied from 20/70 to 1/200, visual acuity being a function of secondary contusive damage to the retina and choroid. We believe that in eyes sustaining severe blunt injuries resulting in rupture of the globe complicated by massive choroidal hemorrhage and retinal detachment, properly timed external drainage of the choroidal hemorrhage combined with pars plana vitrectomy and silicone oil injection is a useful approach.

Using optical correlation to measure leak rates in sealed packages

An optical correlation technique has been shown to accurately measure leak conduction rates from 10(-1) to 10(-6) atm cc/sec. Using hybrid microcircuit packages with glass capillary leakers, dimensional changes were detected as the packages were exposed to a small increase in external pressure. The rate at which the package returns to its original dimensions is measured and used, along with the internal free volume, to compute the leak rate. Because of its several advantages, the technique has the potential to become a useful nondestructive quality-control technique.

Multiparameter system for investigation of the effects of high-power ultrasound on metals

A multiparameter system has been developed which, for the first time, permits simultaneous measurement of sufficient quantities to test all of the proposed mechanisms for the influence of high-power ultrasound on metal specimens. Results of measurements using this system give new insight into the mechanical and thermal processes involved. Data are presented which show typical results obtained during tensile elongation of polycrystalline and single-crystal aluminum specimens.

Poly-HEMA sponge: a biocompatible calcification implant

Poly-hydroxyethyl methacrylate (Poly-HEMA) was investigated for biocompatibility and calcification potential. S.C. and I.M. implants and transplants to subperiosteal sites were examined. The material was judged to be tolerated by the host tissue since no inflammatory or degenerative changes were observed. This study established that calcification does occur. This calcification does not simulate bone formation; osteoblasts were not observed. The x-ray diffraction pattern resembles that of calcium hydroxyapatite.