Using Gene Transcription to Assess Ecological and Anthropological Stressors in Brown Bears

Increasingly, population- and ecosystem-level health assessments are performed using sophisticated molecular tools. Advances in molecular technology enable the identification of synergistic effects of multiple stressors on the individual physiology of different species. Brown bears (Ursus arctos) are an apex predator; thus, they are ideal candidates for detecting potentially ecosystem-level systemic perturbations using molecular-based tools. We used gene transcription to analyze 130 brown bear samples from three National Parks and Preserves in Alaska. Although the populations we studied are apparently stable in abundance and exist within protected and intact environments, differences in transcript profiles were noted. The most prevalent differences were among locations. The transcript patterns among groups reflect the influence of environmental factors, such as nutritional status, disease, and xenobiotic exposure. However, these profiles also likely represent baselines for each unique environment by which future measures can be made to identify early indication of population-level changes due to, for example, increasing Arctic temperatures. Some of those environmental changes are predicted to be potentially positive for brown bears, but other effects such as the manifestation of disease or indirect effects of oceanic acidification may produce negative impacts.

Coupling gene-based and classic veterinary diagnostics improves interpretation of health and immune function in the Agassiz's desert tortoise (Gopherus agassizii)

The analysis of blood constituents is a widely used tool to aid in monitoring of animal health and disease. However, classic blood diagnostics (i.e. hematologic and plasma biochemical values) often do not provide sufficient information to determine the state of an animal's health. Field studies on wild tortoises and other reptiles have had limited success in drawing significant inferences between blood diagnostics and physiological and immunological condition. However, recent research using gene transcription profiling in the threatened Mojave desert tortoise (Gopherus agassizii) has proved useful in identifying immune or physiologic responses and overall health. To improve our understanding of health and immune function in tortoises, we evaluated both standard blood diagnostic (body condition, hematologic, plasma biochemistry values, trace elements, plasma proteins, vitamin A levels) and gene transcription profiles in 21 adult tortoises (11 clinically abnormal; 10 clinically normal) from Clark County, NV, USA. Necropsy and histology evaluations from clinically abnormal tortoises revealed multiple physiological complications, with moderate to severe rhinitis or pneumonia being the primary cause of morbidity in all but one of the examined animals. Clinically abnormal tortoises had increased transcription for four genes (SOD, MyD88, CL and Lep), increased lymphocyte production, biochemical enzymes and organics, trace elements of copper, and decreased numbers of leukocytes. We found significant positive correlations between increased transcription for SOD and increased trace elements for copper, as well as genes MyD88 and Lep with increased inflammation and microbial insults. Improved methods for health assessments are an important element of monitoring tortoise population recovery and can support the development of more robust diagnostic measures for ill animals, or individuals directly impacted by disturbance.

A Global Perspective on the Population Structure and Reproductive System of Phyllosticta citricarpa

The citrus pathogen Phyllosticta citricarpa was first described 117 years ago in Australia; subsequently, from the summer rainfall citrus-growing regions in China, Africa, and South America; and, recently, the United States. Limited information is available on the pathogen's population structure, mode of reproduction, and introduction pathways, which were investigated by genotyping 383 isolates representing 12 populations from South Africa, the United States, Australia, China, and Brazil. Populations were genotyped using seven published and eight newly developed polymorphic simple-sequence repeat markers. The Chinese and Australian populations had the highest genetic diversities, whereas populations from Brazil, the United States, and South Africa exhibited characteristics of founder populations. The U.S. population was clonal. Based on principal coordinate and minimum spanning network analyses, the Chinese populations were distinct from the other populations. Population differentiation and clustering analyses revealed high connectivity and possibly linked introduction pathways between South Africa, Australia, and Brazil. With the exception of the clonal U.S. populations that only contained one mating type, all the other populations contained both mating types in a ratio that did not deviate significantly from 1:1. Although most populations exhibited sexual reproduction, linkage disequilibrium analyses indicated that asexual reproduction is important in the pathogen's life cycle.

Cessation of oil exposure in harlequin ducks after the Exxon Valdez oil spill: Cytochrome P4501A biomarker evidence

The authors quantified hepatic hydrocarbon-inducible cytochrome P4501A (CYP1A) expression, as ethoxyresorufin-O-deethylase (EROD) activity, in wintering harlequin ducks (Histrionicus histrionicus) captured in Prince William Sound, Alaska (USA), during 2011, 2013, and 2014 (22-25 yr following the 1989 Exxon Valdez oil spill). Average EROD activity was compared between birds from areas oiled by the spill and those from nearby unoiled areas. The present study replicated studies conducted from 1998 to 2009 demonstrating that harlequin ducks using areas oiled in 1989 had elevated EROD activity, indicative of oil exposure, up to 2 decades post spill. In the present study, it was found that average EROD activity during March 2011 was significantly higher in wintering harlequin ducks captured in oiled areas relative to unoiled areas, which the authors interpret to indicate that harlequin ducks continued to be exposed to residual Exxon Valdez oil up to 22 yr after the original spill. However, the 2011 results also indicated reductions in exposure relative to previous years. Average EROD activity in birds from oiled areas was approximately 2 times that in birds from unoiled areas in 2011, compared with observations from 2005 to 2009, in which EROD activity was 3 to 5 times higher in oiled areas. It was also found that average EROD activity during March 2013 and March 2014 was not elevated in wintering harlequin ducks from oiled areas. The authors interpret these findings to indicate that exposure of harlequin ducks to residual Exxon Valdez oil abated within 24 yr after the original spill. The present study finalizes a timeline of exposure, extending over 2 decades, for a bird species thought to be particularly vulnerable to oil contamination in marine environments. Environ Toxicol Chem 2017;36:1294-1300. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Cytoplasmic PML promotes TGF-β-associated epithelial-mesenchymal transition and invasion in prostate cancer

Epithelial-mesenchymal transition (EMT) is a key event that is involved in the invasion and dissemination of cancer cells. Although typically considered as having tumour-suppressive properties, transforming growth factor (TGF)-β signalling is altered during cancer and has been associated with the invasion of cancer cells and metastasis. In this study, we report a previously unknown role for the cytoplasmic promyelocytic leukaemia (cPML) tumour suppressor in TGF-β signalling-induced regulation of prostate cancer-associated EMT and invasion. We demonstrate that cPML promotes a mesenchymal phenotype and increases the invasiveness of prostate cancer cells. This event is associated with activation of TGF-β canonical signalling pathway through the induction of Sma and Mad related family 2 and 3 (SMAD2 and SMAD3) phosphorylation. Furthermore, the cytoplasmic localization of promyelocytic leukaemia (PML) is mediated by its nuclear export in a chromosomal maintenance 1 (CRM1)-dependent manner. This was clinically tested in prostate cancer tissue and shown that cytoplasmic PML and CRM1 co-expression correlates with reduced disease-specific survival. In summary, we provide evidence of dysfunctional TGF-β signalling occurring at an early stage in prostate cancer. We show that this disease pathway is mediated by cPML and CRM1 and results in a more aggressive cancer cell phenotype. We propose that the targeting of this pathway could be therapeutically exploited for clinical benefit.

Enhanced biological processes associated with alopecia in polar bears (Ursus maritimus)

Populations of wildlife species worldwide experience incidents of mass morbidity and mortality. Primary or secondary drivers of these events may escape classical detection methods for identifying microbial insults, toxin exposure, or additional stressors. In 2012, 28% of polar bears sampled in a study in the southern Beaufort Sea region of Alaska had varying degrees of alopecia that was concomitant with reduced body condition. Concurrently, elevated numbers of sick or dead ringed seals were detected in the southern Beaufort, Chukchi, and Bering seas in 2012, resulting in the declaration of an unusual mortality event (UME) by the National Oceanic and Atmospheric Administration (NOAA). The primary and possible ancillary causative stressors of these events are unknown, and related physiological changes within individual animals have been undetectable using classical diagnostic methods. Here we present an emerging technology as a potentially guiding investigative approach aimed at elucidating the circumstances responsible for the susceptibility of certain polar bears to observed conditions. Using transcriptomic analysis we identified enhanced biological processes including immune response, viral defense, and response to stress in polar bears with alopecia. Our results support an alternative mechanism of investigation into the causative agents that, when used proactively, could serve as an early indicator for populations and species at risk. We suggest that current or classical methods for investigation into events of unusual morbidity and mortality can be costly, sometimes unfocused, and often inconclusive. Advances in technology allow for implementation of a holistic system of surveillance and investigation that could provide early warning of health concerns in wildlife species important to humans.

Integrating Gene Transcription-Based Biomarkers to Understand Desert Tortoise and Ecosystem Health

Tortoises are susceptible to a wide variety of environmental stressors, and the influence of human disturbances on health and survival of tortoises is difficult to detect. As an addition to current diagnostic methods for desert tortoises, we have developed the first leukocyte gene transcription biomarker panel for the desert tortoise (Gopherus agassizii), enhancing the ability to identify specific environmental conditions potentially linked to declining animal health. Blood leukocyte transcript profiles have the potential to identify physiologically stressed animals in lieu of clinical signs. For desert tortoises, the gene transcript profile included a combination of immune or detoxification response genes with the potential to be modified by biological or physical injury and consequently provide information on the type and magnitude of stressors present in the animal's habitat. Blood from 64 wild adult tortoises at three sites in Clark County, NV, and San Bernardino, CA, and from 19 captive tortoises in Clark County, NV, was collected and evaluated for genes indicative of physiological status. Statistical analysis using a priori groupings indicated significant differences among groups for several genes, while multidimensional scaling and cluster analyses of transcription C T values indicated strong differentiation of a large cluster and multiple outlying individual tortoises or small clusters in multidimensional space. These analyses highlight the effectiveness of the gene panel at detecting environmental perturbations as well as providing guidance in determining the health of the desert tortoise.

Abstract P6-07-09: Identification of Trophinin associated protein (TROAP) as a novel biological marker in breast cancer (BC): Co-expression of TROAP and TOPO2A predicts response of anthracycline based chemotherapy (ATC-CT)

Introduction: Recently, TOPO2A alteration was found to be a predictor for ATC-CT and by using neural network and pathways analysis of gene expression array data, TROAP gene was revealed as a major hub in TOPO2A pathway and strongly related to genes that are involved in mitotic cell cycle regulation. In addition, we found that TROAP gene was among top 10 ranked genes out of 48,000 of transcripts, that accurately predicted worse clinical outcome, and differentiated between low and high grade based on a 10-fold external cross-validation analysis with an average classification accuracy of >99.999%. TROAP protein is essential for centrosome integrity and proper bipolar organisation of spindle assembly during mitosis and plays essential role in cell proliferation.

In the current study the molecular and clinicopathological functions of TROAP expression and its effect on management of breast cancer have been investigated.

Methods: The co-expression of TROAP and TOPO2A protein was evaluated by using dual immunoflurescent in BC cell lines. In addition both TROAP and TOP2A protein expressions were immunohistochemically (IHC) assessed in 40 normal breast tissues and a well characterised series of 1650 primary BC and were correlated to clinicopathological and other biomarkers. IHC staining was performed using Anti-TROAP rabbit polyclonal (HPA044102; Sigma).

The association between TROAP and response to chemotherapy was investigated in 350 ER negative BC treated with adjuvant ATC-CT and 260 locally advanced BC treated with neoadjuvant ATC-CT. In addition the clinical outcome of TROAP expression was evaluated in a series of 180 ER− high risk BC patients who did not received any CT.

Results: No expression of TROAP protein was observed in normal breast tissue while, 25% of BC showed TROAP protein overexpression. By using dual immunoflurescent in BC cell lines, The MCF7 cells showed strong cytoplasmic TROAP staining with no TOPO2A expression, while The T47D cells did not express TROAP but expressed TOPO2A. SKBr3, MDA468 and MDA231 cell lines showed co-expression of TROAP and TOPO2A. TROAP overexpression was significantly associated with aggressive clinico-pathological features including; high grade, high mitotic rate, absence of hormonal receptors, overexpression of HER2, TOP2A and EGFR (p < 0.001), Triple negative phenotype (p < 0.001), basal-like BC (p < 0.001), p53 mutation (p < 0.001) and inactive p16 (p < 0.001). With regard to outcome, receiving anthracycline chemotherapy had a positive impact on high risk ER− BC patients with TROAP protein over-expression as TROAP protein overexpression showed 50% less risk of recurrence compared to TROAP negative expression; p < 0.0001. Moreover, in locally advanced BC who received anthracycline-based neoadjuvant chemotherapy, 31/81 (39%) of BC with co-expression of TROAP+/TOPO2A+ achieved pCR while none of those with absence of both TROAP−/TOPO2A− (0/51) had achieved pCR (p < 0.00001).

Conclusion: TROAP is an important novel gene implicated in the survival of BC cells and its protein expression is a predictor for Anthracycline CT. TROAP may provide new avenues for the discovery of new predictive marker to guide therapeutic intervention.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-09.

Abstract P6-07-18: Identification of Sperm Associated Antigen 5 (SPAG5) as a novel biological and predictive biomarker in Breast cancer

Introduction: SPAG5 has been found to be involved in the functional and dynamic regulation of mitotic spindles, and to be essential for chromosome segregation fidelity. Recently we found by using neural network and pathways analysis of a gene expression array data that SPAG5 was among top 10 ranked genes out of 48,000 of transcripts, that accurately predicted worse clinical outcome based on a 10-fold external cross-validation analysis with an average classification accuracy of >99.999%. Moreover we found that 5% of BC showed amplification of SPAG5 locus at chromosome 17q11.2 and SPAG5 mRNA expression levels displayed a statistically significant correlation with its copy number.

Methods: In the current study the molecular and clinicopathological features of SPAG5 expression and its effect on management of BC have been investigated in 2800 BC patients with primary operable invasive BCs constituted four cohorts: 1) A series of 1650 BC patients received adjuvant endocrine and/or CMF chemotherapy according to NPI.2) A series of 256 BC received adjuvant anthracycline-based chemotherapy (ATC-CT)3) A series of 140 primary BC HER2+ patients treated with ATC-CT+ Herceptin 4) To validate SPAG5 as a predictor factor for ATC-CT, 260 patients with locally advanced primary breast cancer treated with neoadjuvant ATC-CT were included and the pathological complete response (pCR) was used to evaluate the response to chemotherapy.

Immunohistochemical staining was performed using Anti–SPAG5 rabbit polyclonal (HPA022479; Sigma).

Results: i) By using dual immunoflurescent in BC cell lines, co-expression of SPAG5 and proliferating cell nuclear antigen (PCNA) was detected in 4 out of 5 of the breast cancer cell lines screened (MCF7, T47D, MDA468 and MDA231) providing evidence for the importance of SPAG5 in cell proliferation. ii) 20% of breast cancer showed SPAG5 protein overexpression. SPAG5 overexpression showed a statistically significant association with ER−, PR−, triple negative phenotype, high grade tumour, high ki67, basal like phenotype and epithelial mesenchymal transition phenotype, p53 mutation and absence of DNA repair genes (BRCA1, ATM and XRCC1); p values <0.0001. iii) In high risk ER− BC patients who did not received any adjuvant therapy or received ineffective CMF chemotherapy, SPAG5+ protein expression had a similar risk of death and recurrence. Receiving ATC-CT had a positive impact on high risk ER− BC patients with SPAG5 protein + expression as SPAG5+ protein expression showed 72–65% less of death, recurrence and metastases compared to SPAG5−; p < 0.0001. The positive impact of ATC-CT on SPAG5+BC has also been confirmed in HER2+ who either received ATC-CT only or ACT-CT plus Herceptin. iv) Moreover, BC received neoadjuvantATC-CT, SPAG5+ BC achieved 39% pCR vs., 6% of SPAG5-negative BC (p < 0.00001). After controlling to other validated predictors for pCR, SPAG5 remained as a powerful independent predictor (HR; 2.4, CI 95%; 1.5–3.9; p = 0.00001).

Conclusion: SPAG5 is an important novel gene implicated in the survival of BC cells and its protein expression is an independent predictor for ATC- CT. SPAG5 may provide new avenues for the discovery of new predictive marker to guide therapeutic intervention.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-18.

Chronic hydrocarbon exposure of harlequin ducks in areas affected by the Selendang Ayu oil spill at Unalaska Island, Alaska

We evaluated chronic exposure of harlequin ducks (Histrionicus histrionicus) to hydrocarbons associated with the 2004 M/V Selendang Ayu oil spill at Unalaska Island, Alaska. We measured levels of hepatic 7-ethoxyresorufin-O-deethylase activity (EROD) in liver biopsy samples as an indicator of hydrocarbon exposure in three oiled bays and one reference bay in 2005, 2006, and 2008. Median EROD activity in ducks from oiled bays was significantly higher than in the reference bay in seven of nine pairwise comparisons. These results indicated that harlequin ducks were exposed to lingering hydrocarbons more than three years after the spill.

Cytochrome P4501A biomarker indication of the timeline of chronic exposure of Barrow's goldeneyes to residual Exxon Valdez oil

We examined hepatic EROD activity, as an indicator of CYP1A induction, in Barrow's goldeneyes captured in areas oiled during the 1989 Exxon Valdez spill and those from nearby unoiled areas. We found that average EROD activity differed between areas during 2005, although the magnitude of the difference was reduced relative to a previous study from 1996/1997, and we found that areas did not differ by 2009. Similarly, we found that the proportion of individuals captured from oiled areas with elevated EROD activity (≥ 2 times unoiled average) declined from 41% in winter 1996/1997 to 10% in 2005 and 15% in 2009. This work adds to a body of literature describing the timelines over which vertebrates were exposed to residual Exxon Valdez oil and indicates that, for Barrow's goldeneyes in Prince William Sound, exposure persisted for many years with evidence of substantially reduced exposure by 2 decades after the spill.

Cytochrome P4501A biomarker indication of oil exposure in harlequin ducks up to 20 years after the Exxon Valdez oil spill

Hydrocarbon-inducible cytochrome P4501A (CYP1A) expression was measured, as ethoxyresorufin-O-deethylase (EROD) activity, in livers of wintering harlequin ducks (Histrionicus histrionicus) captured in areas of Prince William Sound, Alaska, USA, oiled by the 1989 Exxon Valdez spill and in birds from nearby unoiled areas, during 2005 to 2009 (up to 20 years following the spill). The present work repeated studies conducted in 1998 that demonstrated that in harlequin ducks using areas that received Exxon Valdez oil, EROD activity was elevated nearly a decade after the spill. The present findings strongly supported the conclusion that average levels of hepatic EROD activity were higher in ducks from oiled areas than those from unoiled areas during 2005 to 2009. This result was consistent across four sampling periods; furthermore, results generated from two independent laboratories using paired liver samples from one of the sampling periods were similar. The EROD activity did not vary in relation to age, sex, or body mass of individuals, nor did it vary strongly by season in birds collected early and late in the winter of 2006 to 2007, indicating that these factors did not confound inferences about observed differences between oiled and unoiled areas. We interpret these results to indicate that harlequin ducks continued to be exposed to residual Exxon Valdez oil up to 20 years after the original spill. This adds to a growing body of literature suggesting that oil spills have the potential to affect wildlife for much longer time frames than previously assumed.

Temporal and spatial distributions of sediment mercury at salt pond wetland restoration sites, San Francisco Bay, CA, USA

Decommissioned agricultural salt ponds within south San Francisco Bay, California, are in the process of being converted to habitat for the benefit of wildlife as well as water management needs and recreation. Little is known of baseline levels of contaminants in these ponds, particularly mercury (Hg), which has a well established legacy in the Bay. In this study we described spatial and short-term temporal variations in sediment Hg species concentrations within and among the Alviso and Eden Landing salt ponds in the southern region of San Francisco Bay. We determined total Hg (Hg(t)) and methylmercury (MeHg) in the top 5 cm of sediment of most ponds in order to establish baseline conditions prior to restoration, sediment Hg(t) concentrations in a subset of these ponds after commencement of restoration, and variation in MeHg concentrations relative to sediment Hg(t), pH, and total Fe concentrations and water depth and salinity in the subset of Alviso ponds. Inter-pond differences were greatest within the Alviso pond complex, where sediment Hg(t) concentrations averaged (arithmetic mean) 0.74 microg/g pre and 1.03 microg/g post-restoration activity compared to 0.11 microg/g pre and post at Eden Landing ponds. Sediment Hg(t) levels at Alviso were fairly stable temporally and spatially, whereas MeHg levels were variable relative to restoration activities across time and space. Mean (arithmetic) sediment MeHg concentrations increased (2.58 to 3.03 ng/g) in Alviso and decreased (2.20 to 1.03 ng/g) in Eden Landing restoration ponds during the study. Differences in MeHg levels were related to water depth and pH, but these relationships were not consistent between years or among ponds and were viewed with caution. Factors affecting MeHg levels in these ponds (and in general) are highly complex and require in-depth study to understand.

Invertebrate mercury bioaccumulation in permanent, seasonal, and flooded rice wetlands within California's Central Valley

We examined methylmercury (MeHg) bioavailability in four of the most predominant wetland habitats in California's Central Valley agricultural region during the spring and summer: white rice, wild rice, permanent wetlands, and shallowly-flooded fallow fields. We sampled MeHg and total mercury (THg) concentrations in two aquatic macroinvertebrate taxa at the inlets, centers, and outlets of four replicated wetland habitats (8 wetlands total) during two time periods bounding the rice growing season and corresponding to flood-up and pre-harvest (96 total samples). In general, THg concentrations (mean+/-standard error) in Notonectidae (Notonecta, back swimmers; 1.18+/-0.08 microg g(-1) dry weight [dw]) were higher than in Corixidae (Corisella, water boatmen; 0.89+/-0.06 microg g(-)(1)dw, MeHg: 0.74+/-0.05 microg g(-)(1)dw). MeHg concentrations were correlated with THg concentrations in Corixidae (R(2)=0.80) and 88% of THg was in the MeHg form. Wetland habitat type had an important influence on THg concentrations in aquatic invertebrates, but this effect depended on the sampling time period and taxa. In particular, THg concentrations in Notonectidae, but not Corixidae, were higher in permanent wetlands than in white rice, wild rice, or shallowly-flooded fallow fields. THg concentrations in Notonectidae were higher at the end of the rice growing season than near the time of flood-up, whereas THg concentrations in Corixidae did not differ between time periods. The effect of wetland habitat type was more prevalent near the end of the rice growing season, when Notonectidae THg concentrations were highest in permanent wetlands. Additionally, invertebrate THg concentrations were higher at water outlets than at inlets of wetlands. Our results indicate that although invertebrate THg concentrations increased from the time of flood-up to draw-down of wetlands, temporarily flooded habitats such as white rice, wild rice, and shallowly-flooded fallow fields did not have higher THg or MeHg concentrations in invertebrates than permanent wetlands.

Cancer/testis antigens for therapeutic use

Since van der Bruggen and colleagues first identified specific human tumour-associated antigens of the MAGE family, numerous potential immunotherapeutic targets have been discovered, often belonging to the so-called cancer/ testis gene family. Several members of this group have been described as immunogenic and have been utilised in clinical trials. In a search for interesting targets within this family, our laboratory has focussed its works for a number of years on two novel cancer/testis antigens called T21 and HAGE. In this article, we will focus our discussion on their levels of expression in a wide variety of both normal and cancer tissues, their possible role in tumour cell development and proliferation, and their immunogenic potential.

Organochlorine contaminants in fishes from coastal waters west of Amukta Pass, Aleutian Islands, Alaska, USA

Organochlorines were examined in liver and stable isotopes in muscle of fishes from the western Aleutian Islands, Alaska, in relation to islands or locations affected by military occupation. Pacific cod (Gadus macrocephalus), Pacific halibut (Hippoglossus stenolepis), and rock greenling (Hexagrammos lagocephalus) were collected from nearshore waters at contemporary (decommissioned) and historical (World War II) military locations, as well as at reference locations. Total (Sigma) polychlorinated biphenyls (PCBs) dominated the suite of organochlorine groups (SigmaDDTs, Sigmachlordane cyclodienes, Sigmaother cyclodienes, and Sigmachlorinated benzenes and cyclohexanes) detected in fishes at all locations, followed by SigmaDDTs and Sigmachlordanes; dichlorodiphenyldichloroethylene (p,p'DDE) composed 52 to 66% of SigmaDDTs by species. Organochlorine concentrations were higher or similar in cod compared to halibut and lowest in greenling; they were among the highest for fishes in Arctic or near Arctic waters. Organochlorine group concentrations varied among species and locations, but SigmaPCB concentrations in all species were consistently higher at military locations than at reference locations. Moreover, all organochlorine group concentrations were higher in halibut from military locations than those from reference locations. A wide range of molecular weight organochlorines was detected at all locations, which implied regional or long-range transport and deposition, as well as local point-source contamination. Furthermore, a preponderance of higher-chlorinated PCB congeners in fishes from contemporary military islands implied recent exposure. Concentrations in all organochlorine groups increased with delta15N enrichment in fishes, and analyses of residual variation provided further evidence of different sources of SigmaPCBs and p,p'DDE among species and locations.

Serum biomarker profiling in cancer studies: a question of standardisation?

Companion animals are exposed to similar environmental conditions and carcinogens as humans. In some animal cancers, there also appears to be the same genetic changes associated as in humans. However, little work has been carried out in cancer biomarker identification in animals. The recent dramatic advances in molecular medicine, genomics, proteomics and translational research will allow biomarker identification, which may provide the best strategies for veterinarians and clinicians to combat disease by early diagnosis and administration of effective treatments. Proteomics may have important applications in cancer diagnosis, prognosis and predictive clinical outcome that could directly change clinical practice by affecting critical elemen-ts of care and management. This review summarizes the advances in proteomics that has propelled us to this exciting age of clinical proteomics, and highlights the future work that is required for this to become a reality. In this review, we will discuss the available proteomic technologies and their limitations, and highlight the key areas of research and how they have been used to discover cancer biomarkers. The principles described here are equally applicable to human and animal disease, but implementation of 'omic' technologies requires stringent guidelines for collection of clinical material, the application of analytical techniques and interpretation of the data.

Potential effects of mercury on threatened California black rails

San Francisco Bay (SFB) estuary sediments contain high levels of mercury (Hg), and tidal marsh resident species may be vulnerable to Hg contamination. We examined Hg concentrations in California black rails, a threatened waterbird species that inhabits SFB tidal salt marshes. We captured 127 black rails during the prebreeding and postbreeding seasons and examined the influence of site, sex, and year on Hg, methylmercury (MeHg), and also selenium (Se) concentrations in feathers and blood. Feather Hg concentrations averaged 6.94 microg/g dry weight (dw) and MeHg and Se concentrations in blood averaged 0.38 and 0.42 microg/g wet weight (ww). We used Akaike's information criterion model selection process to evaluate the importance of year, site, sex, and age on patterns of MeHg concentrations; sex and year were the most important of these factors. Feather Hg concentrations (dw) were higher in males (8.22 microg/g) than females (6.63 microg/g) and higher in adult birds (7.36 microg/g) than in hatch-year birds (4.61 microg/g). A substantial portion of SFB black rail populations may be at risk of reproductive effects due to MeHg contamination, as 32-78% of feathers and <10% of blood samples exceeded no observed adverse effect levels. Sea level rise and other anthropogenic threats to endemic tidal marsh species such as black rails may be exacerbated by the presence of MeHg. Further study of population demographics and toxicological effects would further elucidate the effects of MeHg contamination on black rail populations in SFB.

Sources of organochlorine contaminants and mercury in seabirds from the Aleutian archipelago of Alaska: inferences from spatial and trophic variation

Persistent organochlorine compounds and mercury (Hg) have been detected in numerous coastal organisms of the Aleutian archipelago of Alaska, yet sources of these contaminants are unclear. We collected glaucous-winged gulls, northern fulmars, and tufted puffins along a natural longitudinal gradient across the western and central Aleutian Islands (Buldir, Kiska, Amchitka, Adak), and an additional 8 seabird species representing different foraging and migratory guilds from Buldir Island to evaluate: 1) point source input from former military installations, 2) westward increases in contaminant concentrations suggestive of distant source input, and 3) effects of trophic status (delta15N) and carbon source (delta13C) on contaminant accumulation. Concentrations of Sigma polychlorinated biphenyls (PCBs) and most chlorinated pesticides in glaucous-winged gulls consistently exhibited a 'U'-shaped pattern of high levels at Buldir and the east side of Adak and low levels at Kiska and Amchitka. In contrast, concentrations of Sigma PCBs and chlorinated pesticides in northern fulmars and tufted puffins did not differ among islands. Hg concentrations increased westward in glaucous-winged gulls and were highest in northern fulmars from Buldir. Among species collected only at Buldir, Hg was notably elevated in pelagic cormorants, and relatively high Sigma PCBs were detected in black-legged kittiwakes. Concentrations of Sigma PCBs, dichlorodiphenyldichloroethylene (p,p' DDE), and Hg were positively correlated with delta15N across all seabird species, indicating biomagnification across trophic levels. The east side of Adak Island (a former military installation) was a likely point source of Sigma PCBs and p,p' DDE, particularly in glaucous-winged gulls. In contrast, elevated levels of these contaminants and Hg, along with PCB congener and chlorinated pesticide compositional patterns detected at Buldir Island indicated exposure from distant sources influenced by a combination of atmospheric-oceanic processes and the migratory movements of seabirds.

Mercury correlations among six tissues for four waterbird species breeding in San Francisco Bay, California, USA

Despite a large body of research concerning mercury (Hg) in birds, no single tissue has been used consistently to assess Hg exposure, and this has hampered comparisons across studies. We evaluated the relationships of Hg concentrations among tissues in four species of waterbirds (American avocets [Recurvirostra americana], black-necked stilts [Himantopus mexicanus], Caspian terns [Hydroprogne caspia; formerly Sterna caspia], and Forster's terns [Sterna forsteri]) and across three life stages (prebreeding adults, breeding adults, and chicks) in San Francisco Bay, California, USA. Across species and life stages, Hg concentrations (least square mean +/- standard error) were highest in head feathers (6.45 +/- 0.31 microg/g dry wt) and breast feathers (5.76 +/- 0.28 microg/g dry wt), followed by kidney (4.54 +/- 0.22 microg/g dry wt), liver (4.43 +/- 0.21 microg/g dry wt), blood (3.10 +/- 0.15 microg/g dry wt), and muscle (1.67 +/- 0.08 microg/g dry wt). Relative Hg distribution among tissues, however, differed by species and life stage. Mercury concentrations were highly correlated among internal tissues (r2 > or = 0.89). Conversely, the relationships between Hg in feathers and internal tissues were substantially weaker (r2 < or = 0.42). Regression slopes sometimes differed among species and life stages, indicating that care must be used when predicting Hg concentrations in one tissue based on those in another. However, we found good agreement between predictions made using a general tissue-prediction equation and more specific equations developed for each species and life stage. Finally, our results suggest that blood is an excellent, nonlethal predictor of Hg concentrations in internal tissues but that feathers are relatively poor indicators of Hg concentrations in internal tissues.

Timing of Fungicide Applications for Control of Husk Spot Caused by Pseudocercospora macadamiae in Macadamia

Pseudocercospora macadamiae is an important pathogen of macadamia in Australia, causing a disease known as husk spot. Growers strive to control the disease with a number of carbendazim and copper treatments. The aim of this study was to consider the macadamia fruit developmental stage at which fungicide application is most effective against husk spot, and whether application of copper-only applications at full-size fruit developmental stage toward the end of the season contributed to effective disease control. Fungicides were applied to macadamia trees at four developmental stages in three orchards in two subsequent production seasons. The effects of the treatments on disease incidence and severity were quantified using area under disease progress curve (AUDPC) and logistic regression models. Although disease incidence varied between cultivars, incidence and severity on cv. A16 showed consistent differences between the treatments. Most significant reduction in husk spot incidence occurred when spraying commenced at match-head sized-fruit developmental stage. All treatments significantly reduced husk spot incidence and severity compared with the untreated controls, and a significant positive linear relationship (R² = 73%) between AUDPC and severity showed that timing of the first fungicide application is important for effective disease control. Application of fungicide at full-size fruit stage reduced disease incidence but had no impact on premature fruit drop.

Polycyclic aromatic hydrocarbon exposure in Steller's eiders (Polysticta stelleri) and Harlequin ducks (Histronicus histronicus) in the eastern Aleutian Islands, Alaska, USA

Seaducks may be affected by harmful levels of polycyclic aromatic hydrocarbons (PAHs) at seaports near the Arctic. As an indicator of exposure to PAHs, we measured hepatic enzyme 7-ethoxyresorufin-O-deethylase activity (EROD) to determine cytochrome P4501A induction in Steller's eiders (Polysticta stelleri) and Harlequin ducks (Histronicus histronicus) from Unalaska, Popof, and Unga Islands (AK, USA) in 2002 and 2003. We measured PAHs and organic contaminants in seaduck prey samples and polychlorinated biphenyl congeners in seaduck blood plasma to determine any relationship to EROD. Using Akaike's information criterion, species and site differences best explained EROD patterns: Activity was higher in Harlequin ducks than in Steller's eiders and higher at industrial than at nonindustrial sites. Site-specific concentrations of PAHs in blue mussels ([Mytilus trossilus] seaduck prey; PAH concentrations higher at Dutch Harbor, Unalaska, than at other sites) also was important in defining EROD patterns. Organochlorine compounds rarely were detected in prey samples. No relationship was found between polychlorinated biphenyl congeners in avian blood and EROD, which further supported inferences derived from Akaike's information criterion. Congeners were highest in seaducks from a nonindustrial or reference site, contrary to PAH patterns. To assist in interpreting the field study, 15 captive Steller's eiders were dosed with a PAH known to induce cytochrome P4501A. Dosed, captive Steller's eiders had definitive induction, but results indicated that wild Steller's eiders were exposed to PAHs or other inducing compounds at levels greater than those used in laboratory studies. Concentrations of PAHs in blue mussels at or near Dutch Harbor (approximately 1,180-5,980 ng/g) approached those found at highly contaminated sites (approximately 4,100-7,500 ng/g).

Mercury concentrations and space use of pre-breeding American avocets and black-necked stilts in San Francisco Bay

We examined factors influencing mercury concentrations in pre-breeding American avocets (Recurvirostra americana) and black-necked stilts (Himantopus mexicanus), the two most abundant breeding shorebirds in San Francisco Bay, California. We tested the effects of species, site, sex, year, and date on total mercury concentrations in blood of pre-breeding adult birds and used radio telemetry to determine space use and sites of dietary mercury exposure. We collected blood from 373 avocets and 157 stilts from February to April in 2005 and 2006, radio-marked and tracked 115 avocets and 94 stilts, and obtained 2393 avocet and 1928 stilt telemetry locations. Capture site was the most important factor influencing mercury concentrations in birds, followed by species and sex. Mercury concentrations were higher in stilts (geometric mean: 1.09 microg g(-1) wet weight [ww]) than in avocets (0.25 microg g(-1) ww) and males (stilts: 1.32 microg g(-1) ww; avocets: 0.32 microg g(-1) ww) had higher levels than females (stilts: 1.15 microg g(-1) ww; avocets: 0.21 microg g(-1) ww). Mercury concentrations were highest for both species at the southern end of San Francisco Bay, especially in salt pond A8 (stilts: 3.31 microg g(-1) ww; avocets: 0.58 microg g(-1) ww). Radio telemetry data showed that birds had strong fidelity to their capture site. Avocets primarily used salt ponds, tidal marshes, tidal flats, and managed marshes, whereas stilts mainly used salt ponds, managed marshes, and tidal marshes. Our results suggest that variation in blood mercury concentrations among sites was attributed to differences in foraging areas, and species differences in habitat use and foraging strategies may increase mercury exposure in stilts more than avocets.

Environmental contaminants in bald eagle eggs from the Aleutian archipelago

We collected 136 fresh and unhatched eggs from bald eagle (Haliaeetus leucocephalus) nests and assessed productivity on eight islands in the Aleutian archipelago, 2000 to 2002. Egg contents were analyzed for a broad spectrum of organochlorine (OC) contaminants, mercury (Hg), and stable isotopes of carbon (delta13C) and nitrogen (delta15N). Concentrations of polychlorinated biphenyls (SigmaPCBs), p,p'-dichlorodiphenyldichloroethylene (DDE), and Hg in bald eagle eggs were elevated throughout the archipelago, but the patterns of distribution differed among the various contaminants. Total PCBs were highest in areas of past military activities on Adak and Amchitka Islands, indicating local point sources of these compounds. Concentrations of DDE and Hg were higher on Amchitka Island, which was subjected to much military activity during World War II and the middle of the 20th century. Concentrations of SigmaPCBs also were elevated on islands with little history of military activity (e.g., Amlia, Tanaga, Buldir), suggesting non-point sources of PCBs in addition to point sources. Concentrations of DDE and Hg were highest in eagle eggs from the most western Aleutian Islands (e.g., Buldir, Kiska) and decreased eastward along the Aleutian chain. This east-to-west increase suggested a Eurasian source of contamination, possibly through global transport and atmospheric distillation and/or from migratory seabirds. Eggshell thickness and productivity of bald eagles were normal and indicative of healthy populations because concentrations of most contaminants were below threshold levels for effects on reproduction. Contrary to our predictions, contaminant concentrations were not correlated with stable isotopes of carbon (delta13C) or nitrogen (delta15N) in eggs. These latter findings indicate that contaminant concentrations were influenced more by point sources and geographic location than trophic status of eagles among the different islands.

Expressed MHC class II genes in sea otters (Enhydra lutris) from geographically disparate populations

The major histocompatibility complex (MHC) is central to maintaining the immunologic vigor of individuals and populations. Classical MHC class II genes were targeted for partial sequencing in sea otters (Enhydra lutris) from populations in California, Washington, and Alaska. Sequences derived from sea otter peripheral blood leukocyte mRNAs were similar to those classified as DQA, DQB, DRA, and DRB in other species. Comparisons of the derived amino acid compositions supported the classification of these as functional molecules from at least one DQA, DQB, and DRA locus and at least two DRB loci. While limited in scope, phylogenetic analysis of the DRB peptide-binding region suggested the possible existence of distinct clades demarcated by geographic region. These preliminary findings support the need for additional MHC gene sequencing and expansion to a comprehensive study targeting additional otters.

Effects of trichloroethylene and perchloroethylene on wild rodents at Edwards Air Force Base, California, USA

Effects of inhalation of volatilized trichloroethylene (TCE) or perchloroethylene (PCE) were assessed based on the health and population size of wild, burrowing mammals at Edwards Air Force Base (CA, USA). Organic soil-vapor concentrations were measured at three sites with aquifer contamination of TCE or PCE of 5.5 to 77 mg/L and at two uncontaminated reference sites. Population estimates of kangaroo rats (Dipodomys merriami and D. panamintinus) as well as hematology, blood chemistry, and histopathology of kangaroo rats and deer mice (Peromyscus maniculatus) were compared between contaminated and uncontaminated populations. Maximum soil-gas concentrations associated with groundwater contamination were less than 1.5 microl/L of TCE and 0.07 microl/L of PCE. Population estimates of kangaroo rats were similar at contaminated and reference sites. Hematology, blood chemistry, and histopathology of kangaroo rats and deer mice indicated no evidence of health effects caused by exposure. Trichloroethylene or PCE in groundwater and in related soil gas did not appear to reduce the size of small mammal populations or impair the health of individuals.

Effects of the mosquito larvicide GB-1111 on bird eggs

Golden Bear Oil (GB-1111; legal trade name for GB-1313) is a petroleum distillate used in the United States and other countries as a mosquito larvicide. As part of an evaluation of the potential effects of GB-1111 on birds, fertile eggs of mallards (Anas platyrhynchos) and bobwhite (Colinus virginianus) were incubated in the laboratory, and treated on day 4 of incubation with external applications equivalent to either 0, 1/3, 1, 3 or 10 times the maximum rate (X) of 47 l/ha (5 gal/A) of field application of GB-1111. Hatching success was significantly reduced in mallards treated at 3 and 10 times the maximum field application, with a calculated approximate LD50 of 1.9 times the maximum field application. Most mortality occurred within a week of treatment. Hepatic P450-associated monooxygenase activity (ethoxyresorufin-O-dealkylase; EROD) was negatively related to dose. In the 3X group there was a significant increase in the concentration of hepatic reduced glutathione (GSH) but a decrease in protein-bound thiols (PBSH). Hatching success of bobwhite was marginally reduced at the highest level of treatment (10X). Other effects at this level in bobwhite included a significant increase in incidence of abnormal embryos or hatchlings, lower body and liver weights, and a two-fold increase in hepatic microsomal EROD activity in hatchlings. The recommended maximum rate of field application of GB-1111 is unlikely to impair the survival or development of bobwhite embryos but is potentially toxic to mallard embryos under conditions of larvicide drift or spray overlap.

Spatial and temporal heterogeneity in metallic elements in industrialized aquatic bird habitats

This study examined the potential for exposure of migratory aquatic birds to contaminants in highly industrialized habitats at Baltimore Harbor, Maryland. Seven nearshore, benthic sites were sampled every 3 or 6 months from June 1987 to December 1988. Twenty metallic elements were measured in composites (i.e. annelids, amphipods, and isopods were pooled), clams, and sediments. Elevated concentrations were widespread throughout the sites, depending on the element. Most concentrations in composites were lowest at sites innermost and outside the harbor. Higher concentrations in composites were not related to season. Most concentrations were higher in composites than in sediments or clams, but they varied by element for clams and sediments. The largest flock of wintering waterfowl frequented the site exhibiting the highest concentrations of most elements ( [Formula: see text] ). Average concentrations of known toxic elements were probably not harmful to aquatic birds or their prey, but the highest detected concentrations of eight elements warrant caution. At least eight other elements exceeded background concentrations, but toxicity to birds or their prey are unknown.