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Environmental agent susceptibility assessment using existing and novel biomarkers as rapid noninvasive testing methods.

This study is part of a project aimed at developing and validating novel noninvasive methods for the detection of biomarkers of endocrine disrupters (EDs) directly in the mucus of aquatic species, to identify novel functional biomarker(s) for EDs, and to verify their applicability for field studies. The multidisciplinary approach chosen aims at the development of an integrated testing strategy utilizing in vitro protocols to identify water and sediment fractions with potential endocrine-disrupting activity; the identification, characterization, and measurement of new biomarker(s) for EDs; the development and validation of a dipstick-based test method; and the development of (computer-assisted) predictive models. Some results of the first year of the project are presented here.

Animals↗

Urine cotinine as an index of smoking status in smokers during 96-hr abstinence: comparison between gas chromatography/mass spectrometry and immunoassay test strips.

Biomarkers such as carbon monoxide (CO) and cotinine (a nicotine metabolite) are used in tobacco cessation studies to assess smoking status. CO is easy to assess, is inexpensive, and provides immediate results. However, the short half-life of CO may limit its ability to identify smokers who have abstained for several hours. Quantitative methods (e.g., gas chromatography/mass spectrometry, or GC/MS) for measuring urine cotinine, which has a longer half-life, are valid and reliable, though costly and time consuming. Recently developed semiquantitative urine cotinine measurement techniques (i.e., urine immunoassay test strips, or ITS) address these disadvantages, though the value of ITS as a means of identifying abstaining smokers has not been evaluated. The present study examined ITS as a measure of smoking status in temporarily abstaining smokers. A total of 236 breath and urine samples were collected from smokers who participated in two separate studies involving three independent, 96-hr (i.e., Monday-Friday), Latin-square-ordered, abstinence or smoking conditions; a minimum 72-hr washout separated each condition. Each urine sample was analyzed with GC/MS and ITS. Under these study conditions, CO demonstrated moderate sensitivity (83.1%) and strong specificity (100%), whereas ITS assessment showed strong sensitivity (98.5%) and weak specificity (58.5%). In this study of short-term abstinence, ITS classified as nonabstinent nearly half of the samples collected from abstaining smokers. However, it classified nearly all nonabstinent smokers as currently smoking. Validation of ITS using GC/MS results from smokers undergoing more than 96 hr of abstinence may be valuable.

Adult↗

Cloning and real-time PCR testing of 14 potential biomarkers in Eisenia fetida following cadmium exposure.

Important biological activities could be affected in metal exposed species, and amongthe main physiological functions, immunity may provide one (or more) effector(s) which expression can be directly affected by a metal exposure in various macroinvertebrates. As many proteinic effectors showed a high degree of homology between species, we have developed a PCR approach to characterize partial mRNA sequences of selected effectors in the laboratory model, Eisenia fetida. After cloning, levels of expression of each gene were analyzed following exposures (80 and 800 mg/kg) to cadmium spiked soils using real-time PCR. An implemented approach was allowed to test quickly potential biomarkers in Eisenia fetida. Selected effectors were calmodulin, heat shock proteins, superoxide dismutase, catalase, metallothionein, beta-adrenergic receptor kinase, pyruvate carboxylase, trancriptionally controlled tumor protein, protein kinase C, and ubiquitin. Most of the selected effectors did not show variations of expression level after exposure. Others expressed weak changes of expression as heat shock proteins. At lastfor catalase and metallothionein, early suitable variations of expression were observed.

Animals↗

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗

The erythrocyte adhesiveness/aggregation test (EAAT). A new biomarker to reveal the presence of low grade subclinical smoldering inflammation in individuals with atherosclerotic risk factors.

BACKGROUND: Multiple acute phase proteins and atherosclerotic risk factors increase the aggregability of erythrocytes. METHODS AND RESULTS: We used a simple slide test and image analysis to determine the degree of erythrocyte adhesiveness/aggregation in the peripheral blood of 222 women and 221 men with no, one, two or more atherosclerotic risk factors. The degree of erythrocyte adhesiveness/aggregation correlated significantly with the concentration of commonly used variables of the acute phase response. We also showed that individuals with low erythrocyte adhesiveness/aggregation tend to be younger and to have fewer risk factors for atherosclerosis, including diabetes mellitus, hypertension, hyperlipidemia and smoking. CONCLUSIONS: The association between increased erythrocyte adhesiveness/aggregation, higher concentrations of acute phase proteins, and increased atherosclerotic risk factors points to a possible clinical applicability of the erythrocyte adhesiveness/aggregation test (EAAT) to reveal the presence of both low-grade subclinical smoldering inflammation and morbid biology in individuals with risk factors for atherosclerosis.

Adult↗

A review of current literature on physiological tests and soft tissue biomarkers applicable to work-related upper limb disorders.

Work-related upper limb disorders (WRULD) are among the most commonly reported occupational illnesses. Epidemiological evidence of work-relatedness has been reported for a number of conditions, including carpal tunnel syndrome, hand/wrist tendinitis, shoulder tendinitis and hand-arm vibration syndrome. A range of electrodiagnostic techniques and psychophysical tests has been used to assess neurological dysfunction associated with WRULD, whereas only very few studies have examined biochemical markers of soft tissue injury. This report reviews key literature on physiological tests and biochemical markers of musculoskeletal stress/injury, which are applicable to studies of WRULD. The paper concludes by proposing new ways that testing might be implemented during occupational health surveillance to enable early warning of impending problems and to provide more insight into the underlying nature of soft tissue disorders.

Arm Injuries↗

Link test--A statistical method for finding prostate cancer biomarkers.

We present a new method, link-test, to select prostate cancer biomarkers from SELDI mass spectrometry and microarray data sets. Biomarkers selected by link-test are supported by data sets from both mRNA and protein levels, and therefore results in improved robustness. Link-test determines the level of significance of the association between a microarray marker and a specific mass spectrum marker by constructing background mass spectra distributions estimated by all human protein sequences in the SWISS-PROT database. The data set consist of both microarray and mass spectrometry data from prostate cancer patients and healthy controls. A list of statistically justified prostate cancer biomarkers is reported by link-test. Cross-validation results show high prediction accuracy using the identified biomarker panel. We also employ a text-mining approach with OMIM database to validate the cancer biomarkers. The study with link-test represents one of the first cross-platform studies of cancer biomarkers.

Algorithms↗

Progress in biomarker discovery for diagnostic testing in epithelial ovarian cancer.

Ovarian cancer accounts for more deaths than all other gynecological malignancies combined, primarily due to advanced stage at initial presentation and our continued inability to detect early-stage disease. Multiple approaches have led to the development of new diagnostic markers for early detection, with no real success (high false positives and poor positive predictive values). Considering the rarity of this disease, the impact of poor diagnostic markers will only be detrimental to the entire early-detection process. Recent advances in proteomics, as well as breakthroughs in analytical techniques and bioinformatics, have enabled researchers to look outside the box, for a panel of proteins (protein profiles) rather than just one or two proteins, thus increasing sensitivity and specificity. This review describes current strategies in the early detection of ovarian cancer, existing markers, their clinical utilities and shortcomings, and highlights newer markers and technologies that are being pursued to improve women's healthcare.

Biomarkers↗

Evidence from biomarkers and surrogate endpoints.

The use of physiological, anatomical, and other biological tests is commonplace in the practice of medicine. In neurology, objectively measured tests termed biomarkers (BMs) are playing an increasing role in diagnosis and management of disease, both in clinical practice and in experimental therapeutics. This article will discuss the various applications of BMs to the assessment of therapies for neurological diseases and will use examples from neurological diseases to elucidate the strengths and potential weaknesses of BMs. As the understanding of the pathophysiology of many neurological diseases has improved, new BMs have been developed, and efforts have been made to use these as proxies for clinical endpoints. A BM used in this manner is referred to as a surrogate endpoint (SE). There are many potential advantages and disadvantages of using SEs in the evaluation of new therapies, and these will be reviewed as well. Furthermore, the evidence required for the development of an SE and the nature of the evidence that can be derived from the use of BMs and SEs will be discussed.

Animals↗

Takotsubo Syndrome: The First Non-Acute Proteomic Analysis by Remote Dried Blood Microsampling.

Takotsubo syndrome (TTS) is an under-recognized form of acute-onset heart failure typically precipitated by stress. While recovery of cardiac function is described over the course of weeks, adverse outcomes after apparent recovery are increasingly recognized. However, the pathophysiology of non-acute manifestations remains poorly understood. We used mass-spectrometry-based discovery proteomics from remotely collected non-acute dried blood microsamples to perform a case-control study in 62 participants with a prior TTS episode (median of 2.24 years prior to sample collection) and 47 reference controls. We quantified 398 unique proteins, and found that agnostic clustering techniques showed separation between TTS and reference control samples. This represents the first proteomic characterization of non-acute TTS. Pathway analysis of the 52 differentially regulated proteins demonstrated enrichment of proteins involved in complement activation, nitric oxide signaling, and with antioxidant activity. These enriched pathways may be suggestive of a persistent cardiomyopathy resulting from or predisposing to TTS.

Humans↗

Biomarker responses at different levels of biological organisation in crabs (Carcinus aestuarii) experimentally exposed to benzo(alpha)pyrene.

The aim of this study was to validate a multi-trial biomarker approach for the evaluation of toxicological risk due to benzo(alpha)pyrene. Carcinus aestuarii, exposed to increasing concentrations of B(alpha)P in the water, was used as the bioindicator organism. A set of biomarkers were tested in order to: identify biological materials for biomarker and residue analysis; determine a group of sensitive techniques for the assessment of PAH contamination; investigate correlation between responses at different levels of biological organisation. The results underlined that BPMO activities in hepatopancreas and gills were a good biomarker of exposure to PAH-type compounds. B esterases activities in hemolymph and porphyrin patterns in excreta could be proposed as a non-destructive approach for evaluating chemical exposure in this species.

Animals↗

MIP-1beta, a novel biomarker for in vitro sensitization test using human monocytic cell line.

In order to seek a novel biomarker for predicting skin sensitization, changes in the gene expression profile of THP-1 cells on exposure to 2,4-dinitrochlorobenzene (DNCB), p-phenylenediamine (pPD) and nickel sulfate (Ni) were assessed using oligo-DNA microarrays. While the change in gene expression varied depending on the sensitizers, up-regulation of MIP-1 beta mRNA expression was detected in both DNCB-treated and Ni-treated THP-1 cells. This finding was validated by RT-PCR and confirmed at the protein level by ELISA. Secretion of MIP-1 beta from THP-1 was detected after 24-h treatment with sensitizers such as DNCB, Ni, 2-mercaptobenzothiazole (2-MBT) and cobalt sulfate (Co), while pPD and non-sensitizers such as sodium dodecyl sulfate (SDS) and benzalkonium chloride (BC) had no effect. The use of both MIP-1 beta production and CD86 expression as criteria reduced the number of false-negatives, and the results were in good agreement with those of in vivo assays. MIP-1 beta may be useful as a novel biomarker in in vitro sensitization assay using THP-1 cells, either alone or in combination with known markers.

B7-2 Antigen↗

[Idiopathic rhinitis].

Idiopathic Rhinitis (IR) is a term for a group of nasal diseases of unknown aetiology. Formerly, these diseases were called vasomotor rhinitis, but because there is no indication of a disorder in the vasomotor system, this term has been abandoned. Other terms, like non-infectious non-allergic rhinitis and non-allergic non-infectious perennial rhinitis are purely descriptive. Potential pathomechanisms in IR could be 1) neural dysfunction/dysregulation; 2) immunological inflammatory responses; and 3) changes of the permeability of the mucosa, leading to increase entrance of potential harmful substances. Idiopathic Rhinitis is a diagnosis by exclusion, meaning that a number of more or less defined nasal conditions as a cause of rhinitis have been excluded - not only allergic rhinitis. Although a considerable progress was made in the standardization of provocation tests or biomarkers in nasal secretions, there are today no specific test available to confirm the diagnosis rhinitis in many non allergic conditions. An evidence-based review of treatment outcomes shows topical sprays of steroids, antihistamines to be of benefit in idiopathic rhinitis. Furthermore, nasal saline solution is effective in many patients with IR. Multiple surgical procedures have been suggested for IR, but should be reserved for patients who fail medical therapy.

Adrenal Cortex Hormones↗

Human behavioral assessment in neurotoxicology: producing appropriate test performance with written and shaping instructions.

Neurotoxic effects are of such breadth and complexity that functional biomarkers (behavioral tests) that integrate many areas of the nervous system predominate in human neurotoxicology research. The increasing distribution of chemical and other manufacturing throughout the world, particularly in developing nations, suggests the acute need to develop biomarkers for chemical exposures and effects that can be employed internationally. A language-free method for training performance on behavioral tests is described, which holds promise for international research that circumvents the vagaries of translation. Four behavioral tests were administered to 74-114 adult US subjects. Procedures, collectively termed shaping, produced effective performance on three tests [Symbol Digit, Vigilant Attention Test (VAT), Digit Span Forward and Backward], and produced appropriate but unacceptably slow performance in initial testing on the Simple Reaction Time test. Effective performance on the Symbol-Digit test also was produced by shaping instruction, without assistance from examiners, in small groups of residents of Taipei (Taiwan) and US children between the ages of 5 and 16.

Adolescent↗

Biomarkers in cancer screening: a public health perspective.

The last three decades have witnessed a rapid advancement and diffusion of technology in health services. Technological innovations have given health service providers the means to diagnose and treat an increasing number of illnesses, including cancer. In this effort, research on biomarkers for cancer detection and risk assessment has taken a center stage in our effort to reduce cancer deaths. For the first time, scientists have the technologies to decipher and understand these biomarkers and to apply them to earlier cancer detection. By identifying people at high risk of developing cancer, it would be possible to develop intervention efforts on prevention rather than treatment. Once fully developed and validated, then the regular clinical use of biomarkers in early detection and risk assessment will meet nationally recognized health care needs: detection of cancer at its earliest stage. The dramatic rise in health care costs in the past three decades is partly related to the proliferation of new technologies. More recent analysis indicates that technological change, such as new procedures, products and capabilities, is the primary explanation of the historical increase in expenditure. Biomarkers are the new entrants in this competing environment. Biomarkers are considered as a competing, halfway or add-on technology. Technology such as laboratory tests of biomarkers will cost less compared with computed tomography (CT) scans and other radiographs. However, biomarkers for earlier detection and risk assessment have not achieved the level of confidence required for clinical applications. This paper discusses some issues related to biomarker development, validation and quality assurance. Some data on the trends of diagnostic technologies, proteomics and genomics are presented and discussed in terms of the market share. Eventually, the use of biomarkers in health care could reduce cost by providing noninvasive, sensitive and reliable assays at a fraction of the cost of definitive technology, such as CT scan. The National Cancer Institute's Early Detection Research Network (EDRN) has begun an innovative, investigator-initiated project to improve methods for detecting the biomarkers of cancer cells. The EDRN is a consortium of more than 32 institutions to link discovery of biomarkers to the next steps in the process of developing early detection tests. These discoveries will lead to early clinical validation of tests with improved accuracy and reliability.

Biomarkers↗

Challenges in drug development for functional gastrointestinal disorders. Part II: visceral pain.

There is a need to have predictive biomarkers to test novel experimental medicines in functional gastrointestinal disorders. The human pharmacodynamic models and biomarkers pertaining to two important conditions are reviewed in a two-part article: functional dyspepsia (part I) and visceral pain (part II). With visceral pain models, the large coefficient of variation in sensation end points in human studies precludes definitive conclusions such as go/no go decisions or dose selection for phase IIb or III studies, unless very large numbers of patients are evaluated in phase IIA pharmacodynamic studies. This renders such pharmacological studies ambitious, or unachievable in a timely fashion. Moreover, the results of tests and clinical trials should be interpreted with greater knowledge of the drug pharmacokinetics, including the influence of CYP metabolism and potential drug interactions. Thus, it is important to identify valid biomarkers of visceral pain for the assessment of treatment response in pharmacodynamic studies. In this second part of a two-part article, we shall discuss the special challenges in developing medications for visceral pain and the general importance of including pharmacokinetic and pharmacogenomic studies in drug development programmes.

Animals↗

Challenges in drug development for functional gastrointestinal disorders. Part I: functional dyspepsia.

There is a need to have predictive biomarkers to test novel experimental medicines in functional gastrointestinal disorders (FGID). The human pharmacodynamic models and biomarkers in functional dyspepsia (part I) and visceral pain (part II) are reviewed, including the general challenges of these two disorders (part I). Part II will also discuss the importance of drug pharmacokinetics and potential of pharmacogenomics, including the influence of CYP metabolism and potential drug interactions. The great heterogeneity of mechanisms potentially responsible for dyspeptic symptoms adds a significant complexity to this FGID. Strategies are needed to identify subgroups most likely to benefit from a specific pharmacological action targeted to one or more mechanisms. Thus, while there are significant challenges in drug development for functional dyspepsia, there is still an important role for pharmacodynamic studies. It remains to be demonstrated that identifying subgroups enhances the response to the pharmacological drug effect. This is feasible as the end points and performance of each test of gastric emptying, accommodation and sensitivity are well characterized. Of these, gastric emptying appears best validated at present, though responsiveness to this biomarker has not yet been translated into positive phase III trials. Eligibility criteria are proposed for selection of patients for functional dyspepsia trials.

Animals↗

Rapid toxicity assessment and biomonitoring of marine contaminants--exploiting the potential of rapid biomarker assays and microscale toxicity tests.

There is a great need for an integrated international effort in research and training using rapid, easy to use, biomarker and microscale ecotoxicity techniques. These techniques must be directed, coordinated and formulated into protocols that contribute to the prevention and reduction of marine pollution world-wide and the improvement of ocean and human health. This need should be considered as urgent by marine environmental scientists, managers and policy makers throughout the world. Our paper discusses such techniques and suggests a four-point framework for advancing work towards their wider use, particularly in developing coastal nations.

Animals↗