Advances In Detection Methods Research Articles

Laboratory studies of organic peroxy radical chemistry: an overview with emphasis on recent issues of atmospheric significance

Organic peroxy radicals (often abbreviated RO(2)) play a central role in the chemistry of the Earth's lower atmosphere. Formed in the atmospheric oxidation of essentially every organic species emitted, their chemistry is part of the radical cycles that control the oxidative capacity of the atmosphere and lead to the formation of ozone, organic nitrates, organic acids, particulate matter and other so-called secondary pollutants. In this review, laboratory studies of this peroxy radical chemistry are detailed, as they pertain to the chemistry of the atmosphere. First, a brief discussion of methods used to detect the peroxy radicals in the laboratory is presented. Then, the basic reaction pathways - involving RO(2) unimolecular reactions and bimolecular reactions with atmospheric constituents such as NO, NO(2), NO(3), O(3), halogen oxides, HO(2), and other RO(2) species - are discussed. For each of these reaction pathways, basic reaction rates are presented, along with trends in reactivity with radical structure. Focus is placed on recent advances in detection methods and on recent advances in our understanding of radical cycling processes, particularly pertaining to the complex chemistry associated with the atmospheric oxidation of biogenic hydrocarbons.

Circulating tumor cells: advances in detection methods, biological issues, and clinical relevance

Circulating tumor cells (CTCs) have long been considered a reflection of tumor aggressiveness. Hematogenous spreading of CTCs from a primary tumor is a crucial step in the metastasis cascade, which leads ultimately to the formation of overt metastases. However, owing to the rarity of CTCs in peripheral blood, detecting these cells requires methods combined with high sensitivity and specificity, which sets tremendous challenges for the implementation of these assays into clinical routine. Generally, CTCs detection methods are composed of the following two steps: enrichment (isolation) process (morphological and immunological techniques) and detection (identification) process (cytometric and nucleic acid techniques), which may or may not be separate from enrichment. Genetic and molecular characterization of CTCs carried out by fluorescent in situ hybridization (FISH), comparative genomic hybridization (CGH), PCR-based techniques, and biomarker immunofluorescent staining extract more information about malignant profile, metastatic potential of CTCs, and the extent to which CTCs are genetically identical to the primary tumor. Recent technical advances made it possible to detect CTCs. The efficacy of circulating tumor cell (CTC) detection among patients with solid malignancy has been investigated, which shows great potential to become a tool for real-time parameter of prognosis and serve as an early marker to assess the therapeutic response in overt cancers. Improvements in detection and characterization of CTCs will hopefully lead to refinement of clinical management of cancer patients. This review addresses the majority of assays that have been published thus far, including the enrichment and detection steps and the markers used in these assays, accompanied by some biological issues of CTC and the results of clinical application harvested.

Abstract 4321: A critical role for IGFBP2 in the progression and maintenance of glioma

Abstract Despite recent advances in detection methods and treatments for other tumor types, the standard of care for glioma patients remains relatively unchanged and survival rates remain dismal. Identification of key signaling nodes that function throughout glioma development will likely provide new targets for intervention. To elucidate the role of the critical oncogene, IGFBP2, in the progression and maintenance of glioma, we generated an inducible mouse model. This model utilizes the RCAS/Tv-a system, which places the Tv-a receptor for the avian RCAS virus under the control of the Nestin promoter to drive Tv-a expression in glial progenitors. The RCAS virus, expressing the desired oncogenes, infects Tv-a expressing cells and delivers the oncogene. By using RCAS to express a tetracycline-responsive IGFBP2 and a tetracycline transactivator, we can modify this system to generate an inducible IGFBP2 model. Using this model, we have tested the hypothesis that IGFBP2 is a key target for glioma therapy due to its important role in glioma maintenance. The studies described here aim to: (1) determine the effects of delayed IGFBP2 expression on the progression of PDGFB-induced, low-grade gliomas; and (2) determine whether continued expression of IGFBP2 is required to maintain the high-grade nature of gliomas induced by the co-expression of PDGFB and IGFBP2. Previously, our lab and others determined that over-expression of PDGFB in glial progenitors led to the development of low-grade glioma. Our lab also determined that IGFBP2 cooperates with PDGFB to promote progression to high-grade glioma. In the inducible model system, tetracycline-mediated IGFBP2 induction in vivo was confirmed by both quantitative RT-PCR of mouse brain tissue and serum ELISA, indicating that RCAS-delivered IGFBP2 is both expressed and secreted upon induction. IGFBP2 induction from birth increased the proportion of tumors that progressed to high-grade glioma, whereas delayed IGFBP2 induction led to later onset of high-grade tumor development. Significantly, there was a decrease in tumor-free survival upon IGFBP2 induction. This is consistent with analysis of transcriptome data from the Rembrandt and TCGA databases. These studies validate an important role for IGFBP2 in the progression of glioma. Ongoing studies using the inducible system are exploring the response of high-grade gliomas to sustained and brief inactivation of IGFBP2. Elucidating the roles of IGFPB2 in glioma progression and maintenance will provide critical information pertinent to the design and implementation of future therapies to target this molecule or associated signaling pathways, as well as how IGFBP2 might be useful as a marker for disease state. Further, these studies may have a more global impact on cancer research as IGFBP2 over-expression has also been associated with other high-grade tumors such as prostate and breast cancers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4321. doi:10.1158/1538-7445.AM2011-4321

Advances in methods for detection of anaerobic ammonium oxidizing (anammox) bacteria

Anaerobic ammonium oxidation (anammox), the biochemical process oxidizing ammonium into dinitrogen gas using nitrite as an electron acceptor, has only been recognized for its significant role in the global nitrogen cycle not long ago, and its ubiquitous distribution in a wide range of environments has changed our knowledge about the contributors to the global nitrogen cycle. Currently, several groups of methods are used in detection of anammox bacteria based on their physiological and biochemical characteristics, cellular chemical composition, and both 16S rRNA gene and selective functional genes as biomarkers, including hydrazine oxidoreductase and nitrite reductase encoding genes hzo and nirS, respectively. Results from these methods coupling with advances in quantitative PCR, reverse transcription of mRNA genes and stable isotope labeling have improved our understanding on the distribution, diversity, and activity of anammox bacteria in different environments both natural and engineered ones. In this review, we summarize these methods used in detection of anammox bacteria from various environments, highlight the strengths and weakness of these methods, and also discuss the new development potentials on the existing and new techniques in the future.Electronic supplementary materialThe online version of this article (doi:10.1007/s00253-011-3230-6) contains supplementary material, which is available to authorized users.

Advances in detection methods for EGFR gene mutation of lung cancer.

【中图分类号】 R734.2 DOI:10.3779/j.issn.1009-3419.2008.03.006 Advances in detection methods for EGFR gene mutation of lung cancer FENG Shuidong, TAN Hongzhuan Department of Epidemiology & Statistic, School of Public Health, Central South University, Changsha, Hunan 410008, China; Department of Epidemiology, School of Public Health, University of South China, Hengyang, Hunan 421001, China Corresponding author: TAN Hongzhuan, E-mail: tanhz99@QQ.com

Yessotoxins, a Group of Marine Polyether Toxins: an Overview

Yessotoxin (YTX) is a marine polyether toxin that was first isolated in 1986 from the scallop Patinopecten yessoensis. Subsequently, it was reported that YTX is produced by the dinoflagellates Protoceratium reticulatum, Lingulodinium polyedrum and Gonyaulax spinifera. YTXs have been associated with diarrhetic shellfish poisoning (DSP) because they are often simultaneously extracted with DSP toxins, and give positive results when tested in the conventional mouse bioassay for DSP toxins. However, recent evidence suggests that YTXs should be excluded from the DSP toxins group, because unlike okadaic acid (OA) and dinophyisistoxin-1 (DTX-1), YTXs do not cause either diarrhea or inhibition of protein phosphatases. In spite of the increasing number of molecular studies focused on the toxicity of YTX, the precise mechanism of action is currently unknown. Since the discovery of YTX, almost forty new analogues isolated from both mussels and dinoflagellates have been characterized by NMR or LC-MS/MS techniques. These studies indicate a wide variability in the profile and the relative abundance of YTXs in both, bivalves and dinoflagellates. This review covers current knowledge on the origin, producer organisms and vectors, chemical structures, metabolism, biosynthetic origin, toxicological properties, potential risks to human health and advances in detection methods of YTXs.

Yessotoxins, a Group of Marine Polyether Toxins: an Overview

Yessotoxin (YTX) is a marine polyether toxin that was first isolated in 1986 from the scallop Patinopecten yessoensis. Subsequently, it was reported that YTX is produced by the dinoflagellates Protoceratium reticulatum, Lingulodinium polyedrum and Gonyaulax spinifera. YTXs have been associated with diarrhetic shellfish poisoning (DSP) because they are often simultaneously extracted with DSP toxins, and give positive results when tested in the conventional mouse bioassay for DSP toxins. However, recent evidence suggests that YTXs should be excluded from the DSP toxins group, because unlike okadaic acid (OA) and dinophyisistoxin-1 (DTX-1), YTXs do not cause either diarrhea or inhibition of protein phosphatases . In spite of the increasing number of molecular studies focused on the toxicity of YTX, the precise mechanism of action is currently unknown. Since the discovery of YTX, almost forty new analogues isolated from both mussels and dinoflagellates have been characterized by NMR or LC-MS/MS techniques. These studies indicate a wide variability in the profile and the relative abundance of YTXs in both, bivalves and dinoflagellates. This review covers current knowledge on the origin, producer organisms and vectors, chemical structures, metabolism, biosynthetic origin, toxicological properties, potential risks to human health and advances in detection methods of YTXs.

Optical microarray biosensing techniques

AbstractMicroarrays provide a powerful analytical tool for the simultaneous analyses of thousands of parameters, be they DNA or proteins, in a single experiment. However, a number of challenges continue to hinder the widespread application of microarray assays for analytical and diagnostic purposes. Advances in detection methods can help overcome some of these challenges by improving sensitivity and reliability in signal detection and by enabling real‐time detection of binding events. Thus, the aim of this review is to highlight the most promising optical microarray biosensing techniques. The principles of techniques making use of labels, including scanner type, total internal reflection type, fiber‐optics‐based, and SPR‐enhanced fluorescence, are described, along with a brief summary of labeling strategies. State of the art label‐free techniques, including imaging SPR and imaging ellipsometry, are also reviewed. Examples of microarray‐based assays using each technique are given to illustrate both their usefulness and their limits of detection. Furthermore, the most competitive commercial microarray systems are presented and compared with one another in the context of their detection system. Finally, a discussion of the remaining challenges as well as trends and future applications of microarrays are presented in the context of optical sensing. Copyright © 2006 John Wiley & Sons, Ltd.

Focus Issue: Measurement on a Small Scale

This week's issues of Science and Science's STKE focus on how instrumentation is advancing investigation of biological questions. Science highlights how advances in detection methods are revealing the chemical aspects of biology, and STKE addresses techniques for single-molecule tracking and approaches to better understanding the interaction of cells with nanoparticles.

Role of angiogenesis in bladder response to partial outlet obstruction

Benign prostatic hyperplasia (BPH) is a disease that has its etiology in the abnormal growth of the adult human prostate gland that accompanies the aging process in men. The symptomatic presentation of this disease, however, is related largely to degenerative changes in the bladder that occur as a result of the increasing urethral resistance and partial bladder outlet obstruction (PBOO) caused by the growing prostate gland. BPH is characterized by bladder hypertrophy, significant decreases in urinary flow and compliance, presence of residual urine after voiding, voiding urgency and incontinence (). Obstructed bladder dysfunction secondary to BPH is a slow, progressive disease that is so strongly associated with human aging that it is an expected occurrence of the male aging process. Although the symptoms of BPH are usually not life threatening, they effect an extremely negative quality of life for men who suffer from them. However, many men delay seeking medical treatment for early BPH since bladder function can remain relatively normal as the hypertrophying bladder initially compensates for the progressive increase in urethral resistance caused by prostatic obstruction. The limited changes in micturition pressure and flow characteristics that occur during compensated function are not usually disabling enough to motivate seeking medical attention, which, often, is not sought until the symptoms become typical of advanced disease. Recent advances in detection methods enable identification of patients with significant BPH during compensation before the bladder becomes dysfunctional (decompensated). A more complete understanding of the disease processes that underlie the loss of bladder function associated with BPH might enable the development of treatments that better protect these early-stage BPH patients from the more debilitating aspects of the disease. This review updates the understanding of obstructive bladder dysfunction via the use of animal models.

Advances in detection methods for fungal and algal toxins

Natural ToxinsVolume 7, Issue 6 p. 343-345 Editorial Advances in detection methods for fungal and algal toxins† Frances M. Van Dolah, Corresponding Author Frances M. Van Dolah Conference Organizer NOAA/National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research, Charleston, South Carolina, USANOAA/National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research, Charleston, South Carolina, USASearch for more papers by this authorJohn L. Richard, John L. Richard Conference Organizer Romer Laboratories, Inc., Union, Missouri, USASearch for more papers by this author Frances M. Van Dolah, Corresponding Author Frances M. Van Dolah Conference Organizer NOAA/National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research, Charleston, South Carolina, USANOAA/National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research, Charleston, South Carolina, USASearch for more papers by this authorJohn L. Richard, John L. Richard Conference Organizer Romer Laboratories, Inc., Union, Missouri, USASearch for more papers by this author First published: 13 December 2000 https://doi.org/10.1002/1522-7189(199911/12)7:6<343::AID-NT88>3.0.CO;2-%23Citations: 4 † This article is a US Government Work and is in the public domain in the USA. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume7, Issue6November/December 1999Pages 343-345 RelatedInformation

Advances in detection methods for fungal and algal toxins.

Advances in detection methods for fungal and algal toxins.

Advances in detection methods for fungal and algal toxins

Advances in detection methods for fungal and algal toxins

The Epidemiologic Necropsy

To the Editor.— The suggestion in the article by McFarlane et al 1 that the increased occurrence of lung cancer in the United States during the past 30 years is due to improved diagnosis of disease is not supported by the data presented and is based on faulty logic. This article confirms what numerous other published studies have shown previously: many cancers go undetected. While the existence of an undetected reservoir leaves open the possibility that changes in the occurrence rates of a given cancer site could be due to improved detection methods, this is not likely to be the case for lung cancer for the following reasons. Technological advances in the detection of primary lung cancer have not been as extensive as purported in the article, and none have been widely applied in screening the population. Certainly, advances in detection methods for cancers such as those of the colon

Developments in detection methods for ion chromatography

Recent advances in detection methods for ion chromatography are reviewed, with particular emphasis on conductimetric, amperometric, potentiometric and indirect UV absorption methods. It is shown that a wide variety of detection methods now exists and this has decreased the dependence of ion chromatography on conductivity detection.

An overview of infectious agents of salpingitis, their biology, and recent advances in methods of detection

It was only in the decade of the 1970s that more extensive research into the etiology of acute salpingitis (pelvic inflammatory disease) was performed. Recently the development of new laboratory diagnostic methods and the detection and taxonomic differentiation of new organisms such as strictly anerobic bacteria chlamydiae and microplasms have contributed to an understanding of the etiology of acute salpingitis (AS). In this discussion AS and pelvic inflammatory disease (PID) are used synonymously. In reviewing infectious agents of salpingitis their biology and recent advances in methods of detection attention is directed to the following: 1) nontuberculous salpingitis (Neisseria gonorrhea anerobic infections mycoplasma hominis and Ureaplasma urealyticum Chlamydia trachomatis Chlamydial perihepatitis in acute salpingitis and miscellaneous and uncommon etiologic agents); 2) tuberculous salpingitis; 3) obtaining specimens in AS (lower genital tract uterine cavity and cul-de-sac and fallopian tubes); and 4) recent advances in laboratory diagnostic methods (tests for tubal isoamylases Neisseria gonorrhea anerobic bacteria mycoplasma hominis and Ureaplasma urealyticum Chlamydia trachomatis and mycobacteria. A common condition AS is on the increase in many countries as exemplified by studies from Lund Sweden. This increase in the incidence of PID appears to be associated with the pandemic situation of gonorrhea and other sexually transmitted diseases that has prevailed over the last 20 years. Most cases of AS are the result of an infection ascending from the cervix and in a large percentage of all women who develop AS the cervix is colonized by organisms known to be spread by sexual intercourse.