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Primary Screening (primary + screening)
Terms modified by Primary Screening Selected AbstractsOverexpression of cathepsin,B in gastric cancer identified by proteome analysisPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 6 2005Matthias P. A. Ebert Abstract We aimed to validate an analytical approach based on proteomics on gastric cancer specimens for the identification of new putative diagnostic or prognostic markers. Primary screening was performed on gastrectomy specimens obtained from ten consecutive patients with gastric cancer. Gastric epithelial cells were obtained with an epithelial cell enrichment technique, homogenized and then separated by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). The differential protein expression pattern was verified stepwise by Western blotting and immunohistochemistry on samples from 28 and 46,cancer patients, respectively. The putative clinical applicability and prognostic use were tested by an enzyme-linked immunoabsorbent assay on serum samples obtained from 149,cancer patients. One hundred-ninety-one differentially expressed protein spots were found by 2-D PAGE and identified by mass spectrometry, including cathepsin,B, which was over-expressed in six (60%) patients. Western blotting confirmed that the active form of cathepsin,B is over-expressed, while immunohistochemistry showed strong cytoplasmic staining in cancer tissues of 45 (98%) patients. The serum level of cathepsin,B was increased in patients with gastric cancer compared to healthy controls (P,=,0.0026) and correlated with T-category and the presence of distant metastases (P,<,0.05). Serum levels above 129,pmol·L,1 were associated with a reduced survival rate (P,=,0.0297). Proteome analysis is a valuable tool for the identification of prognostic markers in gastric cancer: Increased cathepsin,B serum levels are associated with advanced tumor stages and progressive disease, which enables the classification of some gastric cancer patients into a subgroup that should undergo aggressive therapy. [source] Cervical screening policies 2008 and beyondCYTOPATHOLOGY, Issue 2007R. Winder There are many developments in cytology and in the NHS that will impact on the NHS Cervical Screening Programme over the next few years. In the short term HPV is a major issue, whether triage, primary screening or vaccination with further evidence coming forward from NHS early implementers and from research trials. Cytology automation is also already being trialled for the UK. So far as NHS developments go, we already have the two Carter reports, one on pathology modernisation and one on commissioning are both likely to impact on our service, as is the forthcoming Cancer Reform Strategy which should be out in a few months time. This will set out a blue print for cancer services in 2012, by which time the cervical screening programme could have a very different shape. [source] Rapid (partial) prescreening of cervical smears: the quality control method of choice?CYTOPATHOLOGY, Issue 4 2002D. BROOKE Rapid rescreening of all negative and inadequate smears is the quality control method of choice in the UK. The sensitivity of primary screening of laboratory and individual screeners are major indicators of screening quality and are dependent on the number of false negative smears found by rapid screening for their calculation. High sensitivity may indicate good quality primary screening or poor quality rapid review. Quantifiably high quality rapid rescreening is essential if these sensitivity figures are to be meaningful. A 12-month study was undertaken in routine practice using the prescreening mode to ascertain the sensitivity of rapid (partial) screening in our department . The final results of smears were compared with those of rapid prescreening. The calculated sensitivity ranged from 92,54% for high-grade abnormalities and 75,33% for all grades, revealing a wide range of performance between individual prescreeners. Rapid prescreening can identify individuals best suited to rapid screening in routine practice. By using these prescreeners only, the sensitivity of cervical screening could be raised. Rapid (partial) prescreening should be considered as the quality control method of choice. [source] A plate assay for simultaneous screening of polysaccharide- and protein-degrading micro-organismsLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2005L.N. Ten Abstract Aims:, To develop a plate assay for simultaneous screening of polysaccharide-degrading and protein-degrading micro-organisms. Methods and Results:, A plate assay, based on the visible solubilization of small substrate particles and the formation of haloes on Petri dishes, containing a mixture of diversely coloured insoluble polysaccharides and dye-labelled collagen as chromogenic substrates, was developed. This method was successfully applied for isolating the diverse polysaccharide- and/or protein-degrading bacteria from soil and sludge samples. Selected strains were identified using 16S rDNA partial sequencing; most of them belong to the genera Bacillus, Cellulomonas and Cellulosimicrobium. Conclusions:, This novel approach provides unique and valuable information for direct primary screening when the target of selection is micro-organisms exhibiting protein-degrading activity, polysaccharide-degrading activity or a specific combination of them. Significance and Impact of the Study:, This plate assay is convenient and easy to perform, rapid, and more adaptable for screening of a large number of samples, compared with other existing methods in the literature. [source] The clinical relevance of human papillomavirus testing: relationship between analytical and clinical sensitivityTHE JOURNAL OF PATHOLOGY, Issue 1 2003Peter JF Snijders Abstract Given the fact that infection with high-risk human papillomavirus (HPV) is causally involved in cervical cancer, addition of high-risk HPV testing to a cervical smear may improve the efficacy of cervical cancer screening programmes, the triage of women with equivocal or borderline Pap smears, and the monitoring of women who have been treated for cervical intraepithelial neoplasia grade 3 (CIN 3). Compared to a cervical smear HPV tests revealed a superior sensitivity (ie clinical sensitivity) for lesions , CIN 3, and a negative predictive value approaching 100%. However, a potential complication is the availability of several HPV testing methods, all displaying a different sensitivity and specificity to detect HPV-positive women (ie analytical sensitivity and specificity). There is now compelling evidence that the clinical sensitivity and specificity of HPV tests are not simply synonymous to their analytical sensitivity and specificity, respectively. In fact, a distinction between so-called clinically relevant and irrelevant high-risk HPV infections should be made when considering HPV tests for primary screening, triage policies, or post-treatment monitoring. Here, we discuss the potential importance of HPV load in the context of currently widely applied HPV detection methods, to distinguish clinically relevant from irrelevant HPV infections. From this it can be concluded that it is of utmost importance to define criteria, involving viral load threshold and the type of HPV detection method that should be fulfilled by an HPV test before implementation of such a test in clinical practice and population-based cervical cancer screening programmes. Copyright © 2003 John Wiley & Sons, Ltd. [source] "Enzyme Test Bench," a high-throughput enzyme characterization technique including the long-term stabilityBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2009Kirill Rachinskiy Abstract A new high throughput technique for enzyme characterization with specific attention to the long term stability, called "Enzyme Test Bench," is presented. The concept of the Enzyme Test Bench consists of short term enzyme tests in 96-well microtiter plates under partly extreme conditions to predict the enzyme long term stability under moderate conditions. The technique is based on the mathematical modeling of temperature dependent enzyme activation and deactivation. Adapting the temperature profiles in sequential experiments by optimal non-linear experimental design, the long term deactivation effects can be purposefully accelerated and detected within hours. During the experiment the enzyme activity is measured online to estimate the model parameters from the obtained data. Thus, the enzyme activity and long term stability can be calculated as a function of temperature. The engineered instrumentation provides for simultaneous automated assaying by fluorescent measurements, mixing and homogenous temperature control in the range of 10,85,±,0.5°C. A universal fluorescent assay for online acquisition of ester hydrolysis reactions by pH-shift is developed and established. The developed instrumentation and assay are applied to characterize two esterases. The results of the characterization, carried out in microtiter plates applying short term experiments of hours, are in good agreement with the results of long term experiments at different temperatures in 1 L stirred tank reactors of a week. Thus, the new technique allows for both: the enzyme screening with regard to the long term stability and the choice of the optimal process temperature regarding such process parameters as turn over number, space time yield or optimal process duration. The comparison of the temperature dependent behavior of both characterized enzymes clearly demonstrates that the frequently applied estimation of long term stability at moderate temperatures by simple activity measurements after exposing the enzymes to elevated temperatures may lead to suboptimal enzyme selection. Thus, temperature dependent enzyme characterization is essential in primary screening to predict its long term behavior. Biotechnol. Bioeng. 2009;103: 305,322. © 2008 Wiley Periodicals, Inc. [source] Affinity Ligand Selection from a Library of Small Molecules: Assay Development, Screening, and ApplicationBIOTECHNOLOGY PROGRESS, Issue 1 2005Lakshmi D. Saraswat A facile and cost-effective process for screening synthetic libraries for an affinity ligand is described. A high throughput 96-well plate filtration method was designed to screen both discrete compounds and mixtures of compounds attached to a solid support. Human serum albumin (HSA) was used as a target protein to demonstrate the proof of concept. Detection and quantitation by fluorescence was accomplished with the use of fluorescamine to conjugate the protein in the filtrate. It is found that mixtures demonstrating low average binding reflect an overall lower hit rate of the components, whereas deconvolution of mixtures with high protein binding consistently provides a high hit rate. This differs from many of the previous experiences screening solid-phase mixtures in which high false positive rates are noted to occur. A total of 100K compounds were tested: 25K as discrete samples and 75K as mixtures. An overall hit rate of 8% was observed. Secondary screening of compounds measured specificity, recovery, and dynamic binding capacity. The effectiveness of the method is illustrated using an affinity column made with a representative lead compound. A similar purity was achieved in a single-step purification of HSA from serum as compared to that obtained by two steps of ion-exchange chromatography. The process for primary screening of a large number of compounds is simple, inexpensive, and applicable to any soluble target protein of known or unknown function from crude mixtures and may have additional utility as a generic chemical affinity tool for the functional characterization of novel proteins emerging from proteomics work. [source] | |||||||||||||