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Potential Usefulness (potential + usefulness)
Selected AbstractsOverexpression of CD49f in precursor B-cell acute lymphoblastic leukemia: Potential usefulness in minimal residual disease detectionCYTOMETRY, Issue 2 2009Joseph A. DiGiuseppe Abstract Background: The persistence of minimal residual disease (MRD) following therapy is an established prognostic factor in precursor B-cell acute lymphoblastic leukemia (pB-ALL). Detection of MRD in pB-ALL by flow cytometric immunophenotyping requires demonstration of abnormal antigen expression in leukemic B-cell precursors relative to that of normal B-cell precursors. The gene encoding CD49f (integrin ,-6) is one of several whose overexpression in pB-ALL at diagnosis has been associated with the subsequent detection of MRD. However, whether CD49f might be a useful reagent in the immunophenotypic detection of MRD in pB-ALL has not been evaluated. Methods: We evaluated CD49f expression by 4-color flow cytometry in normal B-cell precursors, and in a series of cases of pB-ALL, both at diagnosis and at intervals following the initiation of therapy. Results: In 10 control marrow samples, CD49f was undetectable or extremely dim in all but a minor subset of normal CD19+ B-lineage cells, whereas in 11 of 15 cases (73%) of pB-ALL, CD49f was moderate or bright at diagnosis, and persisted or became brighter after initiation of therapy. MRD detected using CD49f corresponded precisely with that obtained using a standard panel of antibodies, and permitted the detection of leukemic populations comprising as little as 0.02% of cells. Of the four pB-ALL cases in which CD49f was undetectable or dim at diagnosis, MRD was detected in two; in one of these, CD49f expression was substantially increased in the leukemic cells that persisted following initiation of therapy. Conclusions: CD49f is commonly overexpressed in p-B-ALL, and represents a potentially useful marker for the immunophenotypic detection of MRD. © 2008 Clinical Cytometry Society How to cite this article: DiGiuseppe JA, Fuller SG, Borowitz MJ. Overexpression of CD49f in precursor B-cell acute lymphoblastic leukemia: potential usefulness in minimal residual disease detection. Cytometry Part B 2008. [source] Zebrafish notch signalling pathway mutants exhibit trunk vessel patterning anomalies that are secondary to somite misregulationDEVELOPMENTAL DYNAMICS, Issue 10 2010Christina Therapontos Abstract The Notch signalling pathway mutants, after-eight (aei), beamter (bea), and deadly-seven (des) have previously been used to study somitogenesis and neurogenesis. Notch signalling has also been shown to have roles in vascular development. However, vascular development in each of these three Notch mutants has not been described, and so their potential usefulness for further understanding the role of Notch signalling in angiogenesis is unknown. Here we demonstrate each of the mutants also exhibit vascular defects in inter-somitic vessel (ISV) positioning and patterning. Ectopic filopodia were also observed on the ISVs of the mutants. Ectopic filopodia are not due to loss of dll4. Somite expression of known vascular guidance cues, efnb2, sema3a2, and plexinD1 are disrupted, suggesting that the ISV vascular phenotype is due to disruption of these cues. Developmental Dynamics 239:2761,2768, 2010. © 2010 Wiley-Liss, Inc. [source] The accuracy of cystatin C and commonly used creatinine-based methods for detecting moderate and mild chronic kidney disease in diabetesDIABETIC MEDICINE, Issue 4 2007R. J. MacIsaac Abstract Background, The accuracy of measuring serum cystatin C levels for detecting various stages of chronic kidney disease (CKD) in diabetes is still unclear. Methods In a cross-sectional study of 251 subjects, a reference glomerular filtration rate (GFR) was measured using 99cTc-DTPA plasma clearance (iGFR). Multivariate analysis was used to identify independent clinical and biochemical associations with serum cystatin C and iGFR levels. The diagnostic accuracy of cystatin C and commonly used creatinine-based methods of measuring renal function (serum creatinine, the MDRD four-variable and Cockcroft,Gault formulae) for detecting mild and moderate CKD was also compared. Results, In the entire study population the same five variables, age, urinary albumin excretion rates, haemoglobin, history of macrovascular disease and triglyceride levels were independently associated with both cystatin C and iGFR levels. A serum cystatin C level cut-off > 82.1 nmol/l (1.10 mg/l) had the best test characteristics as a screening tool for detecting moderate CKD (< 60 ml/min per 1.73 m2) when compared with creatinine-based methods. At the upper threshold for mild CKD (< 90 ml/min per 1.73 m2), cystatin C also had greater diagnostic accuracy than creatinine, but had similar diagnostic accuracy when compared with creatinine-based formulae for predicting renal function. Conclusions, This study suggests that the clinical and biochemical parameters associated with serum cystatin C levels are closely linked to those associated with GFR and highlights the potential usefulness of screening for moderate or mild CKD in subjects with diabetes by simply measuring serum cystatin C levels. [source] Macro,micro analysis method for wave propagation in stochastic mediaEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 4 2006T. Ichimura Abstract This paper presents a new analysis method, called macro,micro analysis method (MMAM) for numerical simulation of wave propagation in stochastic media, which could be used to predict distribution of earthquake strong motion with high accuracy and spatial resolution. This MMAM takes advantage of the bounding medium theory (BMT) and the singular perturbation expansion (SPE). BMT can resolve uncertainty of soil and crust structures by obtaining optimistic and pessimistic estimates of expected strong motion distribution. SPE leads to efficient multi-scale analysis for reducing a huge amount of computation. The MMAM solution is given as the sum of waves of low resolution covering a whole city and waves of high resolution for each city portion. This paper presents BMT and SPE along with the formulation of MMAM for wave propagation in three-dimensional elastic media. Application examples are presented to verify the validity of the MMAM and demonstrate potential usefulness of this approach. In a companion paper (Earthquake Engng. Struct. Dyn., this issue) application examples of earthquake strong motion prediction are also presented. Copyright © 2005 John Wiley & Sons, Ltd. [source] Plasticity of hair follicle dermal cells in wound healing and inductionEXPERIMENTAL DERMATOLOGY, Issue 2 2003A. Gharzi Abstract: The capacity of adult hair follicle dermal cells to participate in new follicle induction and regeneration, and to elicit responses from diverse epithelial partners, demonstrates a level of developmental promiscuity and influence far exceeding that of interfollicular fibroblasts. We have recently suggested that adult follicle dermal cells have extensive stem or progenitor cell activities, including an important role in skin dermal wound healing. Given that up to now tissue engineered skin equivalents have several deficiencies, including the absence of hair follicles, we investigated the capacity of follicle dermal cells to be incorporated into skin wounds; to form hair follicles in wound environments; and to create a hair follicle-derived skin equivalent. In our study, we implanted rat follicle dermal cells labelled with a vital dye into ear and body skin wounds. We found that they were incorporated into the new dermis in a manner similar to skin fibroblasts, but that lower follicle dermal sheath also assimilated into hair follicles. Using different combinations of follicle dermal cells and outer root sheath epithelial cells in punch biopsy wounds, we showed that new hair follicles were formed only with the inclusion of intact dermal papillae. Finally by combining follicle dermal sheath and outer root sheath cells in organotypic chambers, we created a skin equivalent with characteristic dermal and epidermal architecture and a normal basement membrane , the first skin to be produced entirely from hair follicle cells. These data support the hypothesis that follicle dermal cells may be important in wound healing and demonstrate their potential usefulness in human skin equivalents and skin substitutes. While we have made progress towards producing skin equivalents that contain follicles, we suggest that the failure of cultured dermal papilla cells to induce follicle formation in wounds illustrates the complex role the follicle dermis may play in skin. We believe that it demonstrates a genuine dichotomy of activity for follicle cells within skin. [source] An early warning system for financial crisis using a stock market instability indexEXPERT SYSTEMS, Issue 3 2009Dong Ha Kim Abstract: This paper proposes to utilize a stock market instability index (SMII) to develop an early warning system for financial crisis. The system focuses on measuring the differences between the current market conditions and the conditions of the past when the market was stable. Technically the system evaluates the current time series against the past stable time series modelled by an asymptotic stationary autoregressive model via artificial neural networks. Advantageously accessible to extensive resources, the system turns out better results than the conventional system which detects similarities between the conditions of the current market and the conditions of previous markets that were in crisis. Therefore, it should be considered as a more advanced tool to prevent financial crises than the conventional one. As an empirical example, an SMII for the Korean stock market is developed in order to demonstrate its potential usefulness as an early warning system. [source] Simulations to Verify Horizontal Flow Measurements from a Borehole FlowmeterGROUND WATER, Issue 3 2006Scott C James This paper reports on experiments and simulations of subsurface flow from a slotted acrylic tube deployed in a sand-tank flow chamber for two different purposes. In the first instance, the slotted tube is used to represent a single fracture intersected by an uncased well. In the second instance, the slotted tube is used to represent a multislot well screen within a porous medium. In both cases, the scanning colloidal borescope flowmeter (SCBFM) measures ground water velocity within the well by imaging colloids traveling through a well to measure their speed and direction. Measurements are compared against model simulations. For the case of a slotted tube representing a single fracture, SCBFM and model results agree with respect to the flow direction and to within a factor of 1.5 for the speed near the well's center. Model and experimental agreement lend confidence that for an uncased well drilled in a fractured-rock medium, a calibrated SCBFM could be used to identify and quantify flowing features. Next, the SCBFM was deployed in a four-column multislotted casing with slots aligned with the flow direction. Another numerical model was developed to estimate the flow field within this well screen to evaluate the potential usefulness of employing the SCBFM in a screened well to estimate flow speed and direction in the surrounding porous medium. Results indicate that if the slots are not aligned with the flow, the SCBFM may only provide order-of-magnitude speed measurements and direction measurements with an uncertainty of approximately ±25°. [source] ABCG2 (BCRP) expression in normal and malignant hematopoietic cellsHEMATOLOGICAL ONCOLOGY, Issue 3 2003Brian L. Abbott Abstract ABCG2 (BCRP) is a member of the ATP-binding cassette (ABC) family of cell surface transport proteins. ABCG2 expression occurs in a variety of normal tissues, and is relatively limited to primitive stem cells. ABCG2 expression is associated with the side population (SP) phenotype of Hoechst 33342 efflux. The substrate profile of ABCG2 includes the antineoplastic drugs primarily targeting topoisomerases, including anthracyclines and camptothecins. More recently, pheophorbide, a chlorophyll-breakdown product, and protoporhyrin IX have been described as ABCG2 substrates, perhaps indicating a physiologic role of cytoprotection of primitive cells. Also, mice lacking ABCG2 expression have no intrinsic stem cell defects, although there is a remarkable increase in toxicity with antineoplastic drugs that are ABCG2 substrates, and also a photosensitivity resembling protoporphyria. Like other members of the ABC family, such as MDR1 and MRP1, ABCG2 is expressed in a variety of malignancies. Despite numerous reports of ABCG2 expression in AML, there is little evidence that ABCG2 expression is correlated with an adverse clinical outcome. This review will focus on the potential usefulness of ABCG2 as a marker primitive stem cells and possible physiologic roles of ABCG2 in protection of primitive stem cell populations, and potential methods of overcoming ABCG2-associated drug resistance in anticancer therapy. Copyright © 2003 John Wiley & Sons, Ltd. [source] Immunohistochemistry in melanocytic proliferative lesionsHISTOPATHOLOGY, Issue 6 2004N J W De Wit Melanoma incidence is rising worldwide. Early diagnosis is very important, as the most effective treatment for melanoma still consists of excision of the tumour before onset of the metastatic growth phase. Immunohistochemistry is a valuable tool for (dermato)pathologists to aid establishing diagnosis. Melanoma markers can be classified into two main categories: melanocytic differentiation markers and melanoma progression markers. Melanocytic differentiation markers are mostly used to distinguish poorly differentiated melanomas from non-melanocytic tumours and for staging of melanocytic proliferative lesions. Melanoma progression markers are most suitable to determine the level of malignancy and/or aggressiveness of tumour cells. This review describes the classification of melanoma markers, including commonly used and recently identified antigens with potential marker function. We characterize their expression profile in melanocytic proliferative lesions and their potential usefulness for diagnosis, prognosis, microstaging, immunotherapeutic purposes and evaluation of therapies. [source] Location of a missing object and detection of its absence by infants: Contribution of an eye-tracking system to the understanding of infants' strategiesINFANT AND CHILD DEVELOPMENT, Issue 4 2004Roger Lécuyer Abstract Previous research has demonstrated infants' capacity to discriminate between situations in which all the objects successively hidden behind a screen are present, or not, after the removal of the screen. Two types of interpretation have been proposed: counting capacity or object memorization capacity. In the usual paradigm, the missing object in the impossible event is usually the last object which is placed behind the screen. Following this, a third interpretation can be offered: infants' exploration is first directed to this object's location, and its presence or absence is noticed. Two experiments using Wynn's (Nature 1992; 358:749) paradigm were performed to test the third hypothesis. The first experiment involved four objects (teddy bears) placed in four squares. Infants looked longer at the impossible event (3 objects, the last one missing) than at the possible event (4 objects) when the impossible event was presented first. No difference in looking duration was observed for the opposite order. In the second experiment, the four objects were disposed in a line and an eye-tracking system was used. No difference in the number of looks was observed between the impossible event (3 objects, the second one missing) and the possible event (4 objects). Therefore, it appears that at least in this complex situation (4 objects used instead of 2 usually), the location of the missing object is a key factor for event discrimination. Eye-tracking also indicated in the second experiment that infants looked less at the second location during an impossible event (object missing) than during the possible event (object present), indicating that the impossibility of the event was not a determining factor for looking durations. Altogether, the data indicate the potential usefulness of eye-tracking analysis in this type of situation. Copyright © 2004 John Wiley & Sons, Ltd. [source] Internet-based information systems use in organizations: an information studies perspectiveINFORMATION SYSTEMS JOURNAL, Issue 2 2003Brian Detlor Abstract. This case study investigates various ways in which different internet-based information systems (IS) are used by organizational participants. Borrowing theoretical insights on information behaviour accumulated over 50 years of information studies research, a conceptual framework is presented to help understand and assess the social and organizational impacts of internet-based IS. The framework describes the use of internet-based IS as a dynamic cycle of information needs,seeking,use activity situated in the context of a firm's information environment. Research questions pertain to the process of how individuals in organizations seek and use information from internet-based IS to satisfy information needs. In terms of information needs, this involves understanding the problem situations that lead participants to use internet-based IS, as well as the characteristics of those problems beyond subject matter. With respect to information seeking, this involves analysing how information from internet-based systems is displayed and formatted to signal their potential usefulness. In terms of information use, this involves how information obtained from internet-based systems is used in practice to resolve or redefine problems. Both quantitative and qualitative research methods are used. Data collection involves web tracking to identify significant episodes of internet-based IS activity, as well as one-on-one interviews to explore the context behind these episodes. Results suggest that it is possible and valuable to identify scenarios of internet-based IS use dominant in an organizational work setting. Doing so can help to identify ways to improve the situated use of internet-based IS that ameliorate the information needs,seeking,use cycle in firms. [source] Using molecular and quantitative variation for assessing genetic impacts on Nucella lapillus populations after local extinction and recolonizationINTEGRATIVE ZOOLOGY (ELECTRONIC), Issue 2 2006Isabelle Colson Abstract The dogwhelk Nucella lapillus is a predatory marine gastropod living on rocky shores in the North Atlantic. As with many other gastropod species, Nucella was affected by tributyltin (TBT) pollution during the 1970s and 1980s, and local populations underwent extinction. After a partial ban on TBT in the UK in 1987, vacant sites have been recolonized. Levels of genetic diversity and quantitative genetic variation in shell form were compared between recolonized sites and sites that showed continuous population at three localities across the British Isles. Overall, estimates of genetic diversity were only slightly lower in recolonized populations, suggesting that populations have recovered from previous impacts due to the relatively high levels of migration from non-impacted sites. Molecular and quantitative analyses are broadly concordant and a positive correlation was observed (although not statistically significant) between molecular and quantitative estimates of genetic diversity, indicating the potential usefulness of quantitative methods to complement molecular population genetics analyses. [source] Does the Yield Spread Predict Recessions in the Euro Area?,INTERNATIONAL FINANCE, Issue 2 2005Fabio MonetaArticle first published online: 16 DEC 200 This paper studies the informational content of the slope of the yield curve as a predictor of recessions in the euro area and provides evidence of the potential usefulness of this indicator for monetary policy purposes. In particular, the historical predictive power of ten variations of yield spreads, for different segments of the yield curve, is tested using a probit model. The yield spread between the ten-year government bond rate and the three-month interbank rate outperforms all other spreads in predicting recessions in the euro area. The forecast accuracy of the spread between ten-year and three-month interest rates is also explored in an exercise of out-of-sample forecasting. This yield spread appears to contain information beyond that already available in the history of output, and to outperform other competitor indicators. [source] Flux and source term discretization in two-dimensional shallow water models with porosity on unstructured gridsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 3 2006Vincent Guinot Abstract Two-dimensional shallow water models with porosity appear as an interesting path for the large-scale modelling of floodplains with urbanized areas. The porosity accounts for the reduction in storage and in the exchange sections due to the presence of buildings and other structures in the floodplain. The introduction of a porosity into the two-dimensional shallow water equations leads to modified expressions for the fluxes and source terms. An extra source term appears in the momentum equation. This paper presents a discretization of the modified fluxes using a modified HLL Riemann solver on unstructured grids. The source term arising from the gradients in the topography and in the porosity is treated in an upwind fashion so as to enhance the stability of the solution. The Riemann solver is tested against new analytical solutions with variable porosity. A new formulation is proposed for the macroscopic head loss in urban areas. An application example is presented, where the large scale model with porosity is compared to a refined flow model containing obstacles that represent a schematic urban area. The quality of the results illustrates the potential usefulness of porosity-based shallow water models for large scale floodplain simulations. Copyright © 2005 John Wiley & Sons, Ltd. [source] Effects of Rare-Earth Dopants on the Ferroelectric and Pyroelectric Properties of Strontium Barium Niobate CeramicsINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 6 2009Yingbang Yao Effects of various rare-earth (RE) dopants (Y3+, La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tm3+, Dy3+, Er3+, and Yb3+) on the dielectric, ferroelectric, and pyroelectric properties of Sr0.5Ba0.5Nb2O6 (SBN50) ceramics were investigated. In the present studies, the doping concentrations of all the RE dopants were fixed at 1 mol%. Their potential usefulness in pyroelectric applications was discussed based on their measured pyroelectric detectivity figure of merit (FOM). On the basis of our studies, for RE dopants with atomic numbers smaller than Nd, their dielectric constants were greatly increased, while for RE dopants with atomic numbers larger than Sm, their dielectric constants as well as dielectric losses became smaller. Among various dopants, Eu-doped SBN showed the most improved ferroelectric properties. Its remnant polarization (Pr) was increased to 4.86 ,C/cm2 as compared with 3.23 ,C/cm2 obtained in undoped SBN50. On the other hand, Gd-doped SBN exhibited the largest pyroelectric coefficient of 168 ,C/m2 K, which was over three times of that of the undoped sample (49 ,C/m2 K). The work shows that Gd-doped SBN exhibits the greatest potential for pyro-applications because it bears the largest FOM of 0.45 × 10,5 Pa,0.5 [Correction: After online publication on 11/05/2008, an error was found in this article. The original value, 1.35×10,5 Pa,0.5, was incorrect. The data has been replaced with the correct value.]. [source] Citicoline affects appetite and cortico-limbic responses to images of high-calorie foodsINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 1 2010William D.S. Killgore PhD Abstract Objective: Cytidine-5,-diphosphocholine (citicoline) has a variety of cognitive enhancing, neuroprotective, and neuroregenerative properties. In cocaine-addicted individuals, citicoline has been shown to increase brain dopamine levels and reduce cravings. The effects of this compound on appetite, food cravings, and brain responses to food are unknown. Method: We compared the effects of treatment with Cognizin® citicoline (500 mg/day versus 2,000 mg/day) for 6 weeks on changes in appetite ratings, weight, and cortico-limbic responses to images of high-calorie foods using functional magnetic resonance imaging (fMRI). Results: After 6 weeks, there was no significant change in weight status, although significant declines in appetite ratings were observed for the 2,000 mg/day group. The higher dose group also showed significant increases in functional brain responses to food stimuli within the amygdala, insula, and lateral orbitofrontal cortex. Increased activation in these regions correlated with declines in appetite ratings. Discussion: These preliminary findings suggest a potential usefulness of citicoline in modulating appetite, but further research is warranted. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010 [source] Toughness of Spider Silk at High and Low Temperatures,ADVANCED MATERIALS, Issue 1 2005Y. Yang The toughness of the major ampullate silk of spiders is shown to increase at low temperatures, unlike synthetic fibers. This temperature dependence of the mechanical properties of spider silk, together with other remarkable properties, demonstrates the potential usefulness of such a super-fiber in harsh environments. The Figure shows a single fiber of Nephila edulis spider silk fractured in liquid nitrogen. [source] Food security problems in sub-Saharan Africa: Operations Research as a tool of analysisINTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 2 2008Caspar Schweigman Abstract For many years, the author has been involved in teaching and research in the use of Operations Research as a tool of analysis to study food security problems in sub-Saharan Africa, in particular, grass root problems of poor farmers. The paper presents an introduction to the way Operations Research methods have been applied in case studies and research projects, and discusses in retrospect the author's views on the strengths and limitations of the application of Operations Research. The paper has in particular been written for people who are not familiar with applications of Operations Research in agriculture, and are interested to learn about its potential usefulness in practice. The retrospective part is largely based on food security studies in e.g. Tanzania, Burkina Faso, Bénin, Togo and Eritrea and on participation in several interdisciplinary research programmes in Africa. [source] Structural Diversification of Macrolactones by Substrate-Flexible Cytochrome P450 MonooxygenasesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2005Kil Lee Abstract The substrate flexibilities of several cytochrome P450 monooxygenases involved in macrolide biosynthesis were investigated to test their potential for the generation of novel macrolides. PikC hydroxylase in the pikromycin producer Streptomyces venezuelae accepted oleandomycin as an alternative substrate and introduced a hydroxy group at the C-4 position, which is different from the intrinsic C-12 hydroxylation position in the natural substrate. This is the first report of C-4 hydroxylation activity of cytochrome P450 monooxygenase involved in the biosynthesis of 14-membered macrolides. EryF hydroxylase from the erythromycin biosynthetic pathway of Saccharopolyspora erythraea and OleP oxidase from the oleandomycin biosynthetic pathway of Streptomyces antibioticus also showed a certain degree of plasticity towards alternative substrates. In particular, EryF and OleP were found to oxidize a 12-membered macrolactone as an alternative substrate. These results demonstrate the potential usefulness of these enzymes to diversify macrolactones by post-PKS oxidations. [source] Piecewise linear relaxation of bilinear programs using bivariate partitioningAICHE JOURNAL, Issue 7 2010M. M. Faruque Hasan Abstract Several operational and synthesis problems of practical interest involve bilinear terms. Commercial global solvers such as BARON appear ineffective at solving some of these problems. Although recent literature has shown the potential of piecewise linear relaxation via ab initio partitioning of variables for such problems, several issues such as how many and which variables to partition, which partitioning scheme(s) and relaxation model(s) to use, placement of grid points, etc., need detailed investigation. To this end, we present a detailed numerical comparison of univariate and bivariate partitioning schemes. We compare several models for the two schemes based on different formulations such as incremental cost (IC), convex combination (CC), and special ordered sets (SOS). Our evaluation using four process synthesis problems shows a formulation using SOS1 variables to perform the best for both partitioning schemes. It also points to the potential usefulness of a 2-segment bivariate partitioning scheme for the global optimization of bilinear programs. We also prove some simple results on the number and selection of partitioned variables and the advantage of uniform placement of grid points (identical segment lengths for partitioning). © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Synthesis and biodistribution in mice of a new 99mTc nitrido complex for brain imagingJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 10 2004Junbo Zhang Abstract The bis(N -cyclopentyl dithiocarbamato) nitrido technetium-99m complex 99mTcN(CPEDTC)2 was synthesized by the reduction of 99mTcO into [99mTc,N]2+ with stannous chloride in the presence of succinic dihydrazide and propylenediamine tetraacetic acid, followed by the addition of sodium N -cyclopentyl dithiocarbamate monohydrate. The radiochemical purity (RCP) of the product was over 90% as measured by thin layer chromatography(TLC) and high performance liquid chromatography(HPLC). In vitro studies showed that the complex possessed good stability under physiological conditions. Its partition coefficient studies indicated it was a good lipophilic complex. The electrophoresis results showed the complex was neutral. The biodistribution results in mice indicated that 99mTcN(CPEDTC)2 was significantly retained into the brain. The brain uptake(ID%/g) was 3.58, 5.26, 3.73 and 2.72 and the brain/blood ratios were 0.79, 1.69, 1.59 and 1.58 at 5, 30, 60 and 90 min post-injection, respectively. These results suggested potential usefulness of the complex as a new brain perfusion imaging agent. Copyright © 2004 John Wiley & Sons, Ltd. [source] Equilibrium theory analysis of rectifying PSA for heavy component productionAICHE JOURNAL, Issue 8 2002Armin D. Ebner An isothermal equilibrium theory analysis, based on linear isotherms and a binary feed stream, was carried out to evaluate the feasibility of a rectifying PSA process for producing a pure heavy component at high recovery. Analytic expressions were derived to describe the performance of this process at the periodic state. The performance was also analyzed in terms of the different concentration and velocity profiles exhibited during various cycle steps that included the analysis of complex shock and simple wave interactions. Based on a parametric study, periodic behavior was established for a wide range of process conditions; and a design study with the PCB activated carbon,H2,CH4 system at 25°C further demonstrated the feasibility of a rectifying PSA cycle for producing a 100% CH4 stream from a dilute feed stream (y = 0.01) with a respectable recovery (80%), and reasonable process conditions. It also demonstrated the potential usefulness of an actual rectifying PSA process for bulk gas separation and purification. [source] Characterization of spreadability of nonaqueous ethylcellulose gel matrices using dynamic contact angleJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 8 2008Keat Theng Chow Abstract This study reports the characterization of spreadability of nonaqueous ethylcellulose (EC) gel matrices intended for topical drug delivery using a newly developed method based on dynamic contact angle. EC solutions were prepared using three grades of EC and propylene glycol dicaprylate/dicaprate. Dynamic contact angles of sessile drops of EC solutions on silicone elastomer were measured using a dynamic contact angle analyzer equipped with axisymmetric drop shape analysis-profile. Roughness of silicone elastomer, viscosity of EC solutions and compressibility of semisolid EC gels were determined by the atomic force microscope, cone-and-plate rheometer and tensile tester, respectively. The silicone elastomer employed as a substrate was demonstrated to have similar hydrophilic/lipophilic properties as the human skin. Spreadability of EC solutions was dependent on EC concentration, polymeric chain length and polydispersity. EC gel spreadability was governed by viscosity and the extent of gel-substrate interaction. From the apparent contact angle values, most EC gel formulations tested were found to be moderately spreadable. Linear correlation observed between spreading parameter and compressibility of EC gel verified the applicability of dynamic contact angle to characterize EC gel spreadability. Thus, the feasibility of employing dynamic contact angle as an alternative technique to measure gel spreadability was demonstrated. The spreadability demonstrated by EC gel would facilitate application on the skin indicating its potential usefulness as a topical dosage form. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97: 3467,3482, 2008 [source] The use of three different solid dispersion formulations,melt extrusion, film-coated beads, and a glass thermoplastic system,to improve the bioavailability of a novel microsomal triglyceride transfer protein inhibitorJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2004Geert Verreck Abstract A bioavailable formulation for a water-insoluble microsomal triglyceride transfer protein inhibitor, R103757, was developed using solid dispersion technology. The need for an advanced formulation was tested in the dog by assessing the oral bioavailability of three generic concepts: a tablet (crystalline drug), a capsule (film-coated beads), and an oral solution. These screening studies steered further development in the direction of a solid dispersion. Three solid dispersion platforms were assessed: melt extrusion, film-coated beads, and a glass thermoplastic system. Thermal and spectrophotometric analysis revealed that no crystalline drug was present in any of the formulations. The dissolution profiles of the three dispersion systems showed that release was improved compared with the unmanipulated drug. In addition, stability studies confirmed the physical and chemical integrity of the formulation. A human clinical trial was performed to assess the pharmacokinetics of the three amorphous dispersions. Plasma levels were obtained after single oral administration in both the fasting and fed state. The study indicated that all three approaches improved the bioavailability of R103757 with the glass thermoplastic system providing the best performance. These studies point to the potential usefulness of solid dispersion approaches and expand the possible number of ways to implement these methodologies. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:1217,1228, 2004 [source] Cytokines alter the expression and activity of the multidrug resistance transporters in human hepatoma cell lines; analysis using RT-PCR and cDNA microarraysJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 11 2003Gigi Lee Abstract Pro-inflammatory cytokines suppress the hepatic expression of the multidrug resistance transporters in rodents, indicating potential usefulness in chemotherapy. Our objective was to investigate their impact in human hepatoma cells. HuH 7 and HepG2 cells were treated with IL-1,, IL-6, or TNF-, for 0,72 h. Expression and activity of MDR1 and the MRP (MRP1, 2, 3, and 6) transporters were examined by RT-PCR, efflux assays, and microarrays. Significant reductions in the MDR1-mediated efflux of Rhodamine 123 and MDR1 mRNA levels were observed in HuH 7 cells treated with IL-6, TNF-,, or IL-1, and in TNF-,,treated HepG2 cells. However, cytokine-treated HuH7 cells also demonstrated 1.6- to 2.6-fold greater efflux of the MRP substrate, 5-carboxyfluorescein (5-CF) and higher MRP3 mRNA levels (p,<,0.05). IL-1, and IL-6 treatments increased MRP activity and MRP1 mRNA levels in HepG2 cells (p,<,0.05). Microarrays studies performed in IL-6 and TNF-,,treated HepG2 cells detected similar changes in the expression of the MDR1 and MRP transporters, but this did not reach significance. However, the microarrays confirmed cytokine-mediated induction of several acute phase proteins. Our data suggests that although cytokine-mediated suppression of PGP may alter drug resistance in malignant cells, these cytokines may also impose an induction in other multidrug resistance genes. © 2003 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 92:2152,2163, 2003 [source] Extracorporeal photochemotherapy in patients with cutaneous T-cell lymphoma: is clinical response predictable?JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 9 2006V Rao Abstract Background, Extracorporeal photochemotherapy (ECP) has been accepted as a standard therapy in cutaneous T-cell lymphomas (CTCL), a category of lymphomas mainly resistant to conventional therapies. Approximately one half of patients demonstrate a reduction in skin affliction by at least 50% within 12 months of therapy and are categorized as responders to ECP. Predictive criteria for selecting patients who will respond to ECP are lacking. Such criteria would however, be of great benefit. Objectives, This study compared T-cell clonality and serum levels of soluble interleukin-2 receptor (sIL-2R), lactate dehydrogenase (LD), neopterin, beta2-microglobulin (,2 -M) and granzyme B in CTCL patients in order to evaluate their potential usefulness as predictive markers. Patients/methods, Serum and T lymphocytes obtained from 16 patients with CTCL receiving ECP treatment were evaluated in an open retrospective study. Results, We found no evident correlation between detected T-cell clonality and response to ECP. The non-responding group had on average a higher level of serum sIL-2R. This difference was significant after 6 and 12 months of therapy, but not pretreatment. An individual reduction in serum sIL-2R, neopterin and ,2 -M during a 6-month course of ECP was well correlated to clinical remission. Conclusions, Seven out of 16 patients were classified as responders. Neither T-cell clonality nor any of the serum markers assessed pretreatment could reliably predict the response to ECP treatment. However, the individual relative changes in sIL-2R, neopterin and ,2 -M during 6 months of ECP treatment coherently displayed correlation to the clinical response, as assessed after 12 months of ECP treatment. [source] European Federation of Neurological Societies/Peripheral Nerve Society Guideline on the use of skin biopsy in the diagnosis of small fiber neuropathy.JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 2 2010Report of a joint task force of the European Federation of Neurological Societies, the Peripheral Nerve Society Revision of the guidelines on the use of skin biopsy in the diagnosis of peripheral neuropathy, published in 2005, has become appropriate due to publication of more relevant papers. Most of the new studies focused on small fiber neuropathy (SFN), a subtype of neuropathy for which the diagnosis was first developed through skin biopsy examination. This revision focuses on the use of this technique to diagnose SFN. Task force members searched the Medline database from 2005, the year of the publication of the first EFNS guideline, to June 30th, 2009. All pertinent papers were rated according to the EFNS and PNS guidance. After a consensus meeting, the task force members created a manuscript that was subsequently revised by two experts (JML and JVS) in the field of peripheral neuropathy and clinical neurophysiology, who were not previously involved in the use of skin biopsy. Distal leg skin biopsy with quantification of the linear density of intraepidermal nerve fibers (IENF), using generally agreed upon counting rules, is a reliable and efficient technique to assess the diagnosis of SFN (level A recommendation). Normative reference values are available for bright-field immunohistochemistry (level A recommendation) but not yet for confocal immunofluorescence or the blister technique. The morphometric analysis of IENF density, either performed with bright-field or immunofluorescence microscopy, should always refer to normative values matched for age (level A recommendation). Newly established laboratories should undergo adequate training in a well established skin biopsy laboratory and provide their own stratified age and gender-matched normative values, intra- and interobserver reliability, and interlaboratory agreement. Quality control of the procedure at all levels is mandatory (Good Practice Point). Procedures to quantify subepidermal nerve fibers and autonomic innervated structures, including erector pili muscles, and skin vessels are under development but need to be confirmed by further studies. Sweat gland innervation can be examined using an unbiased stereologic technique recently proposed (level B recommendation). A reduced IENF density is associated with the risk of developing neuropathic pain (level B recommendation), but it does not correlate with its intensity. Serial skin biopsies might be useful for detecting early changes of IENF density, which predict the progression of neuropathy, and to assess degeneration and regeneration of IENF (level C recommendation). However, further studies are warranted to confirm the potential usefulness of skin biopsy with measurement of IENF density as an outcome measure in clinical practice and research. Skin biopsy has not so far been useful for identifying the etiology of SFN. Finally, we emphasize that 3-mm skin biopsy at the ankle is a safe procedure based on the experience of 10 laboratories reporting absence of serious side effects in approximately 35,000 biopsies and a mere 0.19% incidence of non-serious side effects in about 15 years of practice (Good Practice Point). [source] Ego Identity Status as an Indicator of Peer Court EfficacyJUVENILE AND FAMILY COURT JOURNAL, Issue 3 2003RANDALL M. JONES ABSTRACT Peer courts are an alternative to juvenile court, intended to provide less stigmatizing and more individually responsive dispositions for first-time and early youthful offenders. This study examined the potential usefulness of assessing ego identity status for peer courts. Mailed surveys were sent to attendees of seven Utah peer courts who had their cases reviewed between August 1998 and January 1999. Thirty-seven percent (N = 120) responded. Chi Square analysis showed that ego identity statuses were related to drug use and previous delinquent behavior, but not recidivism. Foreclosed status youths were statistically unlikely to recidivate, use drugs, and reported fewer previous offenses. [source] Monitoring exposure to avian influenza viruses in wild mammalsMAMMAL REVIEW, Issue 3 2009KACI K. VANDALEN ABSTRACT 1Avian influenza (AI) viruses primarily circulate in wild waterfowl populations and are occasionally transmitted to domestic poultry flocks. However, the possible roles of other wildlife species, such as wild mammals, in AI virus ecology have not been adequately addressed. 2Due to their habitat and behaviour, many wild mammals may be capable of transmitting pathogens among wild and domestic populations. Exposure to AI viruses has been reported in an array of wild and domestic animals. The presence of wild mammals on farms has been identified as a risk factor for at least one poultry AI outbreak in North America. These reports suggest the need for seroprevalence studies examining the exposure of wild mammals to AI viruses. 3Serological tests are routinely used to assess domestic poultry, domestic swine and human exposure to influenza A viruses, but these tests have not been validated for use in wild mammals. As such, some of these protocols may require adjustments or may be inappropriate for use in serology testing of wild mammals. Herein, we review these serological techniques and evaluate their potential usefulness in AI surveillance of wild mammals. We call for care to be taken when applying serological tests outside their original area of validation, and for continued assay verification for multiple species and virus strains. [source] Item response theory: applications of modern test theory in medical educationMEDICAL EDUCATION, Issue 8 2003Steven M Downing Context Item response theory (IRT) measurement models are discussed in the context of their potential usefulness in various medical education settings such as assessment of achievement and evaluation of clinical performance. Purpose The purpose of this article is to compare and contrast IRT measurement with the more familiar classical measurement theory (CMT) and to explore the benefits of IRT applications in typical medical education settings. Summary CMT, the more common measurement model used in medical education, is straightforward and intuitive. Its limitation is that it is sample-dependent, in that all statistics are confounded with the particular sample of examinees who completed the assessment. Examinee scores from IRT are independent of the particular sample of test questions or assessment stimuli. Also, item characteristics, such as item difficulty, are independent of the particular sample of examinees. The IRT characteristic of invariance permits easy equating of examination scores, which places scores on a constant measurement scale and permits the legitimate comparison of student ability change over time. Three common IRT models and their statistical assumptions are discussed. IRT applications in computer-adaptive testing and as a method useful for adjusting rater error in clinical performance assessments are overviewed. Conclusions IRT measurement is a powerful tool used to solve a major problem of CMT, that is, the confounding of examinee ability with item characteristics. IRT measurement addresses important issues in medical education, such as eliminating rater error from performance assessments. [source] | ||||||||||||||||||||||||||||||||||||||||||||||