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Selected AbstractsStereodivergent Syntheses of Highly Substituted Enantiopure 4-Alkoxy-3,6-dihydro-2H -1,2-oxazines by Addition of Lithiated Alkoxyallenes to Carbohydrate-Derived AldonitronesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 6 2005Matthias Helms Abstract Additions of lithiated alkoxyallenes to D -glyceraldehyde-based nitrones 1 and 2 did not provide the expected hydroxylamine derivatives. Instead, a novel [3+3] cyclization process furnished 4-alkoxy-3,6-dihydro-2H -1,2-oxazines 9,14 with excellent syn selectivities and in moderate to good yields. Through precomplexation of the nitrones the corresponding anti -configured 1,2-oxazines 9, 10 and 13 could be obtained with high stereoselectivity. The reactions of nitrones 3,6, derived from D -erythrose or D -threose, generally proceeded less diastereoselectively, but reasonable yields of anti -configured 1,2-oxazines such as anti - 17 and anti - 19 could be obtained under Lewis acid promotion conditions. This was also the case for reactions of the D -arabinose-derived nitrone 7, which provided the anti -1,2-oxazines 23 and 24 with excellent diastereoselectivity and in good yields. Bis-nitrone 8 and lithiated methoxyallene furnished a mixture of six compounds, among which the major componentwas the C2 -symmetric syn/syn -1,2-oxazine 29. The diastereoselectivities of these reactions are interpreted on the basis of Dondoni's model for reactions between organolithium compounds and nitrones. The mechanisms for formation of 1,2-oxazines and of side products are discussed. The method introduced here seems to be of broad applicability and an excellent tool for diastereoselective chain elongation of carbohydrate derivatives, affording stereodefined precursors of aminopolyols and other highly functionalized compounds. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Optimal Control of Rigid-Link Manipulators by Indirect MethodsGAMM - MITTEILUNGEN, Issue 1 2008Rainer Callies Abstract The present paper is a survey and research paper on the treatment of optimal control problems of rigid-link manipulators by indirect methods. Maximum Principle based approaches provide an excellent tool to calculate optimal reference trajectories for multi-link manipulators with high accuracy. Their major drawback was the need to explicitly formulate the complicated system of adjoint differential equations and to apply the full apparatus of optimal control theory. This is necessary in order to convert the optimal control problem into a piecewise defined, nonlinear multi-point boundary value problem. An accurate and efficient access to first- and higher-order derivatives is crucial. The approach described in this paper allows it to generate all the derivative information recursively and simultaneously with the recursive formulation of the equations of motion. Nonlinear state and control constraints are treated without any simplifications by transforming them into sequences of systems of linear equations. By these means, the modeling of the complete optimal control problem and the accompanying boundary value problem is automated to a great extent. The fast numerical solution is by the advanced multiple shooting method JANUS. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Properties of 2,2,2-Trifluoroethanol/Water Mixtures: Acidity, Basicity, and DipolarityHELVETICA CHIMICA ACTA, Issue 2 2005Paz Sevilla, Sierra In this report, we focus our attention on the characterization of 2,2,2-trifluoroethanol(TFE)/H2O mixtures and describe their intrinsic parameters; i.e., solvent acidity (SA), solvent basicity (SB), and solvent dipolarity/polarizability (SPP), by the probe/homomorph-couple method for a range of mixtures from 0,100% (v/v) TFE. Variation of these parameters is not linear and has a singular and unpredictable behavior depending on the precise composition of the mixture. Based on these parameters, we describe the TFE-induced changes in some physical properties; i.e., viscosity (,), partial molar volume (V,), density (,), dielectric constant (,), vapor pressure (pv), and spectroscopic properties; i.e., NMR chemical shifts (,(1H)) of TFE Me group for all molar fractions studied. In addition, by means of CD studies, we report that formation of the secondary structure, as percentage of helical content, ,, of a polypeptide, poly(L -lysine), in several TFE/H2O mixtures is adequately described by these mixture parameters. SA, SB, and SPP of TFE/H2O mixtures provide an excellent tool for the interpretation of formation and stability of intramolecular H-bonds, and, thus, of secondary structures in polypeptides. [source] Establishment of T cell-specific and natural killer cell-specific unigene sets: towards high-throughput genomics of leukaemiaINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 6 2004J. Illiger Summary We report the establishment of highly non-redundant unigene sets consisting of cDNA clones derived from T lymphocytes and natural killer cells. Each set consists of 10 506 and 13 409 clones, respectively, arrayed on nylon membranes in duplicate. The sets provide an excellent tool for genome-wide gene expression analysis studies in immunology research. [source] Monitoring indicators of health care quality by means of a hospital register of tumoursJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 6 2008Maximino Redondo MD PhD Abstract Rationale, Hospital registers of tumours provide, on a continuous basis, information on differences in patterns of neoplasias and the results of the treatment strategies employed. Objective, In view of the scant publications on measures of health care quality in hospital tumour registers, the aim of our paper is to present the outcome of a study to monitor the results related to health care quality in oncology. Methods, Data are presented for cases recorded at the Hospital Costa del Sol over a period of 8 years. The sources of information are fundamentally the patient's medical record and the database of the Pathology Department. Results, A high proportion of patients (mean 50%, range 45,68%) were admitted to the hospital by the Emergency Department; there was a notably long delay between the appearance of the first symptoms and the occasion of the first hospital visit (median 65 days; range 60,75 days). Particularly striking was the corresponding delay for breast cancer patients, in most cases superior to 3 months. As was the case for the percentage of admissions by the Emergency Department, most of the indicators evaluated in this study present a significant improvement compared with the initial years of the Hospital Register of Tumours. Thus, non anatomic-pathological diagnoses represented around 7% (range 3,13%), while 43% of patients (range 28,57%) were given adjuvant treatment in the form of radiation therapy or chemotherapy. In 40% of cases (range 20,50%), the tumour stage was included in the clinical record by the doctor who was treating the patient (in the remaining cases, these data were recorded by the Tumour Registry); the date of appearance of the first symptoms was included in the medical record in 65% of cases (range 54,80%). According to the stage classification, the following 5-year survival rates were recorded: (I) 98%, (II) 94%, (III) 69% and (IV) 39% for breast cancer; (I) 93%, (II) 83%, (III) 68% and (IV) 12% for cancer of the colon; and (I) 100%, (II) 94%, (III) 79% and (IV) 53% for prostate cancer. Conclusion, The high percentage of patients admitted by the Emergency Department and the long delay between the appearance of the first symptoms reflect the deficient attention paid to this problem by patients and by primary health care services. Our results suggest that the Hospital Register of Tumours could constitute an excellent tool for monitoring the quality of health care systems for oncological patients. [source] An isolate and sequence database of infectious haematopoietic necrosis virus (IHNV)JOURNAL OF FISH DISEASES, Issue 6 2010S P Jonstrup Abstract In the field of fish diseases, the amount of relevant information available is enormous. Internet-based databases are an excellent tool for keeping track of the available knowledge in the field. Fishpathogens.eu was launched in June 2009 with the aim of collecting, storing and sorting data on fish pathogens. The first pathogen to be included was the rhabdovirus, viral haemorrhagic septicaemia virus (VHSV). Here, we present an extension of the database to also include infectious haematopoietic necrosis virus (IHNV). The database is developed, maintained and managed by the European Community Reference Laboratory for Fish Diseases and collaborators. It is available at http://www.fishpathogens.eu/ihnv. [source] Persistent parvovirus B19 infection detected by specific CD4+ T-cell responses in a patient with hepatitis and polyarthritisJOURNAL OF INTERNAL MEDICINE, Issue 3 2009G. Pongratz Abstract. We, here, report the case of a parvovirus B19 infection in an immunocompetent male patient presenting with acute hepatitis and polyarthritis. To follow the course of infection, we used a previously established enzyme-linked immunosorbent spot assay (ELISPOT) technique to detect CD4+ T cells specific for viral proteins. Even though symptoms of arthritis and hepatitis resolved in the immunocompetent individual within a few weeks, viral DNA in serum and CD4+ T cells specific for the viral protein VP1 unique region were still detectable more than 6 month after the onset of symptoms, thus pointing to a persistent state of infection. On the basis of this observation, we hypothesize that the intensity of liver involvement correlates with the likelihood of developing persistent parvovirus B19 infection. The described ELISPOT technique to detect virus-specific CD4+ T cells provides an excellent tool to analyse the state of parvovirus B19 infection for future studies to test this hypothesis. [source] PDF simulations of ethylene decomposition in tubular LDPE reactorsAICHE JOURNAL, Issue 2 2005Nitin H. Kolhapure Abstract The present study deals with turbulent reacting flow simulation inside low-density polyethylene (LDPE) tubular reactors, based on a detailed computational fluid dynamics (CFD) technique,transported probability density function (PDF) methods. The ability of the PDF methods to provide an exact representation of chemical source terms is ideally suited for coupling complex LDPE chemistry with small-scale fluid dynamic fluctuations in turbulent flow. LDPE chemistry with a total of 16 scalars provides an ideal test case for illustrating the applicability of an efficient chemistry algorithm based on in-situ adaptive tabulation. A particle-based Monte Carlo algorithm is used to solve the joint-composition PDF equation, whereas a finite-volume code is used to obtain hydrodynamic fields from the standard k,, turbulence model. The influence of feed temperature, initiator concentration, and degree of premixing is investigated to gain detailed knowledge of micromixing effects on steady-state reactor performance. The computational approach provides a low-cost alternative to experimental and pilot-plant tests for exploring a variety of design options when making important design and operational decisions, or for investigating unstable reactor operating conditions. The ability of a simplified, but otherwise equivalent multi-environment-presumed PDF model to predict turbulence,chemistry interactions close to physical reality is validated using the detailed transported PDF simulations. The transported PDF method is shown to be an excellent tool for obtaining fundamental information on turbulent reacting flows, as well as for deriving simplified models for faster and easier interpretation of these flows when developing safe and efficient chemical processes. © 2005 American Institute of Chemical Engineers AIChE J, 51: 585,606, 2005 [source] Synthesis of well-defined photoresist materials by SET-LRPJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2010Sven Fleischmann Abstract Single electron transfer-living radical polymerization (SET-LRP) provides an excellent tool for the straightforward synthesis of well-defined macromolecules. Heterogeneous Cu(0)- catalysis is employed to synthesize a novel photoresist material with high control over the molecular architecture. Poly(,-butyrolactone methacrylate)- co -(methyladamantly methacrylate) was synthesized. Kinetic experiments were conducted demonstrating that both monomers, ,-butyrolactone methacrylate (GBLMA) and methyl adamantly methacrylate (MAMA), are successfully homopolymerized. In both cases polymerization kinetic is of first order and the molecular weights increase linearly with conversion. The choice of a proper solvent was decisive for the SET-LRP process and organic solvent mixtures were found to be most suitable. Also, the kinetic of the copolymerization of GBLMA and MAMA was investigated. Following first order kinetics in overall monomer consumption and exhibiting a linear relationship between molecular weights and conversion a "living" process was established. This allowed for the straightforward synthesis of well-defined photoresist polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2251,2255, 2010 [source] Transient elastography and other noninvasive tests to assess hepatic fibrosis in patients with viral hepatitisJOURNAL OF VIRAL HEPATITIS, Issue 5 2009Laurent Castera Summary., The limitations of liver biopsy (invasive procedure, sampling errors, inter-observer variability and nondynamic fibrosis evaluation) have stimulated the search for noninvasive approaches for the assessment of liver fibrosis in patients with viral hepatitis. A variety of methods including the measurement of liver stiffness, using transient elastography, and serum markers, ranging from routine laboratory tests to more complex algorithms or indices combining the results of panels of markers, have been proposed. Among serum indices, Fibrotest has been the most extensively studied and validated. Transient elastography appears as a promising method but has been mostly validated in chronic hepatitis C with performance equivalent to that of serum markers for the diagnosis of significant fibrosis. The combination of both approaches as first-line assessment of liver fibrosis could avoid the performance of liver biopsy in the majority of patients with chronic hepatitis C, a strategy that deserves further evaluation in patients with hepatitis B or HIV-HCV coinfection. Transient elastography also appears to be an excellent tool for early detection of cirrhosis and may have prognostic value in this setting. Guidelines are now awaited for the use of noninvasive methods in clinical practice. [source] Novel polymerase chain reaction primers for the specific detection of bacterial copper P-type ATPases gene sequences in environmental isolates and metagenomic DNALETTERS IN APPLIED MICROBIOLOGY, Issue 6 2010R. De la Iglesia Abstract Aims:, In the last decades, the worldwide increase in copper wastes release by industrial activities like mining has driven environmental metal contents to toxic levels. For this reason, the study of the biological copper-resistance mechanisms in natural environments is important. Therefore, an appropriate molecular tool for the detection and tracking of copper-resistance genes was developed. Methods and Results:, In this work, we designed a PCR primer pair to specifically detect copper P-type ATPases gene sequences. These PCR primers were tested in bacterial isolates and metagenomic DNA from intertidal marine environments impacted by copper pollution. As well, T-RFLP fingerprinting of these gene sequences was used to compare the genetic composition of such genes in microbial communities, in normal and copper-polluted coastal environments. New copper P-type ATPases gene sequences were found, and a high degree of change in the genetic composition because of copper exposure was also determined. Conclusions:, This PCR based method is useful to track bacterial copper-resistance gene sequences in the environment. Significance and Impact of the Study:, This study is the first to report the design and use of a PCR primer pair as a molecular marker to track bacterial copper-resistance determinants, providing an excellent tool for long-term analysis of environmental communities exposed to metal pollution. [source] Optimizing periodic inspections in chemical plants by corrosion monitoringMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 12 2007M. Winkelmans An efficient industrial corrosion monitoring system would give information about the corrosion activity and corrosion damage of critical components within a chemical plant in real time. A research project to develop an industrial tool for the simultaneous monitoring of general and localized corrosion was initiated. General and localized corrosion can be monitored by combining several non-destructive techniques. An industrial probe for corrosion monitoring is an excellent tool for an intelligent material selection, to identify critical process conditions or to optimize the use of corrosion inhibitors. The highest added value of an industrial tool for corrosion monitoring is its capacity to optimize periodic inspections. [source] Kaizen: A Method of Process Improvement in the Emergency DepartmentACADEMIC EMERGENCY MEDICINE, Issue 12 2009Gregory H. Jacobson MD Abstract Introduction:, Recent position statements from health care organizations have placed a strong emphasis on continuous quality improvement (CQI). CQI finds many of its roots in kaizen, which emphasizes small, low-cost, low-risk improvements. Based on the successful Kaizen Programs at organizations such as Toyota, the authors thought the emergency department (ED) would be an ideal environment to benefit from such a program. Objectives:, The authors sought to create a CQI program using a suggestion-based model that did not require a large time commitment, was easy to implement, and had the potential to empower all physicians in the department. It would not take the place of other improvement efforts, but instead augment them. The hypothesis was that such a program would foster sustainable engagement of emergency physicians in system improvement efforts and lead to a continuous stream of low-cost implementable system improvement interventions. Methods:, A CQI program was created for the physician staff of the Department of Emergency Medicine at Vanderbilt University Medical Center, focusing on a suggestion-based model using kaizen philosophy. Lectures teaching kaizen philosophy were presented. Over the past 4 years, a methodology was developed utilizing a Web-based application, the Kaizen Tracker, which aids in the submission and implementation of suggestions that are called kaizen initiatives (KIs). The characteristics of the KIs submitted, details regarding resident and faculty participation, and the effectiveness of the Kaizen Tracker were retrospectively reviewed. Results:, There were 169, 105, and 101 KIs placed in the postimplementation calendar years 2006, 2007, and 2008, respectively. Seventy-six percent of KIs submitted thus far have identified a "process problem." Fifty-three percent of KIs submitted have led to operational changes within the ED. Ninety-three percent of the resident physicians entered at least one KI, and 73% of these residents submitted more than one KI. Sixty-nine percent of the attendings entered at least one KI, and 89% of these attendings submitted more than one KI. Conclusions:, Over the past 4 years, the Kaizen Program at Vanderbilt has been widely and frequently used within the ED. It has resulted in over 400 changes in our adult ED system and has met the challenge of using CQI to drive ED improvements. There are limitations to this study, including the fact that its impact on patient outcomes remains unknown. However, this Kaizen Program may be an excellent tool for other departments to assist with quality improvement and should be studied with a multicenter prospective approach. [source] Magnetic studies of the carbothermal effect on LiFePO4PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2006A. Ait-Salah Abstract The effect of carbon coating on the properties of LiFePO4 particles is studied from magnetic measurements. Magnetization experiments are an excellent tool to detect very low concentrations of iron-based impurities (<1 ppm) which are poisoning the phospho-olivine used as positive electrode material in rechargeable Li-ion batteries. The results indicate that addition of 5% carbon withdraws traces of the Fe(III) phase such as Fe2P and/or Fe2O3. This carbothermal effect appears to be beneficial for long-term application of LiFePO4 materials in Li-ion batteries. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Ultrafast X-ray diffraction in liquid, solution and gas: present status and future prospectsACTA CRYSTALLOGRAPHICA SECTION A, Issue 2 2010Jeongho Kim In recent years, the time-resolved X-ray diffraction technique has been established as an excellent tool for studying reaction dynamics and protein structural transitions with the aid of 100,ps X-ray pulses generated from third-generation synchrotrons. The forthcoming advent of the X-ray free-electron laser (XFEL) will bring a substantial improvement in pulse duration, photon flux and coherence of X-ray pulses, making time-resolved X-ray diffraction even more powerful. This technical breakthrough is envisioned to revolutionize the field of reaction dynamics associated with time-resolved diffraction methods. Examples of candidates for the first femtosecond X-ray diffraction experiments using highly coherent sub-100,fs pulses generated from XFELs are presented in this paper. They include the chemical reactions of small molecules in the gas and solution phases, solvation dynamics and protein structural transitions. In these potential experiments, ultrafast reaction dynamics and motions of coherent rovibrational wave packets will be monitored in real time. In addition, high photon flux and coherence of XFEL-generated X-ray pulses give the prospect of single-molecule diffraction experiments. [source] The myeloid-related proteins 8 and 14 complex, a novel ligand of toll-like receptor 4, and interleukin-1, form a positive feedback mechanism in systemic-onset juvenile idiopathic arthritisARTHRITIS & RHEUMATISM, Issue 3 2009Michael Frosch Objective Fever of unknown origin is a diagnostic challenge in children, especially for differentiation of systemic-onset juvenile idiopathic arthritis (systemic-onset JIA) and infectious diseases. We undertook this study to analyze the relevance of myeloid-related proteins (MRPs) 8 and 14, endogenous activators of Toll-like receptor 4, in diagnosis and pathogenesis of systemic-onset JIA. Methods Serum concentrations of MRP-8/MRP-14 were analyzed in 60 patients with systemic-onset JIA, 85 patients with systemic infections, 40 patients with acute lymphoblastic leukemia, 5 patients with acute myeloblastic leukemia, 18 patients with neonatal-onset multisystem inflammatory disease (NOMID), and 50 healthy controls. In addition, we investigated the link between interleukin-1, (IL-1,) and MRP-8/MRP-14 in systemic-onset JIA. Results Serum MRP-8/MRP-14 concentrations were significantly (P < 0.001) elevated in patients with active systemic-onset JIA (mean ± 95% confidence interval 14,920 ± 4,030 ng/ml) compared with those in healthy controls (340 ± 70 ng/ml), patients with systemic infections (2,640 ± 720 ng/ml), patients with acute lymphoblastic leukemia (650 ± 280 ng/ml), patients with acute myeloblastic leukemia (840 ± 940 ng/ml), and patients with NOMID (2,830 ± 580 ng/ml). In contrast to C-reactive protein levels, MRP-8/MRP-14 concentrations distinguished systemic-onset JIA from infections, with a specificity of 95%. MRP-14 in serum of patients with systemic-onset JIA was a strong inducer of IL-1, expression in phagocytes. Conclusion The analysis of MRP-8/MRP-14 in serum is an excellent tool for the diagnosis of systemic-onset JIA, allowing early differentiation between patients with systemic-onset JIA and those with other inflammatory diseases. MRP-8/MRP-14 and IL-1, represent a novel positive feedback mechanism activating phagocytes via 2 major signaling pathways of innate immunity during the pathogenesis of systemic-onset JIA. [source] WT1 gene expression: an excellent tool for monitoring minimal residual disease in 70% of acute myeloid leukaemia patients , results from a single-centre studyBRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2004Mette Østergaard Summary Following induction chemotherapy for acute myeloid leukaemia (AML), sensitive determination of minimal residual disease (MRD) in patients achieving complete remission (CR) should enable the detection of early relapse and allow intervention at a more favourable stage than at overt relapse. We have determined the expression levels of the Wilms' tumour gene (WT1) by real-time quantitative polymerase chain reaction (RQ-PCR) in peripheral blood and bone marrow in 133 newly diagnosed AML patients and compared them with those in healthy volunteers. At diagnosis, the WT1 level exceeded normal expression in 118 of 133 (89%) patients, and was high enough to allow for detection of a WT1 decrease of least 1000-fold in 98 of 133 (74%) patients following induction therapy. Concomitant monitoring of fusion transcripts (PML-RAR,, AML1-ETO, MLL-MLL, CBF, - MYH11, or DEK-CAN) in 38 patients identified different relationships between WT1 and fusion transcript levels, the AML1-ETO group showing remarkably low levels of WT1 compared with fusion transcript. In 32 patients analysed longitudinally there was close concordance between relapse and increased WT1 levels. Parallel longitudinal monitoring of WT1 and fusion transcript showed close correlation in 18 of 18 patients. We conclude that WT1 expression by RQ-PCR may be employed as a tool to detect MRD in the majority of fusion transcript-negative AML patients. [source] Imaging auditory hallucinations in schizophreniaACTA NEUROPSYCHIATRICA, Issue 2 2006D. K. Tracy It is increasingly recognized that there are a heterogeneous range of symptoms within the syndrome of schizophrenia and that some of these also occur frequently within other psychiatric conditions. An approach similar to that in neuropsychology, where cases are grouped based on a discrete deficit, or in this case a discrete symptom, rather than a cause or diagnosis, may be useful in exploring the neural correlates of psychotic symptomatology. Functional neuroimaging provides an excellent tool for investigating the in vivo cortical function of patients with schizophrenia. Auditory verbal hallucinations are one of the most commonly occurring psychotic symptoms in schizophrenia; and this paper examines the progress that has been made in utilizing neuroimaging techniques to investigate auditory hallucinations in schizophrenia and review potential implications for treatment and future directions for research. [source] Three-dimensional reconstruction of the ankle by means of ultrathin slice plastinationCLINICAL ANATOMY, Issue 2 2007Mircea-Constantin Sora Abstract Computerized reconstruction of anatomical structures is becoming very useful for developing anatomical teaching modules and animations. Although databases exist consisting of serial sections derived from frozen cadaver material, plastination represents an alternate method for developing anatomical data useful for computerized reconstruction. Plastination is used as an excellent tool for studying different anatomical and clinical questions. The sheet plastination technique is unique because it offers the possibility to produce transparent slices series, which can easily be processed morphometrically. The purpose of this study was to describe a method for developing a computerized model of the human ankle using plastinated slices. This method could be applied to reconstruct any desired region of the human body. A human ankle was obtained, plastinated, sectioned, and subjected to 3D computerized reconstruction using WinSURF modeling system (SURFdriver Software). Qualitative observations revealed that the morphological features of the model were consistent with those displayed by typical cadaveric specimens. Morphometric analysis indicated that the model did not significantly differ from a sample of cadaveric specimens. These data support the use of plastinates for generating tissues sections useful for 3D computerized modeling. Clin. Anat. 20:196,200, 2007. © 2006 Wiley-Liss, Inc. [source] Characteristics of patients with abnormal stress technetium Tc 99m sestamibi SPECT studies without significant coronary artery diameter stenosesCLINICAL CARDIOLOGY, Issue 11 2003Peter Ammann M.D. Abstract Background: Single-photon emission computed tomography (SPECT) sestamibi (MIBI) is an excellent tool for detection of coronary artery disease (CAD), preoperative risk assessment, and follow-up management after coronary revas-cularization. While the sensitivity of MIBI SPECT for detecting CAD has been reported to exceed 90%, the specificity ranges between 53,100%. Hypothesis: The study was undertaken to assess characteristics of patients with abnormal stress technetium Tc 99m sestamibi SPECT (MIBI) studies without significant coronary artery diameter stenoses (< 50%). Methods: Between January 1999 and November 2000, 270 consecutive patients were referred for coronary angiography due to reversible MIBI uptake defects during exercise. In 41 patients (15%; 39% women, mean age 59 ± 9 years), reversible MIBI uptake defects were assessed although coronary angiography showed no significant CAD. These patients were compared with age- and gender-matched patients with perfusion abnormalities (39% women, mean age 60 ± 9 years), due to significant CAD (coronary artery stenosis > 50%). Results: There were no significant differences between the two groups regarding body mass index, left bundle-branch block (LBBB), or method of stress test (dipyridamole in patients with LBBB or physical inactivity [n= 11] and exercise in all the others [n= 30]). Left ventricular hypertrophy (44 vs. 23%, p = 0.05) and left anterior fascicularblock (LAFB) (17 vs. 0%, p = 0.005) were more common in patients with perfusion abnormalities with no significant CAD, whereas ST-segment depression during exercise (17 vs. 37% p = 0.05) and angina during exercise (15 vs. 29%, p = 0.02) were significantly less common than in patients with abnormal MIBI perfusion studies and angiographically significant CAD. Sestamibi uptake defects during exercise were significantly smaller in patients without significant CAD than in matched controls with significant CAD (p < 0.0004). Conclusion: Of 270 consecutive patients, 41 (15%) referred to coronary angiography due to reversible MIBI uptake defects showed coronary artery stenoses <50%. Twenty-six (10%) of these presented angiographically normal coronary arteries. The significantly higher proportion of left ventricular hypertrophy and LAFB in patients with reversible MIBI uptake defects without significant CAD suggest microvascular disease, angiographically underestimated CAD, and conduction abnormalities as underlying mechanisms. [source] Anterior,posterior patterning of neural differentiated embryonic stem cells by canonical Wnts, Fgfs, Bmp4 and their respective antagonistsDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 8 2009Marijke Hendrickx Embryonic stem (ES) cells are pluripotent and can differentiate into every cell type of the body. Next to their potential in regenerative medicine, they are excellent tools to study embryonic development. In this work the processes of neural induction and neural patterning along the antero-posterior (A/P) body axis are studied and evidence suggests a two step mechanism for these events. First, neural induction occurs by default in the primitive ectoderm, forming anterior neural tissue and thereafter, a series of factors can posteriorize this anterior neurectoderm. In a gain-of-function/loss-of-function approach using mouse ES cells, we show that Fgf2 has the strongest caudalizing potential of all Fgfs tested. Furthermore, Bmp4 and Wnt3a, but not Wnt1, can caudalize the neurectodermal cells. The effect of the antagonists of these factors was also examined and though Dkk1 and Noggin clearly have an effect that opposes that of Wnt3a and Bmp4 respectively, they fail to anteriorize the neurectoderm. The patterning effect of SU5402, an Fgf receptor inhibitor, was rather limited. These data confirm that in the mouse, two steps are involved in neural patterning and we show that while Fgf4, Fgf8 and Wnt1 have no strong patterning effect, Fgf2, Wnt3a and Bmp4 are strong posteriorizing factors. [source] Prospective cohort study comparing sequential organ failure assessment and acute physiology, age, chronic health evaluation III scoring systems for hospital mortality prediction in critically ill cirrhotic patientsINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2006Y-C Chen Summary The aim of the study was to evaluate the usefulness of sequential organ failure assessment (SOFA) and acute physiology, age, chronic health evaluation III (APACHE III) scoring systems obtained on the first day of intensive care unit (ICU) admission in predicting hospital mortality in critically ill cirrhotic patients. The study enrolled 102 cirrhotic patients consecutively admitted to ICU during a 1-year period. Twenty-five demographic, clinical and laboratory variables were analysed as predicators of survival. Information considered necessary to calculate the Child,Pugh, SOFA and APACHE III scores on the first day of ICU admission was also gathered. Overall hospital mortality was 68.6%. Multiple logistic regression analysis revealed that mean arterial pressure, SOFA and APACHE III scores were significantly related to prognosis. Goodness-of-fit was good for the SOFA and APACHE III models. Both predictive models displayed a similar degree of the best Youden index (0.68) and overall correctness (84%) of prediction. The SOFA and APACHE III models displayed good areas under the receiver,operating characteristic curve (0.917 ± 0.028 and 0.912 ± 0.029, respectively). Finally, a strong and significant positive correlation exists between SOFA and APACHE III scores for individual patients (r2 = 0.628, p < 0.001). This investigation confirms the grave prognosis for cirrhotic patients admitted to ICU. Both SOFA and APACHE III scores are excellent tools to predict the hospital mortality in critically ill cirrhotic patients. The overall predictive accuracy of SOFA and APACHE III is superior to that of Child,Pugh system. The role of these scoring systems in describing the dynamic aspects of clinical courses and allocating ICU resources needs to be clarified. [source] Microfluidic chips for mass spectrometry-based proteomicsJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 5 2009Jeonghoon Lee Abstract Microfluidic devices coupled to mass spectrometers have emerged as excellent tools for solving the complex analytical challenges associated with the field of proteomics. Current proteome identification procedures are accomplished through a series of steps that require many hours of labor-intensive work. Microfluidics can play an important role in proteomic sample preparation steps prior to mass spectral identification such as sample cleanup, digestion, and separations due to its ability to handle small sample quantities with the potential for high-throughput parallel analysis. To utilize microfluidic devices for proteomic analysis, an efficient interface between the microchip and the mass spectrometer is required. This tutorial provides an overview of the technologies and applications of microfluidic chips coupled to mass spectrometry for proteome analysis. Various approaches for combining microfluidic devices with electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) are summarized and applications of chip-based separations and digestion technologies to proteomic analysis are presented. Copyright © 2009 John Wiley & Sons, Ltd. [source] Graminicide resistance in a blackgrass (Alopecurus myosuroides) population correlates with insensitivity of acetyl-CoA carboxylasePLANT CELL & ENVIRONMENT, Issue 1 2004L. J. PRICE ABSTRACT The appearance of biotypes of the annual grass weed black-grass (Alopecurus myosuroides L. Huds), which are resistant to certain graminicides, is the most significant example of acquired resistance to herbicides seen so far in European agriculture. An investigation was perfomed into the basis of the specific cross-resistance to cyclohexanedione (CHD) and aryloxyphenoxypropionoic acid (AOPP) herbicides in the ,Notts A1' population of A. myosuroides, which survived treatment of fields with recommended rates of AOPP herbicides. In comparison with the wild-type ,Rothamsted' population, the resistant biotype showed over 100-fold resistance to these herbicides in a hydroponic growth system. Biosynthesis of fatty acids and activity of crude extracts of acetyl-CoA carboxylase (ACCase) were commensurately less sensitive to these herbicides in Notts A1 compared with the Rothamsted biotype. These data are consistent with the hypothesis that the highly resistant population has arisen through selection of a mutant ACCase which is much less sensitive to the AOPP and CHD graminicides. Rapidly growing cell suspension cultures established from the Notts A1 population also showed high resistance indices for CHD or AOPP herbicides compared with cultures from the Rothamsted biotype. Fatty acid biosynthesis and ACCase activity in the cell suspensions were similarly sensitive towards the graminicides to those in the foliar tissue counterparts of the resistant and sensitive populations. Moreover, purification of the main (chloroplast) isoform of acetyl-CoA carboxylase showed that this enzyme from the Notts A1 population was over 200-fold less sensitive towards the AOPP herbicide, quizalofop, than the equivalent isoform from the Rothamsted population. These data again fully supported the proposal that resistance in the Notts biotype is due to an insensitive acetyl-CoA carboxylase isoform. Overall, cell suspensions were also demonstrated to be excellent tools for further investigation of the molecular basis of the high level herbicide resistance which is prone to occur in A. myosuroides. [source] | ||||||||||||||||||||||