351 resultados para wavelength monitoring
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MHC-peptide tetramers have become essential tools for T-cell analysis, but few MHC class II tetramers incorporating peptides from human tumor and self-antigens have been developed. Among limiting factors are the high polymorphism of class II molecules and the low binding capacity of the peptides. Here, we report the generation of molecularly defined tetramers using His-tagged peptides and isolation of folded MHC/peptide monomers by affinity purification. Using this strategy we generated tetramers of DR52b (DRB3*0202), an allele expressed by approximately half of Caucasians, incorporating an epitope from the tumor antigen NY-ESO-1. Molecularly defined tetramers avidly and stably bound to specific CD4(+) T cells with negligible background on nonspecific cells. Using molecularly defined DR52b/NY-ESO-1 tetramers, we could demonstrate that in DR52b(+) cancer patients immunized with a recombinant NY-ESO-1 vaccine, vaccine-induced tetramer-positive cells represent ex vivo in average 1:5,000 circulating CD4(+) T cells, include central and transitional memory polyfunctional populations, and do not include CD4(+)CD25(+)CD127(-) regulatory T cells. This approach may significantly accelerate the development of reliable MHC class II tetramers to monitor immune responses to tumor and self-antigens.
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OBJECTIVE: Current hypertension guidelines stress the importance to assess total cardiovascular risk but do not describe precisely how to use ambulatory blood pressures in the cardiovascular risk stratification. METHOD: We calculated here global cardiovascular risk according to 2003 European Society of Hypertension/European Society of Cardiology guidelines in 127 patients in whom daytime ambulatory blood pressures were recorded and carotid/femoral ultrasonography performed. RESULTS: The presence of ambulatory blood pressures >or =135/85 mmHg shifted cardiovascular risk to higher categories, as did the presence of hypercholesterolemia and, even more so, the presence of atherosclerotic plaques. CONCLUSION: Further studies are, however, needed to define the position of ambulatory blood pressures in the assessment of cardiovascular risk.
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Some root-associated pseudomonads sustain plant growth by suppressing root diseases caused by pathogenic fungi. We investigated to which extent select cereal cultivars influence expression of relevant biocontrol traits (i.e., root colonization efficacy and antifungal activity) in Pseudomonas fluorescens CHA0. In this representative plant-beneficial bacterium, the antifungal metabolites 2,4-diacetylphloroglucinol (DAPG), pyrrolnitrin (PRN), pyoluteorin (PLT), and hydrogen cyanide (HCN) are required for biocontrol. To monitor host plant effects on the expression of biosynthetic genes for these compounds on roots, we developed fluorescent dual-color reporters suited for flow cytometric analysis using fluorescence-activated cell sorting (FACS). In the dual-label strains, the constitutively expressed red fluorescent protein mCherry served as a cell tag and marker for root colonization, whereas reporter fusions based on the green fluorescent protein allowed simultaneous recording of antifungal gene expression within the same cell. FACS analysis revealed that expression of DAPG and PRN biosynthetic genes was promoted in a cereal rhizosphere, whereas expression of PLT and HCN biosynthetic genes was markedly less sustained. When analyzing the response of the bacterial reporters on roots of a selection of wheat, spelt, and triticale cultivars, we were able to detect subtle species- and cultivar-dependent differences in colonization and DAPG and HCN gene expression levels. The expression of these biocontrol traits was particularly favored on roots of one spelt cultivar, suggesting that a careful choice of pseudomonad-cereal combinations might be beneficial to biocontrol. Our approach may be useful for selective single-cell level analysis of plant effects in other bacteria-root interactions.
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Liquid-chromatography (LC) high-resolution (HR) mass spectrometry (MS) analysis can record HR full scans, a technique of detection that shows comparable selectivity and sensitivity to ion transitions (SRM) performed with triple-quadrupole (TQ)-MS but that allows de facto determination of "all" ions including drug metabolites. This could be of potential utility in in vivo drug metabolism and pharmacovigilance studies in order to have a more comprehensive insight in drug biotransformation profile differences in patients. This simultaneous quantitative and qualitative (Quan/Qual) approach has been tested with 20 patients chronically treated with tamoxifen (TAM). The absolute quantification of TAM and three metabolites in plasma was realized using HR- and TQ-MS and compared. The same LC-HR-MS analysis allowed the identification and relative quantification of 37 additional TAM metabolites. A number of new metabolites were detected in patients' plasma including metabolites identified as didemethyl-trihydroxy-TAM-glucoside and didemethyl-tetrahydroxy-TAM-glucoside conjugates corresponding to TAM with six and seven biotransformation steps, respectively. Multivariate analysis allowed relevant patterns of metabolites and ratios to be associated with TAM administration and CYP2D6 genotype. Two hydroxylated metabolites, α-OH-TAM and 4'-OH-TAM, were newly identified as putative CYP2D6 substrates. The relative quantification was precise (<20 %), and the semiquantitative estimation suggests that metabolite levels are non-negligible. Metabolites could play an important role in drug toxicity, but their impact on drug-related side effects has been partially neglected due to the tremendous effort needed with previous MS technologies. Using present HR-MS, this situation should evolve with the straightforward determination of drug metabolites, enlarging the possibilities in studying inter- and intra-patients drug metabolism variability and related effects.
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The practice of sedation, including monitoring practice for digestive endoscopy, continues to evolve throughout the world. In many countries, including Switzerland, there is a trend towards increased utilization of sedation during both routine and advanced endoscopic procedures. Sedation improves patient satisfaction with endoscopy and also improves the quality of the examination. In addition, a trend can be observed towards an increasing use of propofol as the preferred sedative drug. Here we review the latest published data from surveys describing sedation and monitoring practice in different countries and compare them with our own data from successive nationwide surveys among Swiss gastroenterologists over a period of 20 years. This development between these socioeconomically very similar Western industrialized countries, however, shows some unique and surprising differences. In Germany and Switzerland, propofol use has become increasingly widespread, in Switzerland even to the extent that during the last few years propofol has overtaken benzodiazepine sedation, with an absolute majority of Swiss gastroenterologists using it without the assistance of an anesthesiologist. In addition, the change in Switzerland reflects a successful generalization of nonanesthesiologist-administered propofol (NAAP) sedation from the hospital setting to private practice.
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Digital holography microscopy (DHM) is an optical technique which provides phase images yielding quantitative information about cell structure and cellular dynamics. Furthermore, the quantitative phase images allow the derivation of other parameters, including dry mass production, density, and spatial distribution. We have applied DHM to study the dry mass production rate and the dry mass surface density in wild-type and mutant fission yeast cells. Our study demonstrates the applicability of DHM as a tool for label-free quantitative analysis of the cell cycle and opens the possibility for its use in high-throughput screening.
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Gas chromatography (GC) is an analytical tool very useful to investigate the composition of gaseous mixtures. However, hydrogen (H2) detection after a GC separation is only possible with a Thermal Conductivity Detector (TCD), a Helium Ionisation Detector (HID) or expensive Atomic Emission Detector (AED). Recently, indirect H2 detection by GC coupled to mass spectrometry (MS) was demonstrated but the mechanism of carrier gas protonation remained unclear. With electron impact as ionisation source of MS and helium (He) as GC carrier gas, H2 is not ionised according the expected Penning ionisation neither according to the Associative ionisation. Rearrangement ionisation (RI) was found to be the main channel for H2 and D2 ionisation under GC-MS conditions used in most of laboratories using GC-MS, leading to the formation of [He−H]+ and [He−D]+ ions.
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Ambulatory blood pressure monitoring (ABPM) is being used increasingly in both clinical practice and hypertension research. Although there are many guidelines that emphasize the indications for ABPM, there is no comprehensive guideline dealing with all aspects of the technique. It was agreed at a consensus meeting on ABPM in Milan in 2011 that the 34 attendees should prepare a comprehensive position paper on the scientific evidence for ABPM.This position paper considers the historical background, the advantages and limitations of ABPM, the threshold levels for practice, and the cost-effectiveness of the technique. It examines the need for selecting an appropriate device, the accuracy of devices, the additional information and indices that ABPM devices may provide, and the software requirements.At a practical level, the paper details the requirements for using ABPM in clinical practice, editing considerations, the number of measurements required, and the circumstances, such as obesity and arrhythmias, when particular care needs to be taken when using ABPM.The clinical indications for ABPM, among which white-coat phenomena, masked hypertension, and nocturnal hypertension appear to be prominent, are outlined in detail along with special considerations that apply in certain clinical circumstances, such as childhood, the elderly and pregnancy, and in cardiovascular illness, examples being stroke and chronic renal disease, and the place of home measurement of blood pressure in relation to ABPM is appraised.The role of ABPM in research circumstances, such as pharmacological trials and in the prediction of outcome in epidemiological studies is examined and finally the implementation of ABPM in practice is considered in relation to the issue of reimbursement in different countries, the provision of the technique by primary care practices, hospital clinics and pharmacies, and the growing role of registries of ABPM in many countries.
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The DRG classification provides a useful tool for the evaluation of hospital care. Indicators such as readmissions and mortality rates adjusted for the hospital Casemix could be adopted in Switzerland at the price of minor additions to the hospital discharge record. The additional information required to build patients histories and to identify the deaths occurring after hospital discharge is detailed.
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Introduction: As imatinib pharmacokinetics are highly variable, plasma levels differ largely between patients under the same dosage. Retrospective studies in chronic myeloid leukemia (CML) patients showed significant correlations between low levels and suboptimal response, as well as between high levels and poor tolerability. Monitoring of trough plasma levels, targeting 1000 μg/L and above, is thus increasingly advised. Our study was launched to assess prospectively the clinical usefulness of systematic imatinib TDM in CML patients. This preliminary analysis addresses the appropriateness of the dosage adjustment approach applied in this study, which targets the recommended trough level and allows an interval of 4-24 h after last drug intake for blood sampling. Methods: Blood samples from the first 15 patients undergoing 1st TDM were obtained 1.5-25 h after last dose. Imatinib plasma levels were measured by LC-MS/MS and the concentrations were extrapolated to trough based on a Bayesian approach using a population pharmacokinetic model. Trough levels were predicted to differ significantly from the target in 12 patients (10 <750 μg/L; 2 >1500 μg/L along with poor tolerance) and individual dose adjustments were proposed. 8 patients underwent a 2nd TDM cycle. Trough levels of 1st and 2nd TDM were compared, the sample drawn 1.5 h after last dose (during distribution phase) was excluded from the analysis. Results: Individual dose adjustments were applied in 6 patients. Observed concentrations extrapolated to trough ranged from 360 to 1832 μg/L (median 725; mean 810, CV 52%) on 1st TDM and from 720 to 1187 μg/L (median 950; mean 940, CV 18%) on 2nd TDM cycle. Conclusions: These preliminary results suggest that TDM of imatinib using a Bayesian interpretation is able to target the recommended trough level of 1000 μg/L and to reduce the considerable differences in trough level exposure between patients (with CV decreasing from 52% to 18%). While this may simplify blood collection in daily practice, as samples do not have to be drawn exactly at trough, the largest possible interval to last drug intake yet remains preferable to avoid sampling during distribution phase leading to biased extrapolation. This encourages the evaluation of the clinical benefit of a routine TDM intervention in CML patients, which the randomized Swiss I-COME trial aims to.
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BACKGROUND: There is increasing evidence for the clinical relevance of mucosal healing (MH) as therapeutic treatment goal in inflammatory bowel disease (IBD). We aimed to investigate by which method gastroenterologists monitor IBD activity in daily practice. METHODS: A questionnaire was sent to all board-certified gastroenterologists in Switzerland to specifically address their strategy to monitor IBD between May 2009 and April 2010. RESULTS: The response rate was 57% (153/270). Fifty-two percent of gastroenterologists worked in private practice and 48% worked in hospitals. Seventy-eight percent judged clinical activity to be the most relevant criterion for monitoring IBD activity, 15% chose endoscopic severity, and 7% chose biomarkers. Seventy percent of gastroenterologists based their therapeutic decisions on clinical activity, 24% on endoscopic severity, and 6% on biomarkers. The following biomarkers were used for IBD activity monitoring: CRP, 94%; differential blood count, 78%; fecal calprotectin (FC), 74%; iron status, 63%; blood sedimentation rate, 3%; protein electrophoresis, 0.7%; fecal neutrophils, 0.7%; and vitamin B12, 0.7%. Gastroenterologists in hospitals and those with ≤ 10 years of professional experience used FC more frequently compared with colleagues in private practice (P=0.035) and those with > 10 years of experience (P<0.001). CONCLUSIONS: Clinical activity is judged to be more relevant for monitoring IBD activity and guiding therapeutic decisions than endoscopic severity and biomarkers. As such, the accumulating scientific evidence on the clinical impact of mucosal healing does not yet seem to influence the management of IBD in daily gastroenterologic practice.
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BACKGROUND: As part of EUROCAT's surveillance of congenital anomalies in Europe, a statistical monitoring system has been developed to detect recent clusters or long-term (10 year) time trends. The purpose of this article is to describe the system for the identification and investigation of 10-year time trends, conceived as a "screening" tool ultimately leading to the identification of trends which may be due to changing teratogenic factors.METHODS: The EUROCAT database consists of all cases of congenital anomalies including livebirths, fetal deaths from 20 weeks gestational age, and terminations of pregnancy for fetal anomaly. Monitoring of 10-year trends is performed for each registry for each of 96 non-independent EUROCAT congenital anomaly subgroups, while Pan-Europe analysis combines data from all registries. The monitoring results are reviewed, prioritized according to a prioritization strategy, and communicated to registries for investigation. Twenty-one registries covering over 4 million births, from 1999 to 2008, were included in monitoring in 2010.CONCLUSIONS: Significant increasing trends were detected for abdominal wall anomalies, gastroschisis, hypospadias, Trisomy 18 and renal dysplasia in the Pan-Europe analysis while 68 increasing trends were identified in individual registries. A decreasing trend was detected in over one-third of anomaly subgroups in the Pan-Europe analysis, and 16.9% of individual registry tests. Registry preliminary investigations indicated that many trends are due to changes in data quality, ascertainment, screening, or diagnostic methods. Some trends are inevitably chance phenomena related to multiple testing, while others seem to represent real and continuing change needing further investigation and response by regional/national public health authorities.
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Background¦Erythrocyte MCV might be used as an inexpensive marker to predict and¦optimize the efficacy and tolerability of thiopurine therapy in IBD patients.¦Aim and methods¦This retrospective observational study aimed to assess the monitoring¦performances of MCV in patients under 3 months or more thiopurine treatment followed up¦in the Swiss IBD Cohort Study. All available MCV, white blood cells (WBC) and 6¦thioguanine nucleotide (6TGN) measurements, among others, were recorded. An IBD¦"flare" was defined as a composite outcome encompassing treatment change,¦colonoscopy, histology, CT scan or MRI reports showing active IBD lesions, occurrence of¦intestinal surgery and IBD-related hospitalisations. Whether MCV measurements predicted¦efficacy of thiopurine treatment was investigated by assessing the statistical association¦between the occurrence of IBD "flares", and the current or recent MCV values, taking into¦account the patient clustering and longitudinal aspect of data.¦Results¦140 patients (77 women), mean age 38 years (17-74), 104 diagnosed with¦Crohn's disease, 36 with ulcerative colitis, mean disease duration 8 years (0.25-36),¦receiving either azathioprine (n=125) or 6-mercaptopurine (n=15) were included, most of¦them over 3-year follow up.¦Thiopurines increased mean patient MCV by an average 5.8±5.2 fL, while¦patientsfluctuated by ±4.3 fL around their individual mean (p<0.001). They decreased¦WBC by an average of 2.4+/- 2.6 G/L (p<0.001).¦Significant associations were observed between the probability of flare occurrence and low¦current MVC (p=0.017) or high current WBC (p=0.009) and, with a relative risk of 3.7% for¦every fL of MCV decrease or 8% for every G/L of WBC increase. Both markers revealed¦some memory effect.¦Despite this, the performance of MCV and WBC to predict IBD "flare" remained rather¦limited, as it is less accurate than the 6-TGN-level , although only determined in a¦subgroup of patients in this study.¦Conclusion¦MCV and WBC deserve to be observed to check and monitor therapeutic¦exposure to thiopurine agents in IBD patients. Unfortunately, their predictive performance¦precludes their privileged use for optimization of therapy. Further prospective studies¦should suitably include the systematic measurement of metabolite concentration.