108 resultados para matrix metalloproteinase 16


Relevância:

20.00% 20.00%

Publicador:

Resumo:

A selective and sensitive method was developed for the simultaneous quantification of seven typical antipsychotic drugs (cis-chlorprothixene, flupentixol, haloperidol, levomepromazine, pipamperone, promazine and zuclopenthixol) in human plasma. Ultra-high performance liquid chromatography (UHPLC) was used for complete separation of the compounds in less than 4.5min on an Acquity UPLC BEH C18 column (2.1mm×50mm; 1.7μm), with a gradient elution of ammonium formate buffer pH 4.0 and acetonitrile at a flow rate of 400μl/min. Detection was performed on a tandem quadrupole mass spectrometer (MS/MS) equipped with an electrospray ionization interface. A simple protein precipitation procedure with acetonitrile was used for sample preparation. Thanks to the use of stable isotope-labeled internal standards for all analytes, internal standard-normalized matrix effects were in the range of 92-108%. The method was fully validated to cover large concentration ranges of 0.2-90ng/ml for haloperidol, 0.5-90ng/ml for flupentixol, 1-450ng/ml for levomepromazine, promazine and zuclopenthixol and 2-900ng/ml for cis-chlorprothixene and pipamperone. Trueness (89.1-114.8%), repeatability (1.8-9.9%), intermediate precision (1.9-16.3%) and accuracy profiles (<30%) were in accordance with the latest international recommendations. The method was successfully used in our laboratory for routine quantification of more than 500 patient plasma samples for therapeutic drug monitoring. To the best of our knowledge, this is the first UHPLC-MS/MS method for the quantification of the studied drugs with a sample preparation based on protein precipitation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paleomagnetic investigations carried out in the 70's on Oligo-Miocene volcanics of Sardinia have demonstrated that the island was turned by 35-30 degrees clockwise from 33 Ma up to 3-1-20.5 Ma and rotated counterclockwise in a few million years [De Jong et al., 1969, 1973; Bobier et Coulon, 1970; Coulon et al., 1974; Manzoni, 1974, 1975; Bellon rr nl.. 1977: Edel et Lortscher, 1977; Edel, 1979, 1980]. Since then, the end of the rotation fixed at 19 Ma by Montigny er al. [1981] was the subject of discussions and several studies associating paleomagnetism and radiometric dating were undertaken [Assorgia er al., 1994: Vigliotti et Langenheim, 1995: Deino et al., 1997; Gattacceca rt Deino, 1999]. This is a contribution to this debate that is hampered by thr important secular variation recorded in the volcanics. The only way to get our of this problem is to sample series of successive flows as completely as possible, and to reduce the effect of secular variation by the calculation of means. Sampling was performed north of Bonorva in 5 pyroclastic flows that belong to the upper ignimbritic series SI2 according to Coulon rr nl. [1974] or LBLS according to Assorgia et al. [1997] (fig. I). Ar-40/Ar-39 dating of biotites from the debris flow (MDF) has yielded an age or 18.35 +/- 0.03 Ma [Dubois, 2000]. Five of the investigated sites are located beneath the debris flow ITV, TVB, TVD, SPM85, SPM86), one site was cured in the matrix of the debris flow (MDF) and one in 4 metric blocks included in the flow (DFC). Another site was sampled in the upper ash flow (PDM) that marks the end of the pyroclastic activity, just before the marine transgression. According to micropaleontological and radiometric dating this transgression has occurred between 18.35 and 17.6 Ma [Dubois, 2000]. After removal of a soft viscous component, the thermal demagnetization generally shows a univectorial behaviour of the remanent magnetization (fig. 2a). The maximum unblocking temperatures of 580-620 degrees (tab. I) and a rapid saturation below 100 mT (fig. 3) indicate that the carrier of the characteristic magnetization is magnetite. The exception comes: from the upper site PDM in which were found two characteristic components, one with a normal polarity and low unblocking temperatures up to 350 degreesC and one with a reversed polarity and maximum unblocking temperatures at 580-600 degreesC of magnetite. After calculation of a mean direction for each flow, the mean << Al >> direction 4 degrees /57 degrees (alpha (95) = 13 degrees) computed with the mean directions for the 5 flows may be considered as weakly affected by secular variation. But the results require a more careful examination. The declinations are N to NNW beneath the debris flow. NNW in the debris flow. and NNE (or SSW) above the debris flow, The elongated distribution of the directions obtained at sites TVB and TVD. scattered from the mean direction of TV to the mean direction of MDF is interpreted as due to partial overprinting during the debris How volcanic episode, The low temperature component PDMa is likely related to the alteration seen on thin sections and is also viewed as an overprint. As NNE/SSW directions occur as well below (mean direction << B >> : 5 degrees /58 degrees) as above the debris flow (PDMb : 200 degrees/-58 degrees). the NNW directions (<< C >> : 337 degrees /64 degrees) associated with the debris flow volcanism may be interpreted as resulting from a magnetic field excursion. According to the polarity scale of Cande and Kent [1992, 1995] and the radiometric age of MDF, the directions with normal polarity (TV, TVB, TVD, SPM85. SPM86a. MDF. DFC) may represent the period 5En. while the directions with reversed polarity PDMb and SPM86b were likely acquired during the period 5Dr. Using the mean << Al >> direction, the mean << B >>, or the PDM direction (tab. I). the deviation in declination with the direction of stable Europe 6.4 degrees /58.7 degrees (alpha (95) = 8 degrees) for a selection of 4 middle Tertiary poles by Besse et Courtillot [1991] or 7 degrees /56 degrees (alpha (95) = 3 degrees) for 19 poles listed by Edel [1980] can be considered as negligible. Using the results from the uppermost ignimbritic layer of Anglona also emplaced around 18.3 Ma [Odin rt al.. 1994]. the mean direction << E >> (3 degrees /51.5 degrees) leads to the same conclusion. On the contrary, when taking into account all dated results available for the period 5En (mean direction << D >> 353 degrees /56 degrees for 45 sites) (tab. II). the deviation 13 degrees is much more significant. As the rotation of Sardinia started around 21-20.5 Ma. the assumption of a constant velocity of rotation and the deviations of the Sardinia directions with respect to the stable Europe direction locate the end of the motion between 18.3 and 17.2 or 16.7 Ma (fig. 4). During the interval 18.35-17.5 Ma, the marine transgression took place. At the same period a NE-SW shortening interpreted as resulting from the collision of Sardinia with Apulia affected different parts of the island [Letouzey et al., 1982]. Consequently, the new paleomagnetic results and the tectono-sedimentary evolution are in favour of an end of the rotation at 17.5-18 Ma.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A traditional photonic-force microscope (PFM) results in huge sets of data, which requires tedious numerical analysis. In this paper, we propose instead an analog signal processor to attain real-time capabilities while retaining the richness of the traditional PFM data. Our system is devoted to intracellular measurements and is fully interactive through the use of a haptic joystick. Using our specialized analog hardware along with a dedicated algorithm, we can extract the full 3D stiffness matrix of the optical trap in real time, including the off-diagonal cross-terms. Our system is also capable of simultaneously recording data for subsequent offline analysis. This allows us to check that a good correlation exists between the classical analysis of stiffness and our real-time measurements. We monitor the PFM beads using an optical microscope. The force-feedback mechanism of the haptic joystick helps us in interactively guiding the bead inside living cells and collecting information from its (possibly anisotropic) environment. The instantaneous stiffness measurements are also displayed in real time on a graphical user interface. The whole system has been built and is operational; here we present early results that confirm the consistency of the real-time measurements with offline computations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Transplantation of human embryonic stem cell-derived cardiomyocytes (hESC-CM) for cardiac regeneration is hampered by the formation of fibrotic tissue around the grafts, preventing electrophysiological coupling. Investigating this process, we found that: (1) beating hESC-CM in vitro are embedded in collagens, laminin and fibronectin, which they bind via appropriate integrins; (2) after transplantation into the mouse heart, hESC-CM continue to secrete collagen IV, XVIII and fibronectin; (3) integrin expression on hESC-CM largely matches the matrix type they encounter or secrete in vivo; (4) co-transplantation of hESC-derived endothelial cells and/or cardiac progenitors with hESC-CM results in the formation of functional capillaries; and (5) transplanted hESC-CM survive and mature in vivo for at least 24 weeks. These results form the basis of future developments aiming to reduce the adverse fibrotic reaction that currently complicates cell-based therapies for cardiac disease, and to provide an additional clue towards successful engraftment of cardiomyocytes by co-transplanting endothelial cells.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this pilot project was to evaluate the feasibility of assessing the deposited particle dose in the lungs by applying the dynamic light scattering-based methodology in exhaled breath condensateur (EBC). In parallel, we developed and validated two analytical methods allowing the determination of inflammatory (hydrogen peroxide - H2O2) and lipoperoxidation (malondialdehyde - MDA) biomarkers in exhaled breath condensate. Finally, these methods were used to assess the particle dose and consecutive inflammatory effect in healthy nonsmoker subjects exposed to environmental tobacco smoke in controlled situations was done.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Le présent rapport décrit les grandes tendances qui se dégagent des résultats de l'Enquête SMASH 2002 et propose quelques hypothèses pour éclairer la compréhension et les enjeux de la situation actuelle ainsi que des pistes de réflexion pour l'avenir. Cette étude repose sur deux approches complémentaires de la santé: l'une donne la primauté aux aspects sociologiques des conduites de santé ("lifestyle"); l'autre, de nature épidémiologique, met l'accent sur la prévalence des comportements et procède à des analyses dans divers sous-groupes ou dans le temps. L'étude SMASH 2002 fournit une photographie de la situation des adolescents et de leur état de santé : besoins et comportements de santé, facteurs associés et évaluation des grands changements intervenus depuis une dizaine d'années. Ces données doivent permettre de réfléchir à une planification optimale des services de soins et des programmes de prévention et de promotion de la santé en faveur des adolescents. [extraits du résumé des auteurs]

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Using both conventional fluorescence and confocal laser scanning microscopy we have investigated whether or not stabilization of isolated human erythroleukemic nuclei with sodium tetrathionate can maintain in the nuclear matrix the same spatial distribution of three polypeptides (M(r) 160 kDa and 125 kDa, previously shown to be components of the internal nuclear matrix plus the 180-kDa nucleolar isoform of DNA topoisomerase II) as seen in permeabilized cells. The incubation of isolated nuclei in the presence of 2 mM sodium tetrathionate was performed at 0 degrees C or 37 degrees C. The matrix fraction retained 20-40% of nuclear protein, depending on the temperature at which the chemical stabilization was executed. Western blot analysis revealed that the proteins studied were completely retained in the high-salt resistant matrix. Indirect immunofluorescence experiments showed that the distribution of the three antigens in the final matrix closely resembled that detected in permeabilized cells, particularly when the stabilization was performed at 37 degrees C. This conclusion was also strengthened by analysis of cells, isolated nuclei and the nuclear matrix by means of confocal laser scanning microscopy. We conclude that sodium tetrathionate stabilization of isolated nuclei does not alter the spatial distribution of some nuclear matrix proteins.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Allele frequencies and forensically relevant population statistics of 16 STR loci, including the new European Standard Set (ESS) loci, were estimated from 668 unrelated individuals of Caucasian appearance living in different parts of Switzerland. The samples were amplified with a combination of the following three kits: AmpFlSTR® NGM SElect?, PowerPlex® ESI17 and PowerPlex® ESX 17. All loci were highly polymorphic and no significant departure from Hardy-Weinberg equilibrium and linkage equilibrium was detected after correction for sampling.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Doxorubicin is an antineoplasic agent active against sarcoma pulmonary metastasis, but its clinical use is hampered by its myelotoxicity and its cumulative cardiotoxicity, when administered systemically. This limitation may be circumvented using the isolated lung perfusion (ILP) approach, wherein a therapeutic agent is infused locoregionally after vascular isolation of the lung. The influence of the mode of infusion (anterograde (AG): through the pulmonary artery (PA); retrograde (RG): through the pulmonary vein (PV)) on doxorubicin pharmacokinetics and lung distribution was unknown. Therefore, a simple, rapid and sensitive high-performance liquid chromatography method has been developed to quantify doxorubicin in four different biological matrices (infusion effluent, serum, tissues with low or high levels of doxorubicin). The related compound daunorubicin was used as internal standard (I.S.). Following a single-step protein precipitation of 500 microl samples with 250 microl acetone and 50 microl zinc sulfate 70% aqueous solution, the obtained supernatant was evaporated to dryness at 60 degrees C for exactly 45 min under a stream of nitrogen and the solid residue was solubilized in 200 microl of purified water. A 100 microl-volume was subjected to HPLC analysis onto a Nucleosil 100-5 microm C18 AB column equipped with a guard column (Nucleosil 100-5 microm C(6)H(5) (phenyl) end-capped) using a gradient elution of acetonitrile and 1-heptanesulfonic acid 0.2% pH 4: 15/85 at 0 min-->50/50 at 20 min-->100/0 at 22 min-->15/85 at 24 min-->15/85 at 26 min, delivered at 1 ml/min. The analytes were detected by fluorescence detection with excitation and emission wavelength set at 480 and 550 nm, respectively. The calibration curves were linear over the range of 2-1000 ng/ml for effluent and plasma matrices, and 0.1 microg/g-750 microg/g for tissues matrices. The method is precise with inter-day and intra-day relative standard deviation within 0.5 and 6.7% and accurate with inter-day and intra-day deviations between -5.4 and +7.7%. The in vitro stability in all matrices and in processed samples has been studied at -80 degrees C for 1 month, and at 4 degrees C for 48 h, respectively. During initial studies, heparin used as anticoagulant was found to profoundly influence the measurements of doxorubicin in effluents collected from animals under ILP. Moreover, the strong matrix effect observed with tissues samples indicate that it is mandatory to prepare doxorubicin calibration standard samples in biological matrices which would reflect at best the composition of samples to be analyzed. This method was successfully applied in animal studies for the analysis of effluent, serum and tissue samples collected from pigs and rats undergoing ILP.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The arenavirus Lassa virus (LASV) causes a severe haemorrhagic fever with high mortality in man. The cellular receptor for LASV is dystroglycan (DG). DG is a ubiquitous receptor for extracellular matrix (ECM) proteins, which cooperates with β1 integrins to control cell-matrix interactions. Here, we investigated whether LASV binding to DG triggers signal transduction, mimicking the natural ligands. Engagement of DG by LASV resulted in the recruitment of the adaptor protein Grb2 and the protein kinase MEK1 by the cytoplasmic domain of DG without activating the MEK/ERK pathway, indicating assembly of an inactive signalling complex. LASV binding to cells however affected the activation of the MEK/ERK pathway via α6β1 integrins. The virus-induced perturbation of α6β1 integrin signalling critically depended on high-affinity LASV binding to DG and DG's cytoplasmic domain, indicating that LASV-receptor binding perturbed signalling cross-talk between DG and β1 integrins.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Four standard radiation qualities (from RQA 3 to RQA 9) were used to compare the imaging performance of a computed radiography (CR) system (general purpose and high resolution phosphor plates of a Kodak CR 9000 system), a selenium-based direct flat panel detector (Kodak Direct View DR 9000), and a conventional screen-film system (Kodak T-MAT L/RA film with a 3M Trimax Regular screen of speed 400) in conventional radiography. Reference exposure levels were chosen according to the manufacturer's recommendations to be representative of clinical practice (exposure index of 1700 for digital systems and a film optical density of 1.4). With the exception of the RQA 3 beam quality, the exposure levels needed to produce a mean digital signal of 1700 were higher than those needed to obtain a mean film optical density of 1.4. In spite of intense developments in the field of digital detectors, screen-film systems are still very efficient detectors for most of the beam qualities used in radiology. An important outcome of this study is the behavior of the detective quantum efficiency of the digital radiography (DR) system as a function of beam energy. The practice of users to increase beam energy when switching from a screen-film system to a CR system, in order to improve the compromise between patient dose and image quality, might not be appropriate when switching from screen-film to selenium-based DR systems.