789 resultados para Coagulation-floculation
Resumo:
Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury. It is a response to various diseases of variable etiology, including SARS-CoV infection. To date, a comprehensive study of the genomic physiopathology of ARDS (and SARS) is lacking, primarily due to the difficulty of finding suitable materials to study the disease process at a tissue level (instead of blood, sputa or swaps). Hereby we attempt to provide such study by analyzing autopsy lung samples from patient who died of SARS and showed different degrees of severity of the pulmonary involvement. We performed real-time quantitative PCR analysis of 107 genes with functional roles in inflammation, coagulation, fibrosis and apoptosis: some key genes were confirmed at a protein expression level by immunohistochemistry and correlated to the degree of morphological severity present in the individual samples analyzed. Significant expression levels were identified for ANPEP (a receptor for CoV), as well as inhibition of the STAT1 pathway, IFNs production and CXCL10 (a T-cell recruiter). Other genes unassociated to date with ARDS/SARS include C1Qb, C5R1, CASP3, CASP9, CD14, CD68, FGF7, HLA-DRA, ICF1, IRF3, MALAT-1, MSR1, NFIL3, SLPI, USP33, CLC, GBP1 and TACI. As a result, we proposed to therapeutically target some of these genes with compounds such as ANPEP inhibitors, SLPI and dexamethasone. Ultimately, this study may serve as a model for future, tissue-based analyses of fibroinflammatory conditions affecting the lung. (C) 2009 Elsevier B.V. All rights reserved.
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The impact of age upon therapeutic response to unfractionated heparin (UFH) in children is proposed to reflect quantitative and potentially qualitative differences in coagulation proteins across childhood. This study explores the UFH-dependent tissue factor pathway inhibitor (TFPI) release in children compared to previously published data in adults. Children <16 years of age undergoing cardiac angiography formed the population for this prospective cohort study. TFPI release was measured prior to (baseline) and at 15, 30, 45 and 120 min post-UFH dose. This study demonstrated that, whilst the immediate release of TFPI post-UFH was similar in children compared to adults, TFPI release in children remained increased and consistent for a significantly longer period post-UFH administration compared to adults. Plasma TFPI levels in children did not demonstrate an UFH concentration –dependent reduction, as has been previously reported in adults. The prolonged TFPI-mediated anticoagulant levels observed in children administered UFH may contribute to the increased rate of major bleeding reported in children compared to adults. Furthermore, we postulate that this sustained UFH-dependent increase in TFPI levels in children may influence the binding of UFH to competitive plasma proteins, such as those involved in the immunological response to UFH associated with heparin-induced thrombocytopenia.
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C-type lectin-like proteins (CTLPs) isolated from snake venoms are the largest and most complex non-mammalian vertebrate C-type lectin-like domain family. In the present study, we simultaneously amplified four cDNAs encoding different types of CTLP subunits from the venoms of two different species of snakes by RT-PCR with a single sense primer and a nested universal primer - two CTLP subunit-encoding cDNAs were cloned from Deinagkistrodon acutus venom and two from Agkistrodon halys Pallas venom. All four cloned CTLP subunits exhibited typical motifs in their corresponding domain regions but with relatively-low sequence similarities to each other. Compared with previously-published CTLPs, the four cloned CTLPs subunits showed slight variations in the calcium-binding sites and the disulphide bonding patterns. To our knowledge, these data constitute the first example of co-expression of CTLP platelet glycoprotein Ib-binding subunits and coagulation factors in Agkistrodon halys Pallas venom.
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One novel Kunitz BPTI-like peptide designated as BBPTI-1, with chymotrypsin inhibitory activity was identified from the venom of Burmese Daboia russelii siamensis. It was purified by three steps of chromatography including gel filtration, cation exchange and reversed phase. A partial N-terminal sequence of BBPTI-1, HDRPKFCYLPADPGECLAHMRSF was obtained by automated Edman degradation and a Ki value of 4.77. nM determined. Cloning of BBPTI-1 including the open reading frame and 3' untranslated region was achieved from cDNA libraries derived from lyophilized venom using a 3' RACE strategy. In addition a cDNA sequence, designated as BBPTI-5, was also obtained. Alignment of cDNA sequences showed that BBPTI-5 exhibited an identical sequence to BBPTI-1 cDNA except for an eight nucleotide deletion in the open reading frame. Gene variations that represented deletions in the BBPTI-5 cDNA resulted in a novel protease inhibitor analog. Amino acid sequence alignment revealed that deduced peptides derived from cloning of their respective precursor cDNAs from libraries showed high similarity and homology with other Kunitz BPTI proteinase inhibitors. BBPTI-1 and BBPTI-5 consist of 60 and 66 amino acid residues respectively, including six conserved cysteine residues. As these peptides have been reported to have influence on the processes of coagulation, fibrinolysis and inflammation, their potential application in biomedical contexts warrants further investigation. © 2013 Elsevier Inc.
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Various parameters of coagulation and fibrinolysis were measured in 13 men (aged 54 +/- 3 yr) with non-insulin-dependent diabetes mellitus (NIDDM) before and after 12-14 wk of exercise training. Subjects exercised for 30 min 3 times/wk at 70% of maximum O2 consumption (VO2max). Training increased VO2max by 12.5% but did not alter body weight, relative body fat, blood pressure, cholesterol, triglycerides, or high-density lipoprotein cholesterol. Slight downward trends were apparent for fasting glucose and insulin, but glycosylated hemoglobin was unchanged. There were no changes in coagulation parameters of plasminogen, hematocrit, or alpha 2-antiplasmin. Plasma fibrinogen (303 +/- 24.2 vs. 256 +/- 12.3 mg/dl) and fibronectin (380 +/- 41.9 vs. 301 +/- 22.2 micrograms/ml) were significantly reduced (P less than 0.02) by exercise conditioning. Three assays of fibrinolytic activity (tissue plasminogen activator, euglobulin lysis time, and an isotopic measure of fibrinolysis) confirmed that neither basal fibrinolysis nor the fibrinolytic responses to venous occlusion and maximal exercise were significantly altered. Exercise conditioning may have antithrombotic effects in NIDDM by reducing plasma fibrinogen and fibronectin. Although the significance of the fall in fibronectin awaits further studies, the reduction in plasma fibrinogen gives a rationale for the use of exercise training in men with NIDDM.
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BACKGROUND: There have been few histological or ultrastructural studies of the outer retina and choriocapillaris following panretinal photocoagulation therapy. This investigation examines the long-term morphological effects of panretinal photocoagulation in two patients with type II diabetes who had received laser treatment more than 6 months prior to death.
METHODS: Regions of retina and choroid from each patient were fixed in 2.5% glutaraldehyde, dissected out and examined using light microscopy and scanning and transmission electron microscopy.
RESULTS: After removing the neural retina, scanning electron microscopy of non-photocoagulated areas of the eye cups revealed normal cobblestone-like retinal pigment epithelial (RPE) cells. Regions with laser scars showed little RPE infiltration into the scar area, although large rounded cells often appeared in isolation within these areas. Sections of the retina and choroid in burn regions showed a complete absence of the outer nuclear layer and photoreceptor cells, with the inner retinal layers lying in close apposition to Bruch's membrane. Non-photocoagulated regions of the retina and choroid appeared normal in terms of both cell number and cell distribution. The RPE layer was absent within burn scars but many RPE-like cells appeared markedly hypertrophic at the edges of these regions. Bruch's membrane always remained intact, although the underlying choriocapillaris was clearly disrupted at the point of photocoagulation burns, appearing largely fibrosed and non-perfused. Occasional choroidal capillaries occurring in this region were typically small in profile and had plump non-fenestrated endothelium.
CONCLUSIONS: This study outlines retinal and choroidal cell responses to panretinal photocoagulation in diabetic patients and demonstrates an apparent reduction in the capacity of these tissues to repair laser damage.
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We induced choroidal neovascularization in the rhesus monkey by impoverishing the blood supply to the inner retina and producing defects in Bruch's membrane by photocoagulation. Fourteen of 46 eyes undergoing photocoagulation developed neovascular fronds which were identified and categorized by histopathologic examination and fluorescein angiography. All new vessels gained access to the retina through defects in Bruch's membrane at the site of photocoagulation marks. In eight eyes the new vessels remained localized to the immediate vicinity of photocoagulation marks. In four eyes neovascular fronds infiltrated the subretinal space for distances up to 6 disk diameters from the point of entry into the retina. In the two eyes choroidovitreal neovascular complexes developed but rapidly regressed shortly after gaining the vitreous cavity. Fluorescein angiography demonstrated that all neovascular fronds were grossly incompetent to dye but that formed feeding channels had some degree of integrity. Light microscopic studies showed the proliferating networks to be composed of capillaries with well-formed basement membranes and more mature vessels with the basic structure of choroidal arteries and veins.
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Background: A relationship may exist between body iron stores, endothelial dysfunction and overall cardiovascular risk.
Aims: To compare vascular compliance, biochemical endothelial function and antioxidant status between patients with homozygous hereditary haemochromatosis and healthy controls.
Methods: Haemochromatosis patients and healthy controls were recruited. Measures of vascular compliance were assessed by applanation tonometry. Serological markers of endothelial function (plasma lipid hydroperoxides, cell adhesion molecules), antioxidant levels (ascorbate, lipid soluble antioxidants) and high-sensitivity C-reactive protein (CRP) were also measured.
Results: Thirty-five hereditary haemochromatosis patients (ten females, mean age 54.6) and 36 controls (27 female, mean age 54.0) were recruited. Haemochromatosis patients had significantly higher systolic and diastolic blood pressures. Pulse wave velocity (PWV) was significantly higher in male haemochromatosis patients (9.90 vs. 8.65 m/s, p = 0.048). Following adjustment for age and blood pressure, male haemochromatosis patients continued to have a trend for higher PWVs (+1.37 m/s, p = 0.058). Haemochromatosis patients had significantly lower levels of ascorbate (46.11 vs. 72.68 lmol/L, p = 0.011), retinol (1.17 vs. 1.81 lmol/L, p = 0.001) and g-tocopherol (2.51 vs. 3.14 lmol/L, p = 0.011). However, there was no difference in lipid hydroperoxides (0.46 vs. 0.47 nmol/L, p = 0.94), cell adhesion molecule levels (ICAM: 348.12 vs. 308.03 ng/mL, p = 0.32 and VCAM: 472.78 vs. 461.31 ng/mL, p = 0.79) or high-sensitivity CRP (225.01 vs. 207.13 mg/L, p = 0.32).
Conclusions: Haemochromatosis is associated with higher PWVs in males and diminished antioxidants across the sexes but no evidence of endothelial dysfunction or increased lipid peroxidation.
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Introduction: Juvenile idiopathic arthritis (JIA) is the most common rheumatological disease of childhood with a prevalence of around 1 in 1000. Without appropriate treatment it can have devastating consequences including permanent disability from joint destruction and growth deformities. Disease aetiology remains unknown. Investigation of disease pathology at the level of the synovial membrane is required if we want to begin to understand the disease at the molecular and biochemical level. The synovial membrane proteome from early disease-stage, treatment naive JIA patients was compared between polyarticular and oligoarticular subgroups.
Methods: Protein was extracted from 15 newly diagnosed, treatment naive JIA synovial membrane biopsies and separated by two dimensional fluorescent difference in-gel electrophoresis. Proteins displaying a two-fold or greater change in expression levels between the two subgroups were identified by matrix assisted laser desorption ionization-time of flight mass spectrometry with expression further verified by Western blotting and immunohistochemistry.
Results: Analysis of variance analysis (P <= 0.05) revealed 25 protein spots with a two-fold or greater difference in expression levels between polyarticular and oligoarticular patients. Hierarchical cluster analysis with Pearson ranked correlation revealed two distinctive clusters of proteins. Some of the proteins that were differentially expressed included: integrin alpha 2b (P = 0.04); fibrinogen D fragment (P =0.005); collagen type VI (P = 0.03); fibrinogen gamma chain (P = 0.05) and peroxiredoxin 2 (P = 0.02). The identified proteins are involved in a number of different processes including platelet activation and the coagulation system.
Conclusions: The data indicates distinct synovial membrane proteome profiles between JIA subgroups at an early stage in the disease process. The identified proteins also provide insight into differentially perturbed pathways which could influence pathological events at the joint level.
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Context. Protoplanetary disks are vital objects in star and planet formation, possessing all the material, gas and dust, which may form a planetary system orbiting the new star. Small, simple molecules have traditionally been detected in protoplanetary disks; however, in the ALMA era, we expect the molecular inventory of protoplanetary disks to significantly increase.
Aims. We investigate the synthesis of complex organic molecules (COMs) in protoplanetary disks to put constraints on the achievable chemical complexity and to predict species and transitions which may be observable with ALMA.
Methods. We have coupled a 2D steady-state physical model of a protoplanetary disk around a typical T Tauri star with a large gas-grain chemical network including COMs. We compare the resulting column densities with those derived from observations and perform ray-tracing calculations to predict line spectra. We compare the synthesised line intensities with current observations and determine those COMs which may be observable in nearby objects. We also compare the predicted grain-surface abundances with those derived from cometary comae observations.
Results. We find COMs are efficiently formed in the disk midplane via grain-surface chemical reactions, reaching peak grain-surface fractional abundances similar to 10(-6)-10(-4) that of the H nuclei number density. COMs formed on grain surfaces are returned to the gas phase via non-thermal desorption; however, gas-phase species reach lower fractional abundances than their grain-surface equivalents, similar to 10(-12)-10(-7). Including the irradiation of grain mantle material helps build further complexity in the ice through the replenishment of grain-surface radicals which take part in further grain-surface reactions. There is reasonable agreement with several line transitions of H2CO observed towards T Tauri star-disk systems. There is poor agreement with HC3(N) lines observed towards LkCa 15 and GO Tau and we discuss possible explanations for these discrepancies. The synthesised line intensities for CH3OH are consistent with upper limits determined towards all sources. Our models suggest CH3OH should be readily observable in nearby protoplanetary disks with ALMA; however, detection of more complex species may prove challenging, even with ALMA "Full Science" capabilities. Our grain-surface abundances are consistent with those derived from cometary comae observations providing additional evidence for the hypothesis that comets (and other planetesimals) formed via the coagulation of icy grains in the Sun's natal disk.
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Dissolved Air Flotation (DAF) is a well-known coagulation-flotation system applied at large scale for microalgae harvesting. Compared to conventional harvesting technologies DAF allows high cell recovery at lower energy demand. By replacing microbubbles with microspheres, the innovative Ballasted Dissolved Air Flotation (BDAF) technique has been reported to achieve the same algae cell removal efficiency, while saving up to 80% of the energy required for the conventional DAF unit. Using three different algae cultures (Scenedesmus obliquus, Chlorella vulgaris and Arthrospira maxima), the present work investigated the practical, economic and environmental advantages of the BDAF system compared to the DAF system. 99% cells separation was achieved with both systems, nevertheless, the BDAF technology allowed up to 95% coagulant reduction depending on the algae species and the pH conditions adopted. In terms of floc structure and strength, the inclusion of microspheres in the algae floc generated a looser aggregate, showing a more compact structure within single cell alga, than large and filamentous cells. Overall, BDAF appeared to be a more reliable and sustainable harvesting system than DAF, as it allowed equal cells recovery reducing energy inputs, coagulant demand and carbon emissions. © 2014 Elsevier Ltd.
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Growth-promoting agents are continually misused for increasing animal growth and fraudulent gain in the meat industry, yet detection rates from conventional targeted testing for drug residues do not reflect this. This is because testing currently relies on direct detection of drugs or related metabolites and administrators of such compounds can take adaptive measures to avoid detection through the use of endogenous or unknown drugs, and low dose or combined mixtures. New detection methods are needed which focus on the screening of biological responses of an animal to such growth-promoting agents as it has been demonstrated that genomic, proteomic and metabolomics profiles are altered by xenobiotic intake. Therefore, an untargeted proteomics approach using comparative two-dimensional gel electrophoresis (2DE) was carried out to identify putative proteins altered in plasma after treatment with oestradiol, dexamethasone or prednisolone. Twenty-four male cattle were randomly assigned to four groups (n = 6) for experimental treatment over 40 days, namely a control group of non-treated cattle, and three groups administered 17β-oestradiol-3-benzoate (0.01 mg/kg, intramuscular), dexamethasone sodium phosphate (0.7 mg/day, per os) or prednisolone acetate (15 mg/day, per os), respectively. Plasma collected from each animal at day 25 post study initiation was subjected to proteomic analysis by 2DE for comparison of protein expression between treated and untreated animals. Analysis of acquired gel images revealed 22 plasma proteins which differed in expression by more than 50 % (p < 0.05) in treated animals compared to untreated animals. Proteins of interest underwent identification by LC–MS/MS analysis and were found to have associated roles in transport, blood coagulation, immune response and metabolism pathways. In this way, seven proteins are highlighted as novel biomarker candidates including transthyretin which is shown to be significantly increased in all treatment groups compared to control animals and potentially may find use as global markers of suspect anabolic practice.