101 resultados para Fibrin clot


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A 10-year-old, entire, male, mixed-breed dog was presented for severe haematuria and stranguria. Ultrasound revealed a large intraluminal urinary bladder blood clot and a prostatic space-occupying lesion. Invasion of the lesion into the prostatic urethra was detected ultrasonographically during compression of the urinary bladder. Post-mortem examination revealed primary prostatic haemangiosarcoma infiltrating the urethra. Haemangiosarcoma should be considered as a rare cause of prostatic mass lesions, haematuria or lower urinary tract signs in dogs.

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PURPOSE: To demonstrate the feasibility of direct angioscopic visualization of an optional inferior vena cava (IVC) filter in situ and during retrieval. MATERIALS AND METHODS: Angioscopy was used for direct visualization of optional IVC filters in six sheep. Cavograms were obtained before the filters were retrieved. After successful filter retrieval, segmental IVC perfusion was performed to evaluate filter retrieval-related damage to the IVC wall. Therefore, all branch vessels were ligated before the IVC segment was flushed with normal saline solution until it was fully distended. Then, the inflow was terminated and the IVC segment observed for deflation. Subsequently, the IVC was harvested en bloc, dissected, and inspected macroscopically. RESULTS: The visibility of IVC filters at angioscopy was excellent. During the retrieval procedure, filter collapse and retraction into the sheath were clearly demonstrated. Angioscopy provided additional information to that obtained with cavography, demonstrating adherent material in three filters. Three filters in place for more than 2 months could not be retrieved because the filter legs were incorporated into the IVC wall. After filter retrieval, there was no perforation at segmental IVC perfusion. At macroscopic inspection of the IVC lumen, a small piece of detached endothelium was found in one animal. CONCLUSION: Angioscopy enabled the direct evaluation of optional IVC filters in situ and during retrieval. Compared with cavography, angioscopy provided additional information about the filter in situ and the retrieval procedure. Future applications of this technique could include studies of filter migration, compression, and clot-trapping efficacy.

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INTRODUCTION: Thrombotic events are a common and severe complication of endovascular aneurysm treatment with significant impact on patients' outcome. This study evaluates risk factors for thrombus formation and assesses the efficacy and safety of abciximab for clot dissolution. MATERIALS AND METHODS: All patients treated with abciximab during (41 patients) or shortly after (22 patients) intracranial aneurysm coil embolisation were retrieved from the institutional database (2000 to 2007, 1,250 patients). Sixty-three patients (mean age, 55.3 years, +/-12.8) had received either intra-arterial or intravenous abciximab. Risk factors for clot formation were assessed and the angiographic and clinical outcome evaluated. RESULTS: No aneurysm rupture occurred during or after abciximab application. The intra-procedural rate of total recanalisation was 68.3%. Thromboembolic complications were frequently found in aneurysms of the Acom complex and of the basilar artery, whilst internal carotid artery aneurysms were underrepresented. Two patients died of treatment-related intracranial haemorrhages into preexisting cerebral infarcts. Two patients developed a symptomatic groin haematoma. CONCLUSIONS: Abciximab is efficacious and safe for thrombolysis during and after endovascular intracranial aneurysm treatment in the absence of preexisting ischaemic stroke.

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Tissue engineering represents an attractive approach for the treatment of congestive heart failure. The influence of the differentiation of myogenic graft for functional recovery is not defined. We engineered a biodegradable skeletal muscle graft (ESMG) tissue and investigated its functional effect after implantation on the epicardium of an infarcted heart segment. ESMGs were synthesized by mixing collagen (2 mg/mL), Matrigel (2 mg/mL), and rat skeletal muscle cells (10(6)). Qualitative and quantitative aspects of ESMGs were optimized. Two weeks following coronary ligation, the animals were randomized in three groups: ESMG glued to the epicardial surface with fibrin (ESMG, n = 7), fibrin alone (fibrin, n = 5), or sham operation (sham, n = 4). Echocardiography, histology, and immunostaining were performed 4 weeks later. A cohesive three-dimensional tissular structure formed in vitro within 1 week. Myoblasts differentiated into randomly oriented myotubes. Four weeks postimplantation, ESMGs were vascularized and invaded by granulation tissue. Mean fractional shortening (FS) was, however, significantly increased in the ESMG group as compared with preimplantation values (42 +/- 6 vs. 33 +/- 5%, P < 0.05) and reached the values of controlled noninfarcted animals (control, n = 5; 45 +/- 3%; not significant). Pre- and postimplantation FS did not change over these 4 weeks in the sham group and the fibrin-treated animals. This study showed that it is possible to improve systolic heart function following myocardial infarction through implantation of differentiated muscle fibers seeded on a gel-type scaffold despite a low rate of survival.

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OBJECTIVE: To compare the risk of shunt-dependent hydrocephalus after treatment of ruptured intracranial aneurysms by clipping versus coiling. METHODS: We analyzed 596 patients prospectively added to our database from July of 1999 to November of 2005 concerning the risk of shunt dependency after clipping versus coiling. Factors analyzed included age; sex; Hunt and Hess grade; Fisher grade; acute hydrocephalus; intraventricular hemorrhage; angiographic vasospasm; and number, size, and location of aneurysms. In addition, a meta-analysis of available data from the literature was performed identifying four studies with quantitative data on the frequency of clip, coil, and shunt dependency. RESULTS: The institutional series revealed Hunt and Hess grade, Fisher grade, acute hydrocephalus, intraventricular hemorrhage, and angiographic vasospasm as significant (P < 0.05) risk factors for shunt dependency after a univariate analysis. In a multivariate logistic regression analysis, we isolated intraventricular hemorrhage, acute hydrocephalus, and angiographic vasospasm as independent, significant risk factors for shunt dependency. The meta-analysis, including the current data, revealed a significantly higher risk for shunt dependency after coiling than after clipping (P = 0.01). CONCLUSION: Clipping of a ruptured aneurysm may be associated with a lower risk for developing shunt dependency, possibly by clot removal. This might influence long-term outcome and surgical decision making.

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Intra-alveolar fibrin is formed following lung injury and inflammation and may contribute to the development of pulmonary fibrosis. Fibrin turnover is altered in patients with pulmonary fibrosis, resulting in intra-alveolar fibrin accumulation, mainly due to decreased fibrinolysis. Alveolar type II epithelial cells (AEC) repair the injured alveolar epithelium by migrating over the provisional fibrin matrix. We hypothesized that repairing alveolar epithelial cells modulate the underlying fibrin matrix by release of fibrinolytic activity, and that the degree of fibrinolysis modulates alveolar epithelial repair on fibrin. To test this hypothesis we studied alveolar epithelial wound repair in vitro using a modified epithelial wound repair model with human A549 alveolar epithelial cells cultured on a fibrin matrix. In presence of the inflammatory cytokine interleukin-1beta, wounds increase by 800% in 24 hours mainly due to detachment of the cells, whereas in serum-free medium wound areas decreases by 22.4 +/- 5.2% (p < 0.01). Increased levels of D-dimer, FDP and uPA in the cell supernatant of IL-1beta-stimulated A549 epithelial cells indicate activation of fibrinolysis by activation of the plasmin system. In presence of low concentrations of fibrinolysis inhibitors, including specific blocking anti-uPA antibodies, alveolar epithelial repair in vitro was improved, whereas in presence of high concentrations of fibrinolysis inhibitors, a decrease was observed mainly due to decreased spreading and migration of cells. These findings suggest the existence of a fibrinolytic optimum at which alveolar epithelial repair in vitro is most efficient. In conclusion, uPA released by AEC alters alveolar epithelial repair in vitro by modulating the underlying fibrin matrix.

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BACKGROUND: Potentized antimony is traditionally used in anthroposophic medicine to enhance hemostasis in bleeding disorders, but evidence of its effectiveness is scarce. On the other hand, non-toxic and economic additional therapeutic options for hemostatic disorders are desirable. OBJECTIVES: We examined all available literature on the subject and performed a controlled pilot in vitro study to test the procoagulatory potency of antimony D 5. DESIGN: Freshly drawn citrated whole blood of 12 healthy volunteers and 12 patients with bleeding disorders was equally distributed into 344 portions, after which it was mixed with antimony D 5, or its potentized vehicle (lactose D 5) as control solution and tested with thrombelastography. The paired t-test and the Wilcoxon signed rank test were used for statistical analysis. In 5 of the 12 healthy donors, a second blood sample was drawn to assess individual variability and increase the total number of replicates. Thus three separate calculations were performed: for the 12 patients, the 12 healthy donors, and the 5 later samples from the same donors. The analysis was exploratory, and no Bonferroni correction was applied. RESULTS: In the antimony D5 samples of the 12 healthy subjects, but not the patients, there was a tendency toward a shorter clotting time (CT) (p = 0.074) and a trend for an increased clot firmness, expressed as maximal amplitude (MA) (p = 0.058). The increase of MA was significant (p = 0.011) when the later samples were included. No statistical difference was detected for the clot formation time and the clot lysis index. CONCLUSION: The exploratory results of this pilot study are inconclusive as to whether antimony D5 has a procoagulatory effect in vitro, although the results suggest an effect on MA and possibly CT. More research is warranted.

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BACKGROUND: This study analyzes the effects on coagulation and fibrinolysis comparing off-pump coronary artery bypass (OPCAB) and on-pump CABG operations. METHODS: In a prospective, nonrandomized, comparative evaluation, patients scheduled for elective myocardial revascularization were studied. Due to possible confounding factors patients with postoperative retransfusion of mediastinal shed blood were excluded. Nine patients underwent OPCAB operation and 16 underwent on-pump CABG. Activated clotting time (ACT) was adjusted to 250 seconds in OPCAB (81 +/- 18 [mean +/- SD] IU/kg heparin) and to more than 480 seconds in on-pump CABG (400 IU/kg heparin, additional 10,000 IU in pump prime). Perioperatively blood samples were collected and hematologic and hemostatic variables including fibrinopeptide A (FPA), fibrin monomer (FM), thrombin-antithrombin complex (TAT), and D-dimer were analyzed. RESULTS: Both groups showed comparable demographic variables. Number of grafts per patient was slightly higher in the on-pump group (3.6 +/- 0.6 versus 3.0 +/- 1.1, p = 0.23). The FPA levels did not differ significantly between the groups. The FM, TAT, and D-dimer values were significantly higher in on-pump CABG (p < 0.0001, p < 0.01, and p < 0.0001, respectively), reflecting increased coagulant and fibrinolytic activity. This was also the case when values were corrected for hemodilution. CONCLUSIONS: Despite lower systemic anticoagulation activation of coagulation and fibrinolysis is reduced in OPCAB compared with on-pump CABG. Reduced thrombin generation and reduced fibrinolytic activity in OPCAB indicates better preservation of hemostasis. We suggest the term "preserved hemostasis" instead of "hypercoagulant activity" with respect to OPCAB.

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OBJECT: Ultrasound may be a reliable but simpler alternative to intraoperative MR imaging (iMR imaging) for tumor resection control. However, its reliability in the detection of tumor remnants has not been definitely proven. The aim of the study was to compare high-field iMR imaging (1.5 T) and high-resolution 2D ultrasound in terms of tumor resection control. METHODS: A prospective comparative study of 26 consecutive patients was performed. The following parameters were compared: the existence of tumor remnants after presumed radical removal and the quality of the images. Tumor remnants were categorized as: detectable with both imaging modalities or visible only with 1 modality. RESULTS: Tumor remnants were detected in 21 cases (80.8%) with iMR imaging. All large remnants were demonstrated with both modalities, and their image quality was good. Two-dimensional ultrasound was not as effective in detecting remnants<1 cm. Two remnants detected with iMR imaging were missed by ultrasound. In 2 cases suspicious signals visible only on ultrasound images were misinterpreted as remnants but turned out to be a blood clot and peritumoral parenchyma. The average time for acquisition of an ultrasound image was 2 minutes, whereas that for an iMR image was approximately 10 minutes. Neither modality resulted in any procedure-related complications or morbidity. CONCLUSIONS: Intraoperative MR imaging is more precise in detecting small tumor remnants than 2D ultrasound. Nevertheless, the latter may be used as a less expensive and less time-consuming alternative that provides almost real-time feedback information. Its accuracy is highest in case of more confined, deeply located remnants. In cases of more superficially located remnants, its role is more limited.

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INTRODUCTION: The inflammatory response to an invading pathogen in sepsis leads to complex alterations in hemostasis by dysregulation of procoagulant and anticoagulant factors. Recent treatment options to correct these abnormalities in patients with sepsis and organ dysfunction have yielded conflicting results. Using thromboelastometry (ROTEM(R)), we assessed the course of hemostatic alterations in patients with sepsis and related these alterations to the severity of organ dysfunction. METHODS: This prospective cohort study included 30 consecutive critically ill patients with sepsis admitted to a 30-bed multidisciplinary intensive care unit (ICU). Hemostasis was analyzed with routine clotting tests as well as thromboelastometry every 12 hours for the first 48 hours, and at discharge from the ICU. Organ dysfunction was quantified using the Sequential Organ Failure Assessment (SOFA) score. RESULTS: Simplified Acute Physiology Score II and SOFA scores at ICU admission were 52 +/- 15 and 9 +/- 4, respectively. During the ICU stay the clotting time decreased from 65 +/- 8 seconds to 57 +/- 5 seconds (P = 0.021) and clot formation time (CFT) from 97 +/- 63 seconds to 63 +/- 31 seconds (P = 0.017), whereas maximal clot firmness (MCF) increased from 62 +/- 11 mm to 67 +/- 9 mm (P = 0.035). Classification by SOFA score revealed that CFT was slower (P = 0.017) and MCF weaker (P = 0.005) in patients with more severe organ failure (SOFA >or= 10, CFT 125 +/- 76 seconds, and MCF 57 +/- 11 mm) as compared with patients who had lower SOFA scores (SOFA <10, CFT 69 +/- 27, and MCF 68 +/- 8). Along with increasing coagulation factor activity, the initially increased International Normalized Ratio (INR) and prolonged activated partial thromboplastin time (aPTT) corrected over time. CONCLUSIONS: Key variables of ROTEM(R) remained within the reference ranges during the phase of critical illness in this cohort of patients with severe sepsis and septic shock without bleeding complications. Improved organ dysfunction upon discharge from the ICU was associated with shortened coagulation time, accelerated clot formation, and increased firmness of the formed blood clot when compared with values on admission. With increased severity of illness, changes of ROTEM(R) variables were more pronounced.

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Advanced glycation end products (AGEs) may play a role in the pathogenesis of diabetic nephropathy, by modulating extracellular matrix turnover. AGEs are known to activate specific membrane receptors, including the receptor for AGE (RAGE). In the present study, we analyzed the various receptors for AGEs expressed by human mesangial cells and we studied the effects of glycated albumin and of carboxymethyl lysine on matrix protein and remodelling enzyme synthesis. Membrane RAGE expression was confirmed by FACS analysis. Microarray methods, RT-PCR, and Northern blot analysis were used to detect and confirm specific gene induction. Zymographic analysis and ELISA were used to measure the induction of tPA and PAI-1. We show herein that cultured human mesangial cells express AGE receptor type 1, type 2 and type 3 and RAGE. AGEs (200 microg/ml) induced at least a 2-fold increase in mRNA for 10 genes involved in ECM remodelling, including tPA, PAI-1 and TIMP-3. The increase in tPA synthesis was confirmed by fibrin zymography. The stimulation of PAI-1 synthesis was confirmed by ELISA. AGEs increased PAI-1 mRNA through a signalling pathway involving reactive oxygen species, the MAP kinases ERK-1/ERK-2 and the nuclear transcription factor NF-kappaB, but not AP-1. Carboxymethyl lysine (CML, 5 microM), which is a RAGE ligand, also stimulated PAI-1 synthesis by mesangial cells. In addition, a blocking anti-RAGE antibody partially inhibited the AGE-stimulated gene expression and decreased the PAI-1 accumulation induced by AGEs and by CML. Inhibition of AGE receptors or neutralization of the protease inhibitors TIMP-3 and PAI-1 could represent an important new therapeutic strategy for diabetic nephropathy.

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INTRODUCTION Vasospastic brain infarction is a devastating complication of aneurysmal subarachnoid hemorrhage (SAH). Using a probe for invasive monitoring of brain tissue oxygenation or blood flow is highly focal and may miss the site of cerebral vasospasm (CVS). Probe placement is based on the assumption that the spasm will occur either at the dependent vessel territory of the parent artery of the ruptured aneurysm or at the artery exposed to the focal thick blood clot. We investigated the likelihood of a focal monitoring sensor being placed in vasospasm or infarction territory on a hypothetical basis. METHODS From our database we retrospectively selected consecutive SAH patients with angiographically proven (day 7-14) severe CVS (narrowing of vessel lumen >50%). Depending on the aneurysm location we applied a standard protocol of probe placement to detect the most probable site of severe CVS or infarction. We analyzed whether the placement was congruent with existing CVS/infarction. RESULTS We analyzed 100 patients after SAH caused by aneurysms located in the following locations: MCA (n = 14), ICA (n = 30), A1CA (n = 4), AcoA or A2CA (n = 33), and VBA (n = 19). Sensor location corresponded with CVS territory in 93% of MCA, 87% of ICA, 76% of AcoA or A2CA, but only 50% of A1CA and 42% of VBA aneurysms. The focal probe was located inside the infarction territory in 95% of ICA, 89% of MCA, 78% of ACoA or A2CA, 50% of A1CA and 23% of VBA aneurysms. CONCLUSION The probability that a single focal probe will be situated in the territory of severe CVS and infarction varies. It seems to be reasonably accurate for MCA and ICA aneurysms, but not for ACA or VBA aneurysms.

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BACKGROUND Overlapping first generation sirolimus- and paclitaxel-eluting stents are associated with persistent inflammation, fibrin deposition and delayed endothelialisation in preclinical models, and adverse angiographic and clinical outcomes--including death and myocardial infarction (MI)--in clinical studies. OBJECTIVES To establish as to whether there are any safety concerns with newer generation drug-eluting stents (DES). DESIGN Propensity score adjustment of baseline anatomical and clinical characteristics were used to compare clinical outcomes (Kaplan-Meier estimates) between patients implanted with overlapping DES (Resolute zotarolimus-eluting stent (R-ZES) or R-ZES/other DES) against no overlapping DES. Additionally, angiographic outcomes for overlapping R-ZES and everolimus-eluting stents were evaluated in the randomised RESOLUTE All-Comers Trial. SETTING Patient level data from five controlled studies of the RESOLUTE Global Clinical Program evaluating the R-ZES were pooled. Enrollment criteria were generally unrestrictive. PATIENTS 5130 patients. MAIN OUTCOME MEASURES 2-year clinical outcomes and 13-month angiographic outcomes. RESULTS 644 of 5130 patients (12.6%) in the RESOLUTE Global Clinical Program underwent overlapping DES implantation. Implantation of overlapping DES was associated with an increased frequency of MI and more complex/calcified lesion types at baseline. Adjusted in-hospital, 30-day and 2-year clinical outcomes indicated comparable cardiac death (2-year overlap vs non-overlap: 3.0% vs 2.1%, p=0.36), major adverse cardiac events (13.3% vs 10.7%, p=0.19), target-vessel MI (3.9% vs 3.4%, p=0.40), clinically driven target vessel revascularisation (7.7% vs 6.5%, p=0.32), and definite/probable stent thrombosis (1.4% vs 0.9%, p=0.28). 13-month adjusted angiographic outcomes were comparable between overlapping and non-overlapping DES. CONCLUSIONS Overlapping newer generation DES are safe and effective, with comparable angiographic and clinical outcomes--including repeat revascularisation--to non-overlapping DES.

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Growing evidence suggests a prominent role of the complement system in the pathogenesis of cardio- and cerebrovascular diseases (CVD). Mannan-binding lectin-associated serine proteases (MASPs) MASP-1 and MASP-2 of the complement lectin pathway contribute to clot formation and may represent an important link between inflammation and thrombosis. MBL-associated protein MAp44 has shown cardioprotective effects in murine models. However, MAp44 has never been measured in patients with CVD and data on MASP levels in CVD are scarce. Our aim was to investigate for the first time plasma levels of MAp44 and MASP-1, -2, -3 concomitantly in patients with CVD. We performed a pilot study in 50 healthy volunteers, in stable coronary artery disease (CAD) patients with one-vessel (n = 51) or three-vessel disease (n = 53) and age-matched controls with normal coronary arteries (n = 53), 49 patients after myocardial infarction (MI) and 66 patients with acute ischaemic stroke. We measured MAp44 and MASP-1 levels by in-house time-resolved immunofluorometric assays. MASP-2 and MASP-3 levels were measured using commercial enzyme-linked immunosorbent assay kits. MASP-1 levels were highest in subacute MI patients and lowest in acute stroke patients. MASP-2 levels were lower in MI and stroke patients compared with controls and CAD patients. MASP-3 and MAp44 levels did not differ between groups. MASP or MAp44 levels were not associated with severity of disease. MASP and MAp44 levels were associated with cardiovascular risk factors including dyslipidaemia, obesity and hypertension. Our results suggest that MASP levels may be altered in vascular diseases. Larger studies are needed to confirm our results and elucidate the underlying mechanisms.

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Inefficient alveolar wound repair contributes to the development of pulmonary fibrosis. Hepatocyte growth factor (HGF) is a potent growth factor for alveolar type II epithelial cells (AECII) and may improve repair and reduce fibrosis. We studied whether targeted gene transfer of HGF specifically to AECII improves lung fibrosis in bleomycin-induced lung fibrosis. A plasmid encoding human HGF expressed from the human surfactant protein C promoter (pSpC-hHGF) was designed, and extracorporeal electroporation-mediated gene transfer of HGF specifically to AECII was performed 7 days after bleomycin-induced lung injury in the rat. Animals were killed 7 days after hHGF gene transfer. Electroporation-mediated HGF gene transfer resulted in HGF expression specifically in AECII at biologically relevant levels. HGF gene transfer reduced pulmonary fibrosis as assessed by histology, hydroxyproline determination, and design-based stereology compared with controls. Our results indicate that the antifibrotic effect of HGF is due in part to a reduction of transforming growth factor-β(1), modulation of the epithelial-mesenchymal transition, and reduction of extravascular fibrin deposition. We conclude that targeted HGF gene transfer specifically to AECII decreases bleomycin-induced lung fibrosis and may therefore represent a novel cell-specific gene transfer technology to treat pulmonary fibrosis.